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A&P 2 test yourself questions
Terms in this set (333)
Lung sacs that are the location of O2 transfer into the blood and carbon dioxide.
what are the main functions of blood?
transportation, regulation, defense
What is the most abundant component of plasma?
What is the difference between plasma and serum?
Plasma is the liquid portion of whole blood or a blood sample when the sample has not been allowed to clot. Serum is the liquid portion of a blood sample after the sample has been allowed to clot, removing the clotting elements. Plasma is prepared by centrifuging anticoagulated blood. Serum is prepared by allowing blood to clot.
What are the three main categories of blood cells?
Red blood cells (erythrocytes(, white blood cells (leukocytes), and platelets (thrombocytes)
What is the difference between red bone marrow and yellow bone marrow?
Red bone marrow is bone marrow that is actively making blood cells. Its location in the animal's body changes as the animal matures. Yellow bone marrow is inactive or fatty bone marrow that is no longer producing blood cells.
How does one cell population, the pluripotential stem cells, give rise to all the different blood cells?
A pluripotential stem cell has the potential to develop into any one of the blood cells. Which one is determined by the chemical or physiological stimulus that acts on the stem cell. Each blood cell type has its own stimuli required to activate a pluripotential stem cell to start down the path of development of that specific blood cell.
What physiologic state of blood acts as the stimulus for erythropoiesis?
what is the name of the process that produces eyrthrocytes? Leukocytes? Thrombocytes?
Erythropoiesis; leukopoiesis; thrombopoiesis
How does a red blood cell carry oxygen to tissues?
Erythrocytes carry oxygen to tissues through the production of the protein hemoglobin that binds with the oxygen. Hemoglobin is a protein composed of two components—heme and globin. Every heme group can carry a molecule of oxygen. Four heme groups attach to each globin molecule, so each hemoglobin molecule can carry four molecules of oxygen. The oxygen attaches to iron atoms (Fe++) that are part of each heme group.
Where does bilirubin come from? How is it eliminated from the body?
The heme pigment from hemoglobin is disassembled and eliminated from the body. To do this it is first converted to bilirubin, which is then carried to the liver by the plasma protein, albumin. Bilirubin has to attach itself to albumin because at this stage it is not water soluble. At this point the bilirubin is classified as unconjugated or "free" bilirubin. In the liver bilirubin is joined or coagulated to a compound called glucuronic acid. The combined bilirubin and glucuronic acid molecule is water soluble and excreted as a bile pigment into the intestines. The bilirubin is now classified as "conjugated" bilirubin. In the intestines, conjugated bilirubin is converted into urobilinogen by bacteria. Some of this urobilinogen will be reabsorbed and eliminated in the urine are urobilin. Some will be converted to another compound, stercobilinogen, and excreted in the stool as stercobilin.
What is the difference between anemia and polcythemia?
Anemia occurs when an animal's PCV is lower than the normal reference range and results in a decreased oxyegen-carrying capacity of the blood. Polycythemia is when an animal's PVC is higher than normal. Polycythemia is an increase above normal in the number of red blood cells. There are three types of polycythemia: Relative polycythemia, compensatory polycythemia, and polycythemia rubra vera.
What is a CBC?
The CBC is also known as the hemogram or complete blood count. It is used to evaluate the components of a blood sample: plasma or serum, red blood cells, white blood cells, and platelets.
How can you use the hematocrit to evaluate a patient for anemia?
The percentage of red blood cells will be decreased in anemia, which occurs when the animal's red blood cell count is low or when the red blood cells are smaller than normal.
What is the buffy coat?
The buffy coat is the layer of white blood cells and platelets that settles on top of the red blood cell column in a packed cell volume tube after centrifugation. It appears cream or buff colored. The thickness of the buffy coat can be used as an indicator of the total number of leukocytes and platelets in the sample.
Why are platelets not considered complete cells?
Platelets do not have nuclei. They are not complete cells but are pieces of cytoplasm that bud off of giant, multinucleated bone marrow cells called megakaryocytes and are sent into circulation.
What are the main functions of platelets?
Hemostasis, the process by which blood is prevented from leaking out of damaged blood vessels. Platelets have specific roles in the clotting process along with endothelial cells in the blood vessel wall and coagulation factors. The two specific functions of platelets in hemostasis are the formation of a platelet plug and stabilization of that plug, making it irreversible.
List the five types of white blood cell and indicate whether each one is a granulocyte or an agranulocyte.
Neutrophils, eosinophils, and basophils are granulocytes. Monocytes and lymphocytes are agranulocytes.
What is the common function of all white blood cells?
The function of all white blood cells is to provide defense for the body against foreign invaders.
Which cell is the only white blood cell not capable of phagocytosis?
Which white blood cell is known as PMN?
Which white blood cells is known as "the second line of defense" after a microorganism has entered the body?
which white blood cell would you likely see increased in peripheral blood during an allergic response?
Which white blood cell is least commonly seen in peripheral blood?
Which white blood cell is the largest cell normally seen in peripheral blood?
What are the four types of lymphocyte?
T cells, B cells, and natural killer cells
How does lymph differ from plasma?
Plasma is the fluid portion of whole blood and carries substances such as nutrients, oxygen, and hormones to bathe the cells and tissues. Lymph comes from plasma but is different from plasma in that it is made up of more water, sugar, and electrolytes and less of the larger proteins found in plasma.
Where is lymph found?
Lymph starts out as excess interstitial tissue fluid picked up by small lymph capillaries. The excess tissue fluid accumulates when more fluid leaves the blood capillaries then reenters them.
What is the function of a lymph node?
Lymph nodes trap antigens and other foreign material carried in lymph.
Which lymphatic organ is composed of white pulp and red pulp?
Which lymphatic organ is large at birth and gradually gets smaller as the animal matures?
Where is the GALT located?
lining of intestine
What are the goals of transfusion therapy?
The three goals of transfusion therapy are to increase oxygen-carrying capacity, to replace coagulation factors or other proteins, and to replace volume.
What is the main function of the immune system?
Protect the body from foreign invaders and prevent disease
What organs are involved in immunity?
Spleen, lymph nodes, thymus, GALT, bone marrow
Describe how the lymphatic system protects the body from disease.
Filters lymph to remove potential pathogens before they can enter the circulatory system.
Where is MALT found?
Tonsils (pharynx), adenoids (pharynx), Peyer's patches (intestines), and (in rabbits) the appendix (intestines), as well as clusters of lymphoid tissue in the gastrointestinal tract
What is the significance of the thymus?
Responsible for maturation of T lymphocytes, which are responsible for cell-mediated immunity
What are the two main subcategories of the immune system?
Innate and adaptive immunity
How does specific immunity differ from nonspecific immunity?
Specific immunity responds to particular antigens in particular ways, whereas nonspecific immunity responds to all antigens and attacks them in the same way.
Adaptive immunity is nonspecific immunity. True or false?
What is the difference between the 1st and 2nd line of defense against invading pathogens?
The first line of defense is composed of external barriers (skin, mucous membranes, secretions). The second line of defense is internal and activated only when the first line of defense fails.
The body's innate defense against viral pathogens is driven by the production of what?
What are the pros and cons of a fever?
Benefits of fever include increased rate of phagocytosis, slowed bacterial growth, and potential killing of the pathogen. Risks include denaturing of the proteins and injury to bodily tissues and cells.
What cell type of innate defense targets tumor cells?
Natural killer cells
What types of cells are phagocytic?
Neutrophils, eosinophils, monocytes, tissue macrophages. All white blood cells except lymphocytes and basophils are capable of phagocytosis.
What are the four cardinal signs of inflammation?
redness, swelling, heat, pain, loss of function
Where are B cells produced? Where do they mature?
B cells originate in the red bone marrow. B cells mature in the red bone marrow.
Where are T cells produced? Where do they mature?
red bone marrow and thymus
Which cell produces antibodies?
B lymphocytes that have differentiated into plasma cells
Describe the three stages of differentiation of lymphocytes.
Native cells have entered the lymphatic system but have not encountered an antigen. Cytotoxic or effector cells have been activated and are involved in eliminating a pathogen. Memory cells are the survivors of past infections, capable of providing long-term immunity.
Describe the function of each of the five immunoglobulins. When would the levels of each increase?
IgM: acute infections IgG: Chronic infections IgA: mucosal immunity IgE: Allergic reactions and parasitic worms IgD: Activates basophils and mast cells
Describe the three types of T lymphocytes.
Helper T cells (TH) secrete cytokines into the surrounding tissue to improve immune response. Cytotoxic T cells (TC) attach to the antigenic cells and destroy them. Regulatory T cells (TS) inhibit helper T cell and cytotoxic T cell function by negative feedback. They also prevent B cells from transforming into plasma cells.
Describe how vaccines protect patients from disease. Is this an example of active or passive immunity?
Vaccines introduce a weakened form of a pathogen to which the animal's body mounts an immune response in which memory cells are produced. This allows the immune system to respond more quickly and effectively should it encounter the natural form of the pathogen. This is an example of active immunity.
What three factors influence the ability of a pathogen to cause disease?
Virulence of the pathogen and degree of pathogenicity, immune sytem strength, and mode of infection/transmission.
Describe the three types of resistance that prevent an animal from contracting a disease. Which type of resistance prevents humans from contracting canine distemper?
Acquired resistance, Individual resistance, and species resistance, which prevents humans from contracting distemper.
Which hypersensitivity reaction is likely involved in a vaccine reaction?
Which type of blood vessel carries blood away from the heart? Toward the heart?
Arteries carry blood away from the heart; veins carry blood toward the heart.
What are the two parts of the cardiovascular system? Which part carries blood to and from the left rear leg of a pony?
The pulmonary circulation and the systemic circulation. The systemic circulation.
List three structures found in the mediastinum.
Heart, trachea, esophagus, thymus, lymph nodes, nerves
Which is located more caudally in a standing pig, the apex or the base of the heart?
What is the difference between the endocardium and the pericardium?
The endocardium is the membrane that lines the chambers of the heart. It lies on the internal surface of the myocardium; the epicardium lies on the external surface of the myocardium and the sysnonymous with the visceral layer of the serous pericardium.
Which sits closer to the base of the heart, the left atrium or the right ventricle?
The left atrium
What is the name of the structure that is a continuation of the myocardium that forms a wall between the two atria? The two ventricles?
Interatrial septum; interventricular septum
Why is the wall of the right ventricle thinner than the wall of the left ventricle?
Because the right ventricle doesn't have to pump as hard to get blood into pulmonary circulation as the left ventricle does to get blood into systemic circulation.
What is another name for each of these valves: right AV valve, semilunar valve in the left ventricle?
Tricupsid valve, pulmonary valve, mitral or bicupsid valve, aortic valve.
What is the function of the chordae tendoneae?
To prevent the AV valves from opening backward into atria
List, in order, the structures an erythrocyte will pass through (including valves) to move in a complete circuit from the left ventricle back to the left ventricle.
Aortic valve, aorta, systemic circulation, vena cava, right atrium, tricupsid valve, right ventricle, pulmonary valve, pulmonary circulation, left atrium, mitral valve, left ventricle.
What is the pacemaker of the heart and where is it located?
SA node, wall of the right atrium
List the four conductors that make up the rapid conduction system for an impulse created by the heart's pacemaker.
SA node, AV node, bundle of HIS, Purkinje fiber system
The working phase of a cardiac cycle is _______. It involves ______ that generates an impulse that results in muscle contraction.
What is happening in the other three heart chambers during left atrial diastole?
Right atrial diastole, right and left ventricular sytole
When the mitral valve is forced closed it produces part of which heart sound, the first or the second?
First sound; the sound of the AV valves closing
Stroke volume (SV) is a measurement of what?
Amount of blood ejected from the left ventricle during one contraction
If the cardiac output and stroke volume both decrease what has to happen to the heart rate to achieve equilibrium?
The heart rate will have to increase
What is the difference between the preload and the afterload in reference to the stroke volume?
The preload is the amount of blood the ventricle receives from the atrium; the afterload is the amount of physical resistance presented by the aorta.
How could mitral valve stenosis affect the stroke volume?
Decrease stroke volume because the valve is not opening all the way so less blood is being delivered to the ventricle. In other words, the preload will decrease.
From the aortic valve in the left ventricle to the right atrium, list, in order, the types of blood vessel a drop of blood will pass through.
Aorta, large to small elastic arteries, large to small muscular arteries, arterioles, capillaries, venules, small to large veins, vena cava, right atrium
The coronary artery is the first branch off the aorta. Is it a muscular or elastic artery? Why?
Elastic because is has to be able to withstand the high pressure of the blood leaving the left ventricle via the aorta
In a pregnant ewe, which are the only two veins that are carrying oxygenated blood?
The pulmonary vein that carries the oxygenated blood to the left atrium from the pulmonary circulation and the umbilical vein that carries oxygenated blood from the mother to the fetus.
What two bypass structures are found in the fetus that allow most of its blood to bypass the pulmonary circulation?
Foramen ovale and ductus arteriosus
What is the difference between a heart rate and a pulse?
The heart rate measures the number of ventricular contractions in 1 minute; the pulse measures the rate of alternating stretching and recoiling of an elastic artery wall as blood passes through it over 1 minute.
What does systolic pressure measure?
The pressure produced in an artery by the blood ejected from the left ventircle during systole
What is the difference between ECG and ECHO?
The ECG detects the electrical activity in the heart and is used to evaluate the cardiac conduction system; the ECHO uses ultrasound waves bounced off the heart to evaluate size, shape, and movement of he heart. Doppler ECHO evaluates blood flow in the heart.
Which vein can be used in most common animal species for venipuncture? Where is it located?
The bilateral jugular veins located in the jugular grooves on the ventral aspect of the neck from the mandible to the shoulder.
multipotent stem cells
cells that can self-renew for extended periods of time and differentiate into specialized cell types that have specific functions
pluripotent stem cells
cells that can develop into any cell type found in the body
volume percentage of red blood cells in the blood
non-nucleated fragments of megakaryocytes
formation of a platelet plug (not to be confused with homeostasis)
strength of a pathogen to cause disease
clusters of gut-associated lymphoid tissue (GALT) in the small intestine of animals
Pathogen-associated molecular patterns (PAMPs)
common molecules found on the membrane of pathogens and shared by large groups of pathogens
Pattern Recognition Receptors (PRRs)
receptors on macrophages or dendritic cells that bind to pathogen-associated molecular patterns (PAMPs)
conduct electrical impulses within cardiac muscle
collection of cells where normal electrical heart impulses originate (cardiac pacemaker)
very small blood vessels that collect blood from the capillaries and converge to form veins
mean arterial pressure
average arterial pressure during a single cardiac cycle
what is the primary function of the respiratory system?
Its primary function is to bring oxygen into the body and carry carbon dioxide out of it
What are secondary functions of the respiratory system?
Secondary functions include voice production, body temp regulation, acid-base balance regulation, and sense of smell
What is the difference between breathing and respiration?
Breathing also known as ventilation, is the process of drawing air into the lungs and blowing it back out again. Respiration is the process of exchanging O2 and CO2
What is the difference between internal respiration and extrenal respiration? Which one occurs in the lungs?
External respiration occurs in the lungs. It is the exchange of O2 and CO2 between the air inhaled into the lungs and the blood flowing through the pulmonary (lung) capillaries. internal respiration, on the other hand, occur everywhere in the body. It is the exchange of O2 and Co2 between the blood in the capillaries all over the body (the systemic capillaries) and all of the cells and tissues of the body. Internal respiration is the real "business end" of respiration. It is the means by which the body's cells receive the O2 they need and get rid of their waste (carbon dioxide). Without external respiration, however, there would be no O2 in the blood for the cells to absorb and no way for the cells to dump the CO2.
By what mechanisms is inhaled air warmed, humidified, and filtered as it passes through the nasal passages? How do the turbinates aid these processes?
The scroll-like twists and turns of the turbinates tremendously increase the SA of the nasal lining. They allow it to function as a combo of radiator and humidifier. The air is warmed by the blood flowing through the complex of blood vessels just beneath the nasal epithelium and humidified by the mucus and other fluids that lie on the epithelial surface. The filtering function of the nasal passages helps remove particular matter, such as dust and pollen, from the inhaled air before it reaches the lungs. The filtering mechanism relies on the many twists and turns of the nasal passages produced by the turbinates, the mucous layer on the surface of the nasal epithelium, and the cilia that project up into it. Air easily passes along the torturous path of the nasal lining as it is inhaled, but particles of dust and other debris do not negotiate the twists and turns as readily and become trapped in the mucous layer. The beating of the cilia "sweeps" the mucus and the trapped foreign material back to the pharynx, where it is swallowed.
Describe how the respiratory and digestive passageways "switch places" in the pharynx.
The respiratory passageway (nasal passage) starts out dorsal to the digestive passageway (mouth) rostrally, but further caudally, the respiratory passageway (larynx) is ventral to the digestive passageway (esophagus)
How do the pharynx and larynx work together to keep swallowed material from entering the trachea? What role does the epiglottis play in that process?
The pharynx and larynx work together to prevent swallowing from interfering with breathing, and vice versa. The seemingly simple act of swallowing actually involves a complex series of actions that stops the process of breathing, covers the opening into the larynx, moves the material to be swallowed to the rear of the pharynx, opens the esophagus, and moves the material into it. Once swallowing is complete, the opening of the larynx is uncovered and breathing resumes. The epiglottis is the structure that temporarily covers the opening to the larynx so that food can pass over it and into the rear of the pharynx and esophagus.
How is the larynx involved in the straining process that aids functions such as defecation?
Straining begins with the animal holding the glottis closed while applying pressure to the thorax with the breathing muscles. This stabilizes the thorax and allows the abdominal muscles to effectively compress the abdominal organs when they contract. Without the closed glottis, contraction of the abdominal muscles merely forces air out of the lungs (exhalation).
Why are the hyaline cartilage rings important to the function of the trachea?
The hyaline cartilage rings prevent the trachea from collapsing each time the animal inhales.
Describe the basic structure of the bronchial tree in the lung.
The trachea bifuricates to form 2 main bronchi. Each main bronchus enters the lung and divides into some fairly large branches, which divide into smaller and smaller branches called bronchioles. Bronchioles continue to subdivide down to the smallest air passageways, the microscopic alveolar ducts. These ducts end in groups of alveoli arranged like bunches of grapes, the alveolar sacs.
How do the physical characteristics of the alveoli and the capillaries that surround them facilitate the exchange of gases between the air in the alveoli and the blood in the capillaries?
Structurally, the alveoli are tiny, thin-walled sacs that are surrounded by networks of capillaries. The wall of each alveolus is composed of the thinnest epithelium in the body- simply squamous epithelium. The main physical barriers between the air in the alveoli and the blood in the capillaries are the very thin epithelium of the alveolus and the adjacent, equally thin epithelium of the capillaries. These 2 thin layers allow O2 and CO2 to freely diffuse back and forth between the air and the blood. Each alveolus is lined with a thin layer of fluid that contains a substance called surfactant. Surfactant helps reduce the surface tension (the attraction of water molecules to each other) of the fluid. This prevents the alveoli from collapsing as air moves in and out during breathing.
What is the hilus of the lung and why is it important?
The hilus is a small, well-defined area on the medial side of each lung where air, blood, lymph, and nerves enter and leave the lung. It is the only area of the lung that is "fastened in place". The rest of the lung is free within the thorax.
What is the mediastinum and what organs and structures are located there?
The mediastinum is the area between the lungs that contain most of the rest of the thoracic contents: the heart, large blood vessels, nerves, trachea, esophagus, and lymphatic vessels, and lymph nodes.
Which main pulmonary blood vessel contains bright red, high-oxygen blood: the pulmonary artery or the pulmonary vein? Why?
When a piece of lung from a dead newborn animal is dropped into water, it sinks. What conclusion can be drawn about whether the newborn animal was born dead and never breathed or took some breaths before dying?
The animal was born dead. If it had been born alive and had breathed, the lung piece would have floated.
Why are the smooth pleural surfaces important to the process of breathing?
These surfaces are lubricated with pleural fluid and ensure that the surfaces of the organs, particularly the lungs, slide smoothly along the lining of the thorax during breathing.
Why is negative intrathoracic pressure important to breathing? What happens if it is lost?
The pressure within the thorax is negative with respect to atmospheris pressure and creates a partial vacuum within the thorax, That partial vacuum pulls the lungs tightly out against the thoracic wall. The soft, flexible nature of the lungs allows them to conform closely to the shape of the inside of the thoracic wall. Pleural fluid between the lungs and the thoracic wall provides lubrication. As the thoracic wall goes, so go the lungs. The lungs follow passively as movements of the thoracic wall and diaphragm alternately enlarge and reduce the volume of the thorax. The whole system functions like a bellows as it pulls air into the lungs (inspiration) and blows it back out (expiration). Without negative pressure, the lungs would collapse and not be able to fill. In addition, blood return to the heart would be decreased.
What are the main muscles of inspiration? How do they cause air to be drawn into the lungs?
diaphragm and external intercostal muscles. When the diaphragm contracts (flattens), the thoracic cavity enlarges and the lungs expand. The fibers of the external intercostal muscles are oriented obliquely so that when they contract, they rotate the ribs upward and forward, thus increasing the size of the thoracic cavity.
What are the main muscles of expiration? How do they push air out of the lungs?
Internal intercostal muscles and abdominal muscles. The fibers of the internal intercostals run deep and at right angles to the external intercostal muscles. When they contract, they rotate the ribs backward, which decreases the size of the thorax and helps push air out of the lungs. When abdominal muscles contract, they push the abdominal organs against the caudal surface of the diaphragm. This pushes the diaphragm back into its full dome shape and also decreases the size of the thorax.
Describe the basic processes by which oxygen moves from the air in the alveoli into the blood in the alveolar capillaries and CO2 moves in the other direction.
When that air is inhaled down into the alveoli of the lungs, it is only a couple of thin epithelial layers away from the blood in the surrounding capillaries. That alveolar capillary blood contains very little oxygen but a high level of carbon dioxide because it gave up its oxygen to the body's cells and picked up their carbon dioxide as it flowed through the systemic circulation. As this low-oxygen, high-carbon-dioxide blood circulates right next to an alveolus containing high-oxygen, low-carbon-dioxide air, oxygen diffuses from the alveolar air (area of high concentration) into the blood of the alveolar capillary (area of low concentration). At the same time, carbon dioxide diffuses from the blood (area of high concentration) into the alveolus (area of low concentration). The differences in the concentrations of the gases (the concentration gradient) stay fairly constant because as the blood picks up oxygen and dumps carbon dioxide, it flows away and is replaced by more low-oxygen, high-carbon-dioxide blood. At the same time, the air in the alveoli is refreshed with each breath.
Describe how the mechanical respiratory control system maintains a normal, rhythmic, resting breathing pattern.
. Breathing is controlled by the medulla oblongata of the brain stem in an area called the respiratory center. Within the respiratory center are individual control centers for functions such as inspiration, expiration, and breath-holding that receive input from stretch receptors in the lungs that indicate when the lungs reach preset inflation and deflation limits. These centers send nerve impulses out to the respiratory muscles at a subconscious level, directing when and how much they contract. Therefore, the voluntary respiratory muscles are controlled by nerve impulses from a subconscious part of the brain
What is the basic difference between the functions of the mechanical and chemical respiratory control system?
The mechanical system sets routine inspiration and expiration limits, and the chemical system monitors the levels of certain substances in the blood and directs adjustments in breathing if they get out of balance.
When does the chemical respiratory control system kick in and override the mechanical control system?
Chemical receptors in blood vessels (the carotid and aortic bodies located in the carotid artery and aorta, respectively) and in the brain stem constantly monitor various physical and chemical characteristics of the blood. Three characteristics important to the control of the breathing process are (1) the CO2 content, (2) the pH, and (3) the O2 content of the arterial blood. If any of these varies outside preset limits, the chemical control system signals the respiratory center to modify the breathing process to bring the errant level back into balance. If the chemical control system detects a rise in the blood level of CO2 and a decrease in the blood pH (blood becomes acidic), it signals the respiratory center to increase the rate and depth of respiration so that more CO2 can be eliminated from the lungs. If the CO2 level falls too low, which is usually accompanied by a rise in the blood pH level, the opposite occurs (that is, respiration is decreased to allow the CO2 level to rise back into the normal range).
The effects of variations in the blood O2 level are not as clear cut as the CO2 effects. If a slight decrease in the blood O2 level (hypoxia) occurs, the chemical control system signals the respiratory center to increase the rate and depth of breathing so that more O2 will be taken in. If, however, the blood O2 level drops below a critical level, the neurons of the respiratory center can become so depressed from the hypoxia (lack of oxygen) that they cannot send adequate nerve impulses to the respiratory muscles. This can cause breathing to decrease or stop completely.
Why do animals cough, sneeze, yawn, sigh, and hiccup?
A cough is a protective reflex stimulated by irritation or foreign matter in the trachea or bronchi. Moist coughs, also known as productive coughs, help an animal clear mucus and other matter from the lower respiratory passages. They are generally beneficial to the animal, and we usually do not try to eliminate them with medications. Dry coughs, also known as nonproductive coughs, are generally not beneficial and are often treated with cough-suppressant medications.
A sneeze is similar to a cough, but the irritation originates in the nasal passages. The burst of air is directed through the nose and mouth in an effort to eliminate the irritant or irritants.
A yawn is a slow, deep breath taken through a wide-open mouth. It may be stimulated by a slight decrease in the oxygen level of the blood, or it may result from boredom, drowsiness, or fatigue. Yawns can even occur in humans by the power of suggestion, such as seeing someone else yawn or even thinking about yawning. (Did you just yawn?)
A sigh is a slightly deeper-than-normal breath. It is not accompanied by a wide-open mouth like a yawn. A sigh breath may be a mild corrective action when the blood level of oxygen gets a little low or the carbon dioxide level gets a little high. It may also serve to expand the lungs more than the normal breathing pattern does. Anesthetized animals are often manually given deep sigh breaths periodically to keep their lungs well expanded. This is done to prevent the partial collapse of the lungs, which can occur in anesthetized animals as a result of respiratory system depression caused by general anesthetic drugs.
Hiccups are spasmodic contractions of the diaphragm accompanied by sudden closure of the glottis, causing the characteristic "hiccup" sound. Although hiccups can result from serious conditions such as nerve irritation, indigestion, and central nervous system damage, most of the time they are harmless and temporary and occur for unknown reasons.
a mucous membrane-covered, flap of tissue made of elastic cartilage that is attached to the opening of the larynx, which serves to prevent food and other swallowed substances from entering the trachea and lungs.
the area where the lung is fixed in place on its medial side and where the blood, lymph, nerves, and air enter and exit the lungs
An enlargement of the trachea that serves as the sound-producing organ in birds
The area of the respiratory center signaled by the hypothalamus when increased blood temp. is sensed
a characteristic pattern of smooth muscle contractions that moves ingesta through the esophagus and intestines.
teeth with short crown, well-developed roots, and narrow root canals
teeth with high crowns and short roots
a bile acid structure in which the hydrophobic aspect faces inside away from water and the hydrophilic aspect pointing out toward water.
accessory digestive organs
organs lying near the GI organs that assist in digestive functions
also called hardware disease, a condition in which heavy nonfood objects enter the reticulum and pierce the wall and damage the diaphragm
the energy needed to increase the temp. of a kilogram of water by 1 degree centigrade at 1 temp of pressure
a nonprotein compound that is necessary for the functioning of an enzyme.
An inorganic molecule that some enzymes require to carry out a chemical reaction
what is the primary diet of a carnivore, omnivore, and herbivore?
meat, both meat and plants, plants
what are the two species of animal that require microbial fermentation to digest their food?
any ruminant (cow, sheep, goat, etc), horse, rabbit
what is the purpose of the stratified squamous epithelium that lines much of the GI tract?
how many layers of muscle make up the muscular layer of the wall of the intestines?
2; inner circular and outer longitudinal
what are the two nerve plexuses that make up the intrinsic enteric nervous system?
Submucosal plexus (meissenr's plexus) and the myenteric plexus (aurebach's plexus)
what are the two parts of the roof of the mouth?
hard palate and soft palate
The part of the tooth that sticks above the gum line is the ____. It is covered with____.
what substance makes up the bulk of the tooth?
The inside surface of a tooth that faces the tongue is the ___ surface.
Where is the occlusal surface of a tooth?
The surface that faces the opposite dental arch
what type of tooth will continue to grow throughout the life of an animal?
what are the four types of tooth that make up heterodont dentiton?
incisors, canines, premolars, and molars
What numeric system is used to assign a specific number to each tooth in the mouth?
The majority of the tongue is made up of what type of tissue?
Besides water, list three substances found in saliva.
protein, electrolytes, IgA, glycoproteins, bicarbonate, enzymes
what are three primary salivary glands in a dog?
Parotid, sublingual, mandibular (zygomatic)
what does TMJ mean?
When speaking of the movement of the mandible, what is translation?
movements to the side and forward
what is the structure that covers the opening of the trachea when an animal is swallowing food?
how many muscle layers are found in the esophagus?
2 (inner circular and outer longitudinal)
what is the proper medical term for the throat?
what happens during prehension. during deglutination? during mastification?
bringing food to the mouth, swallowing, chewing
Which of the three phases of swallowing is under conscious control?
the first phase that takes food to the pharynx
what is the name of the pattern of muscular contractions and dilations that moves food forward through the esophagus and other parts of the digestive system?
the serous membrane that covers the organs of the abdominal cavity is the ____?
The connecting peritoneum that links the stomach to the abdominal wall is the __.
The semiliquid, partially digested food that travels leaves the stomach and enters the duodeum is ___.
what are the four sections of a monogastric stomach?
cardia, fundus, corpus (body), pylorus
What proteolytic enzyme in the stomach begins protein digestion?
what three actions result from acetylcholine release during the cephalic phase of gastric secretion?
parietal cells release HCl, chief cells secrete pepsionogen, G cells secrete gastrin
which neurotransmitters, released by sympathetic neurons, causes a reduction in the frequency of smooth muscle contractions in the stomach?
What part of the monogastric stomach increases in size to accommodate a large meal?
What nerve can elicit opposite types of gastric movement through the release of different neurotransmitters in the myenteric plexus?
list three conditions in the duodenum that can decrease the rate of gastric emptying.
duodenal distension, hyper- or hypo-osmolarity of chyme, high concentration of protein or fat breakdown products, acidic chyme
what are the two types of digestion that take place in the stomach?
repeating units of monosaccharides make up__.
List the four chambers that make up the ruminant stomach.
rumen, reticulum, omasum, and abomasum
Which of the four chambers is the largest fermentation chamber and on which side of the animal would you look to see whether it was bloated?
which chamber is known as many piles?
what is the importance of esophageal groove?
It allows milk in a nursing ruminant to bypass the reticulorumen and go directly to the omasum. This prevents lactic acid buildup from fermentation in the reticulorumen.
explain the difference between eructation and rumination.
eructation is the process by which gas produced by the fermentation process is released from the reticulormen and passed up the esophagus and into the trachea, where it is expelled during expiration. Rumination is the process by which food is brought back to the oral cavity by antoperistalsis in the esophagus. The purpose is to chew the food more thoroughly and to add more saliva.
What does a cow do when she chews her cud?
Chewing the cud is the same as rumination.
the main source of energy in ruminants is the production of__.
volatile fatty acids
In the reticulorumen complex carbohydrates are broken down to __ or __.
monosaccharides or polysaccharides
what are the three most important volatile fatty acids produced by conversion from pyruvate?
acetate, proprionic acid, and buytric acid
lipids are found in grasses and plants in the form of (three compounds)?
triglycerides, glycolipids, free fatty acids
Proteins in ruminant diets are broken down extracellularly by peptidase into ________.
small peptide chains
Urea produced as a by-product of amino acid metabolism in the ruminant liver goes to the _______ for reuse.
What is gluconeogenesis and where in the ruminant does it mostly take place?
production of glucose from noncarbohydrate sources, liver
List, in order as they leave the stomach, the three sections of the small intestine.
duodenum, jejunum, ileum
what is the brush border in relation to the small intestine, and what is its function?
the microvilli on the villi of epithelial cells lining the small intestine. they increase the surface area of the intestinal lumen resulting in a greater surface for reabsorption. they also contain enzymes necessary for membranous digestion
what characteristics of chyme are necessary to stimulate the release of cholecytostokinin (CCK)?
high amino acid or fatty acid content, low pH
which hormone, released in the duodenum, is responsible for decreased hydrochloric acid production in the stomach?
what substance, released by the pancreas and liver into the duodenum, helps neutralize the acidic chyme leaving the stomach?
what are the two substances secreted by the exocrine portion of the pancreas?
lipase, amylase, nucleases, proteases, proenzymes
What three structures are found in the triad located at the periphery of a hepatic lobule?
portal vein, hepatic artery, bile duct
What is the function of a kupffer cells?
They are hepatic macrophages that engulf foreign substances
Where does the common bile duct under the small intestine?
Duodenum through the sphincter of Oddi
What common species of domestic animal does not have a gallbladder?
What is enterohepatic circulation?
The pathway the bile salts take from the liver to the intestines, to the portal vein, and back to the liver. The circulation bypasses systemic circulation
Unconjugated Billy Rubin in blood is not water-soluble. How does it become water soluble?
It combines with plasma proteins albumin and is transported to the liver, where it is taken in by a hepatocyte. In the hepatocytes, it is conjugated with glucuronic acid and becomes water soluble
The major storage form of glucose is
How are triglycerides in adipose tissue converted into glucose for energy?
In adipose tissue lipase breaks down the triglyceride into glycerol and fatty acids that are transported to various tissues, including the liver. In the liver glycerol is converted to glucose by gluconeogenesis; in other tissues the fatty acids are oxidized to produce energy.
Which plasma proteins produced in the liver plays a crucial role in fluid movement between plasma and interstitial fluid?
Which movement in the small intestine propels intestinal fluid?
In the luminal phase of the chemical digestion of starches, which Enzyme, secreted by the pancreas, is needed?
In the membranous phase of chemical digestion of sugars, where are the necessary enzymes located?
Embedded in the brush border of the intestinal epithelium
What is an exopeptidase?
An enzyme that breaks off amino acid at the end of a polypeptide chain
Both glucose and amino acids are brought into a cell through secondary active transport? What does this mean?
The sodium-potassium pump is creating a concentration gradient that favors movement of sodium into a cell. Glucose and amino acids can ride along with the sodium into the cell, even against a favorable concentration gradient.
List the four parts of the large intestine
cecum, colon, rectum, anus
Which species of large animal is a Hindgut fermenter?
Horse or rabbit
Name a common species of animal that has a short ascending colon?
Dog, cat, any carnivore
Name a common species of animal that has a spiral ascending colon shaped like a cone?
What is the purpose of the sacculations?
They prolong the time contents stay in the large intestine; they create extra volume; they allow for more time for absorption and microbial digestion.
What are the four movements associated with the large intestine?
Peristalsis, antiperistalsis, segmentation, mass movement
How are feces formed?
Water is removed from Chyme
What is a calorie?
A calorie is the amount of energy needed to raise the temperature of 1 kilogram of water 1 degree Celsius.
what are the six fundamental nutrients? which ones generate energy when consumed?
Proteins, fats, carbohydrates, vitamins, minerals, and water are the six fundamental nutrients. Proteins, lipids, and carbohydrates generate energy when consumed.
why is water so vital to the survival of an animal?
Water is involved in almost all of the metabolic processes of the body. It is the major component of blood and is found inside all cells (intracellular) as well as outside the cell (extracellular). It is a lubricant for body tissues, a circulatory and transport medium, and a chemical reactant in digestion (hydrolysis). In addition, water is excreted as sweat and evaporated during panting to assist in temperature regulation. Finally, it is the medium in which the biochemical reactions of metabolism occur, such as those involved in the growth, repair, and maintenance of cells.
what are the 3 categories of carbohydrates?
sugars, starches, cellulose
what are the four major categories of a lipid?
Neutral fats, phospholipids, steroids, and other lipoid substances
what is the difference between a saturated and an unsaturated fat? why is this difference important nutritionally?
Saturated fatty acids have single bonds between the carbon atoms and can accommodate the greatest number of hydrogen atoms attached to the chain of carbon atoms. Saturated fatty acids tend to have long chains and are primarily found in meat and dairy foods such as milk, cream, cheese, lard, and butter. Coconuts are one of the few plant sources of saturated fats. Alternatively, unsaturated fatty acids have one or more double bonds between the carbon atoms and can accommodate fewer hydrogen atoms. These are found in seeds, nuts, and most vegetables.
What is an essential fatty acid?
Essential fatty acids are ones that the body cannot manufacture and must be provided in the diet.
give a specific example of a steroid.
what is the principal building-block unit of protein? how are these units arranged?
Amino acids are the principal building blocks of proteins. They are arranged like pearls on a string. The acid group from one amino acid links to the basic group on the next, forming a peptide bond.
what are the four basic components of an amino acid molecule? which parts of the molecule change to create the different kinds of amino acids?
Amino acids are composed of a central carbon atom, an amino group (NH2), a carboxyl group (COOH), and a variety of side chains ("R" group). Differences in the "R" group make each amino acid unique.
some amino acids cannot be synthesized in the body and must be provided in the diet. what are these amino acids called? can you give an example of one in cats? Can you give an example of one in birds?
Essential amino acids cannot be synthesized in the body. Taurine is an essential amino acid for cats, and glycine is essential for birds.
what is cellular metabolism? can you think of routine cellular process that represent specific examples of cell metabolism?
Cellular metabolism encompasses all the biochemical events involved in building molecules and breaking down nutrients, manufacturing, packaging, and excreting. Making proteins is one very important example of cellular metabolism.
cellular metabolism is divided into two categories. what are they?
anabolism and catabolism
what is the first stage of cellular catabolism called? is energy produced or consumed?
The first stage of catabolism is called hydrolysis. Energy is produced.
is energy produced or consumed during an anabolic process? what is an example of anabolism?
Energy is consumed during the anabolic process. Examples include the production of fat molecules by combining glycerol and fatty acid molecules, and the creation of proteins by joining amino acids.
what cellular process represents the largest demand for protein and enzymes?
Why are enzymatic reactions considered highly specific?
Enzymatic reactions are highly specific because one enzyme reacts only with one substrate or combination of substrates.
What is a substrate? what is a product?
Each enzyme reacts with a particular molecule called a substrate to produce a new molecule called a product.
Why is the total number of enzymes present in the body relatively low, when compared with the number of metabolic reactions?
enzymes are recycled and used over and over again. once an enzyme has catalyzed one reaction, it is free to catalyze another reaction. in this way, a few enzymes can carry out many metabolic reactions.
what is the energy of activation in a biochemical reaction?
The energy of activation is the energy needed to initiate a biochemical reaction.
What is a catalyst? why are enzymes considered catalysts?
A catalyst is a substance that speeds up a reaction. Enzymes are catalysts because they speed up reactions by lowering the activation energy.
how can you tell that a molecule is an enzyme? list three characteristsics of enzymes.
(1) An enzyme's name ends with the suffix -ase. (2) The enzyme is usually named for the substrate on which it acts. For example, proteinases are enzymes that break down protein, lipase breaks down lipid, and lactase breaks down lactose. (3) The name of the enzyme may also indicate the kind of reaction that the enzyme initiates. For example, synthetases are enzymes that synthesize or make new substances, and transferases are enzymes that move one part of a molecule to another molecule. Phosphotransferase, for example, is an enzyme that transfers a phosphate group from one molecule to another molecule.
what are some specific examples of cofactors?
The magnesium ion is a cofactor in reactions that involve the transfer of a phosphate group and is therefore found in virtually all cells. Elements such as iron, zinc, or copper, for instance, are needed to complete the shape of a binding site and are called cofactors.
how might vitamins play a role in enzyme-driven reactions?
Vitamins are nonprotein organic substances whose derivatives may act as cofactors, specifically called coenzymes. They may be bound temporarily or permanently to the enzyme and are usually located near the active site.
how is energy stored in molecules? when is it released?
Energy is stored in the atomic bonds of molecules such as ATP, NADH, and FADH2. In these convenient molecular packages, energy can be stored for extended periods and easily transported to regions of the cell where energy is in demand. Energy is released when part of the molecule is broken off. For example, in ATP, energy is released when a phosphate group breaks off.
give 3 examples of energy-holding molecules.
ATP, NADH, FADH2
what is the most common carbohydrate found in blood?
where does carbohydrate metabolism begin in nonruminant animals?
Carbohydrate metabolism begins with the breakdown of glycogen or glycerol in the liver.
What part of carbohydrate metabolism occurs in the cytoplasm?
Glycolysis breaks down glucose to form pyruvate in the cytoplasm.
under what conditions is lactic acid formed in muscle cells?
Lactic acid forms when oxygen is depleted.
How many biochemical steps are involved in glycolysis? Does glycolysis require oxygen?
Glycolysis involves 10 steps. No, it does not require oxygen.
cellular respiration is composed of what two parts?
Anaerobic (glycolysis) and aerobic respiration (Krebs cycle and the electron transport chain)
how does the membrane structure of the mitochondrion assist in the process of cellular respiration?
The inner membrane of the mitochondrion houses a series of cytochrome molecules, which make up the electron transport system. As electrons are passed from one cytochrome molecule to another, energy is released and used to transport protons from the mitochondrial matrix across the inner membrane to the intermembrane space. Because protons are positive, this establishes a positive charge on the outside of the inner membrane relative to the matrix side. The electrical gradient that is established is a form of stored (potential) energy. Energy is released when protons rush back into the mitochondrial matrix.
what role does oxygen play in the electron transport system?
At the end of the electron transport chain, oxygen accepts the low-energy electrons, joins with hydrogen ions, and forms water (H2O). Thus oxygen is the final acceptor of the electrons.
What is oxidative phosphorylation?
Oxidative phosphorylation is the process in which ATP is produced as electrons are transferred from NADH or FADH2 to O2 by a series of electron carriers in the electron transport chain. This is the major source of ATP in aerobic organisms.
what is the maximum number of ATP molecules that can be formed from the catabolism of one molecule of glucose?
what are transamination and deamination?
Transamination occurs when the amine group from an amino acid is transferred to a different keto acid. In the process, a new and different amino acid is made. Deamination occurs when the amine group from an amino acid is removed from the amino acid molecule forming one molecule of free ammonia and one keto acid molecule.
list the 3 steps involved in performing a urinalysis
The three major steps in a urinalysis are:
a. A gross examination of the physical properties of the sample.
b. A chemical analysis of substances dissolved in the urine.
c. A microscopic examination of the solid components in the urine.
What are the 6 structures that make up the urinary system?
Two kidneys, two ureters, one urinary bladder, and one urethra
nitrogenous waste materials from protein breakdown are eliminated from the body primarily as what?
name 1 hormone whose release is regulated by the kidney, 1 hormone that directly affects kidney function, and 1 hormone produced by the kidney.
The release of antidiuretic hormone is regulated by the kidneys, aldosterone directly affects kidney function, and erythropoietin is produced by the kidneys.
what is the difference between the hilus of the kidney and the renal pelvis?
The hilus is the area on the medial side of each kidney where blood and lymph vessels, nerves, and the ureter enter and leave the kidney. The renal pelvis is inside the hilus and is a urine collection chamber at the beginning of the ureter.
what is meant by the term retroperitoneal?
Retroperitoneal means outside of the abdominal cavity, between the parietal peritoneum and the dorsal abdominal muscles.
list, in order, the parts of the nephron. indicate whether each specific part is found in the cortex or the medulla of the kidney.
1. Renal corpuscle (cortex)
2. Proximal convoluted tubule (cortex)
3. Loop of Henle (medulla and cortex)
4. Distal convoluted tubule (cortex)
what is the difference between glomerular filtrate and tubular filtrate?
Glomerular filtrate is the fluid that leaves the glomerular capillaries and enters the capsular space. It is similar to plasma, but without proteins. It contains waste products that need to be cleared from the body, as well as important substances that the body needs, such as sodium, potassium, calcium, magnesium, glucose, amino acids, chloride, bicarbonate, and water. Glomerular filtrate enters the proximal convoluted tubule and is termed tubular filtrate, which travels through the tubular part of the nephron. The important substances are reabsorbed from the tubular filtrate back into the body along with some urea. The body eliminates some waste products by secreting them into the tubular filtrate. Examples include hydrogen, potassium, ammonia, and some drugs.
what is the function of the brush border on the epithelial cells of the proximal convoluted tubule?
The brush border increases the cellular surface area exposed to the fluid in the tubule by a factor of about 20. This is especially important to the PCT's reabsorption and secretion functions.
how does the blood in the efferent glomerular arteriole differ from the blood in the afferent glomerular aterirole?
Blood in the afferent glomerular arteriole of the kidney gives up all of the small molecules that can fit easily through fenestrations in the glomerulus. These include electrolytes, bicarbonate, glucose and water. Consequently, the blood of efferent glomerular arterioles is composed of large molecules such as proteins and blood cells including platelets. An exception is oxygen, which is not given up by the red blood cells until the blood has entered the efferent arteriole. Here oxygen nourishes the cells of the nephron. Ultimately, the valuable electrolytes, buffers, glucose and water needed by the body are resorbed by the nephron and put back into the blood stream.
what is the difference between tubular reabsorption and tubular secretion?
The glomerular filtrate contains substances found in plasma that the body doesn't want to lose because it needs them to maintain homeostasis. Tubular reabsorption involves removing these substances from the tubular filtrate. The useful substances are reabsorbed from the tubules into the peritubular capillaries.
Many waste products and foreign substances are not filtered from the blood in sufficient amounts from the glomerular capillaries. The body still needs to get rid of these substances, so it transfers them from the peritubular capillaries into the tubular filtrate in the tubules to be eliminated in urine.
How does ADH deficiency affect urine volume? What is the mechanism?
Insufficient ADH will increase urine volume. ADH acts on the distal convoluted tubules to promote water reabsorption into the body. If ADH is absent, water will not be reabsorbed and will be lost in urine.
what is the mechanism by which glucose and amino acids are reabsorbed out of the proximal convoluted tubule and back into the body?
As the glomerular filtrate enters the lumen of the PCT, sodium is actively pumped out of the fluid and back into the bloodstream. Sodium in the tubular filtrate attaches to a carrier protein that carries it into the cytoplasm of the PCT epithelial cell. The transfer of sodium from the tubular lumen into the epithelial cell requires energy. At the same time glucose and amino acids attach to the same protein as sodium and follow the sodium into the epithelial cell by passive transport. Glucose and amino acids passively diffuse out of the tubular epithelial cell into the interstitial fluid and then into the peritubular capillaries.
explain the concept of the renal threshold of glucose.
The renal threshold of glucose is the amount of glucose that can be reabsorbed by the proximal convoluted tubules. If the blood glucose level gets too high, the amount of glucose that is filtered through the glomerulus exceeds the amount that can be reabsorbed (the renal threshold) and the excess is lost in urine. Fortunately, the renal threshold exceeds the normal amount of glucose found in blood, so 100% of the glucose filtered through the glomerulus is reabsorbed back into the body, and no glucose is lost in the urine. However, in pathologic conditions such as uncontrolled diabetes mellitus, where blood glucose levels can be extremely high because of insufficient insulin production, the amount of glucose filtered through the glomerulus exceeds the limit that can be reabsorbed by the PCT.
explain why proteinuria occurs with renal failure.
In a normal kidney, large molecules such as protein are too big to fit through glomerular fenestrations and are retained in blood. During some types of kidney disease, the glomerulus is damaged, resulting in enlarged fenestrations and protein passing through them into urine.
why are clinical signs of renal failure not observed until the disease process is advanced?
There are often no clinical signs of chronic renal failure until 65% to 75% of the nephrons in both kidneys are nonfunctional. For this reason, long-term kidney disease is often not detected until very late in the disease.
diabetes insipidus gets its name from what physical characteristics of urine produced by patients with this disease?
The word insipid means tasteless. The disease diabetes insipidus was given its name because clinically it looked similar to diabetes mellitus, but the urine was "tasteless" rather than sweet because it didn't contain glucose.
how do the kidneys respond to a decrease in blood pressure?
When blood pressure falls, the juxtaglomerular cells within the renal cortex release an enzyme called renin. Renin causes the formation of angiotensin I from angiotensin. Angiotensin I is subsequently converted to angiotensin II by another enzyme, angiotensin converting enzyme (ACE). Angiotensin II causes the arteries in the body to constrict. It also causes and the release of aldosterone from the adrenal gland, which is located near the kidney. Aldosterone stimulates the kidney to reabsorb sodium and water back into the bloodstream, which increases both blood volume and blood pressure.
why is it important that the ureters have an inner lining of transitional epithelium?
The transitional epithelium allows the ureters to stretch as urine is passed through them on its way to the urinary bladder.
What prevents urine from backing up into the ureters when the bladder wall contracts to expel urine?
The ureters enter the urinary bladder at such an oblique angle that when the bladder is full it collapses the opening of the ureter, preventing urine from backing up into the ureter. However, it doesn't prevent more urine from entering the bladder, because the strength of the peristaltic contractions is enough to force the urine through the collapsed opening into the urinary bladder.
the ureter is continuous with what structure in the kidney (except in cattle)?
How does the bladder know when to empty itself?
The urinary bladder constantly accumulates urine until the pressure of the filling bladder reaches a certain "trigger" point that activates stretch receptors in the bladder wall. When the trigger point is reached, a spinal reflex is activated that returns a motor impulse to the bladder muscles. The muscles of the bladder wall contract. These contractions are responsible for the sensation of having to urinate. In animals that are not housebroken, emptying of the bladder will occur at this point.
What part of the urinary bladder is under voluntary control and allows an animal to be housebroken?
the muscular sphincter around the neck of the bladder
Does urine production stop when the urinary bladder is full?
No, the kidneys continue to produce urine regardless of the volume of urine present in the bladder.
Besides its urinary function, what other function does the urethra play in a male animal?
In males the urethra also has a reproductive function. The vas deferens and accessory reproductive glands enter the urethra as it passes through the pelvic canal. Here spermatozoa and seminal fluid are discharged into the urethra during ejaculation and pumped out as semen. At the beginning of ejaculation the sphincter at the neck of the urinary bladder closes, preventing semen from entering the bladder and mixing with urine.
How much kidney function must be destroyed before clinical signs of renal dysfunction become evident?
Two thirds of the total nephrons in both kidneys must be nonfunctional before clinical signs of renal dysfunction start to become evident.
explain the difference between prerenal uremia and postrenal uremia?
Prerenal uremia is associated with decreased blood flow to the kidneys and may be caused by conditions such as dehydration, congestive heart failure, or shock if these conditions are left untreated. In these cases the kidneys are functioning normally but not enough blood is reaching them, so waste materials can't be adequately removed. Postrenal uremia is usually associated with an obstruction that prevents urine from being expelled from the body. Tumors, blood clots, or uroliths (stones) can cause the obstruction. Eventually urine backs up into the kidney pelvis and then into the nephrons, increasing pressure in the nephrons and causing nephron damage.
What is a urolith?
A stone anywhere in the urinary system (kidneys, ureters, urinary bladder, or urethra)
Name two conditions that can predispose an animal to urolith production.
Diet and the presence of certain bacteria associated with urinary tract infections can influence the pH of urine to favor the precipitation of crystals and, eventually, uroliths. A housebroken animal that must consistently hold its urine for long periods of time has a decreased crystal transit time through the lower urinary tract (bladder and urethra) and is predisposed to urolith production.
How do uroliths in cats differ from uroliths in other species?
They are much smaller and resemble sand rather than large stones.
what is the chemical composition of a struvite crystal?
Struvite crystals are composed of magnesium, ammonium, and phosphate.
how does the reproductive system differ from other body systems?
The rest of the body's systems work to ensure the survival of the individual animal they are part of, whereas the reproductive system works to ensure the survival of the species of animal. It interacts with other body systems, but purely reproductive structures are not essential to the life of an animal. Another difference from other body systems is that the reproductive system requires a second animal (of the opposite sex) to fully carry out its function, which is to produce a brand-new animal (the offspring).
why is the reproductive system of an individual animal considered only half a system?
It is considered only half a system because it requires a second animal (of the opposite sex) to fully carry out its function.
what is the difference between the diploid chromosome number and the haploid chromosome number/ in which body cells is each found?
The total number of chromosomes in the nucleus of each of the body's cells (except for the reproductive cells) is the same for all members of a species. This number is called the diploid chromosome number, which is always an even number because the chromosomes occur in pairs. The diploid chromosome number is sometimes expressed generically with the abbreviation 2n. The n is a mathematical expression that represents a number, and the 2 indicates that the number is doubled (diploid). The number of chromosomes in the reproductive cells is half the number in all other cells in the body. This is called the haploid chromosome number. It has to be reduced to half the diploid number so that when the spermatozoon and the ovum come together, the total number of chromosomes in the fertilized ovum gets back to the diploid number.
Which gamete, the ovum or the spermatozoon, determines the genetic sex of the offspring when fertilization occurs?
how does cell division by meiosis differ from cell division by mitosis?
. Most of the body's cells divide through a process called mitosis. When a cell divides by mitosis, each of its chromosomes first produces a duplicate copy of itself. When the two daughter cells pull apart, half the chromosomes go to one cell and half go to the other. Each of them ends up with an identical full diploid set of chromosomes. The two daughter cells have exactly the same genetic makeup as each other and as the parent cell. This ensures that the genetic information in all of the body's cells (except for the reproductive cells) stays exactly the same. Reproductive cells are produced by meiosis, in which the chromosomes do not produce duplicate copies of themselves before the daughter cells pull apart. Half of the total chromosomes (one from each diploid chromosome pair), including one sex chromosome, go to each daughter cell. Which chromosomes go to which daughter cell is entirely random. The chromosomes merely pull apart into their new cells. In this way the genetic material of the reproductive cells gets shuffled, resulting in genetically unique offspring.
How does spermatogenesis differ from oogenesis? why are the basic processes so different?
Spermatozoa are produced continuously and in very large numbers in an effort to ensure that one spermatozoon will successfully reach and fertilize the ovum when breeding occurs, so the process of spermatogenesis is designed to produce huge numbers of spermatozoa. Alternatively, ova are not produced continuously like spermatozoa. At or soon after birth, a female has a fixed number of primary oocytes (the precursor cell to ova) formed in her ovaries. That will be the total number available in her lifetime. They remain in a quiet, immature state until the ovarian cycles begin. Each ovarian cycle produces one or more mature ova, depending on the species. Because spermatozoa come to the ovum to fertilize it, large numbers of ova are not needed. Therefore, the process of oogenesis is designed to produce small numbers of ova at a time.
what are the two main functions of the testis? Where in the organ does each take plae?
Spermatogenesis takes place in seminiferous tubules, and hormone production occurs in interstitial cells between the seminiferous tubules.
what are the three main parts of a spermatozoon? what is the main purpose or function of each?
The three main parts of a spermatozoon are an enlarged head, a midpiece, and a long, narrow tail. The head contains the nucleus of the cell and is covered by a caplike structure called the acrosome. The acrosome contains digestive enzymes that are released once the spermatozoon is inside the female reproductive tract, helping the spermatozoon reach the ovum and penetrate through the layers surrounding it to accomplish fertilization. The midpiece is the power plant of the cell. It contains a large concentration of energy-producing mitochondria arranged in a spiral pattern. The long, thin tail resembles the flagellum that many single-celled organisms use for propulsion. It contains musclelike contractile fibrils that produce a whiplike movement of the tail and propel the cell forward once it is activated.
Why is a bilaterally cryptorchid animal usually sterile?
A bilaterally cryptorchid (undescended testes) animal is usually sterile because spermatogenesis requires a temperature slightly lower than body temperature. The interior of the abdomen is too hot for spermatozoa to be produced. Testosterone continues to be produced, however. So a bilaterally cryptorchid animal has all the characteristics of a male animal but cannot reproduce.
Would a bilaterally cryptorchid animal exhibit normal male behavior? Why or why not?
Yes, because testosterone, which is responsible for the male libido, continues to be produced. Therefore, a bilaterally cryptorchid animal has all the characteristics of a male animal but cannot reproduce.
what is important about the scrotum's ability to adjust the position of the testes relative to the body?
The testes have to be kept slightly cooler than body temperature to produce spermatozoa. A bandlike muscle, the cremaster muscle, passes down through the inguinal ring and attaches to the scrotum. It can adjust the position of the testes relative to the body. In warm conditions, the cremaster muscle relaxes, and the testes hang down away from the warm body. This position helps to reduce their temperature. In cold conditions, however, the cremaster muscle pulls the testes up tight against the body wall, which helps to warm them.
what are the main components of the spermatic cord?
Spermatic cords are tubelike connective tissue structures that contain blood vessels, nerves, lymphatic vessels, and the vas deferens. Surrounding the artery is a structure called the pampiniform plexus, which is an intricate meshwork of tiny veins derived from the testicular veins.
from what are the visceral and parietal vaginal tunics that cover the testes derived?
They are derived from layers of peritoneum that were pushed ahead of the testes as they descended through the inguinal rings. The very thin inner layer, the visceral vaginal tunic (also known as the proper vaginal tunic), is derived from the visceral layer of peritoneum that coated the testes as they developed in the abdomen. The thick outer layer, the parietal vaginal tunic (also known as the common vaginal tunic), is derived from the parietal layer of peritoneum that lines the abdominal cavity. It forms a fibrous sac around each testis and spermatic cord.
where are spermatozoa stored before ejaculation?
Will the volume or gross appearance of the semen of an animal that has had a vasectomy be significantly different from that of a normal animal? Why or why not?
Because sperm typically account for less than 1% of seminal fluid, their absence after a vasectomy is negligible in terms of both the amount and gross appearance of the seminal fluid.
how does the function of the bulbourethral glands differ from those of the other accessory reproductive glands?
They secrete a mucinous (mucus-containing) fluid just before ejaculation that clears and lubricates the urethra for the passage of semen. The fluid from the bulbourethral glands is secreted in advance of the ejaculate and does not contribute greatly to its volume, composition, or function.
what are the three main parts of the penis?
roots, body, glans
what structures do spematozoa pass through from their site of production to their eventual deposition in the female reproductive tract?
Spermatozoa pass through the seminiferous tubules, rete testis, efferent ducts, epididymis, vas deferens (including the ampulla in some species), and urethra.
what two main types of hormones are produced in the ovary? where is each produced
The hormones produced in the ovaries are estrogens and progestins. Estrogens are produced by the cells of the developing ovarian follicles. Progestins, principally progesterone, are produced by the corpus luteum, which develops from the empty follicle after ovulation.
what changes does an ovarian follicle undergo as it develops from a primoridial follicle to a mature follicle?
The beginning stage of follicle development in the ovary is the primordial (sometimes called the primary) follicle. After FSH is released from the anterior pituitary, the follicle undergoes follicular recruitment or follicular activation and is now called a growing follicle. The follicular cells become thickened into cuboidal shapes and begin to multiply. Multiple layers of follicular cells form around the developing oocyte. At this stage the follicular cells are called granulosa cells. As the granulosa cells multiply, the follicle starts to grow rapidly in size. The granulosa cells do more than just physically surround the developing oocyte. They also produce estrogen hormones that begin preparing the animal for breeding and pregnancy. The larger the follicle or follicles become, the greater the amount of estrogens produced. As the follicle continues to grow, fluid-filled spaces begin to form between the granulosa cells. The spaces gradually become confluent (join together), forming one large fluid-filled space called the antrum.
When the follicle has reached its maximum size, it looks like a large blisterlike structure on the surface of the ovary. At this stage it is called a mature follicle. Alternative names for the mature follicle include graafian follicle and vesicular ovarian follicle. At this stage, estrogen production from the follicle or follicles is at maximum level, and the animal is ready for breeding to take place.
after ovulation has occurred, what cells in the ovary multiply to form the corpus luteum?
When ovulation occurs, what causes the ovum to enter the oviduct?
When ovulation takes place, the ovum is "caught" by the fimbriae of the infundibulum. The infundibulum is the enlarged opening at the ovarian end of each oviduct. At the time of ovulation, it more or less surrounds the area of the ovary where follicles have formed. The fimbriae are muscular, fingerlike projections that form the margin of the infundibulum. They "feel" along the surface of the ovary and position the infundibulum where the follicle or follicles are located. This helps ensure that the infundibulum is properly positioned to catch the ovum or ova when ovulation occurs. If ova miss the opening of the oviduct, they fall into the abdominal cavity, where they usually just disintegrate after a time.
describe the functions of the uterus relating to pregnancy and parturition.
The uterus is the womb, where the fertilized ovum implants and lives while it grows and develops into a new animal. When fully developed, the uterus helps push the newborn out through the birth canal into the outside world. It forms part of the placenta, which is the life-support system that keeps the fetus alive while it develops during pregnancy. The uterus has to remain quiet during the pregnancy and contract powerfully at the time of birth. After it has delivered the newborn and the placenta (the afterbirth), it has to contract quickly to stop bleeding from the site where the placenta was attached to its lining. The uterus is vital to the success of reproduction.
The fertilized ovum implants in the uterus and begins development. As the offspring develops, the placenta forms around it and attaches to the lining of the uterus so that nutrients, wastes, and respiratory gases can be exchanged between the fetal bloodstream and the maternal bloodstream. When the time comes for the offspring to be delivered, the muscular uterus provides most of the force necessary to open (dilate) the cervix so that the fetus can pass through it on its way to the outside world.
where is the urethral opening located in the female?
In females, the urethra opens on the floor (ventral portion) of the vestibule, which is part of the vulva (the part that is considered the entrance to the vagina).
what is the difference in the estrous cycle intervals of polyestrous, seasonally polyestrous, diestrous, and monoestrous animals?
Polyestrous animals, such as cattle and swine, cycle continuously throughout the year if they are not pregnant. As soon as one cycle ends, another begins. Some polyestrous animals show seasonal variations in their estrous cycles. They cycle continuously at certain times of the year and not at all at others. These animals are called seasonally polyestrous animals. Diestrous animals have two cycles per year, usually in the spring and fall. Monoestrous animals usually have only one cycle each year.
How do the stages of the estrous cycle relate to the physical events of the ovarian cycle?
The estrous cycle stages are proestrus, estrus, metestrus, and diestrus. Anestrus occurs in some animals between breeding seasons. Proestrus is the period of follicular development in the ovary. During this stage, follicles begin developing and growing. As they increase in size, the follicles' output of estrogen increases accordingly, causing many physical changes that prepare the rest of the reproductive tract for ovulation and breeding. These changes include thickening and development of the linings of the oviduct, uterus, and vagina. The epithelial lining of the vagina also begins cornifying, that is, forming a layer of tough keratin on its surface to help protect against the physical trauma of breeding that is about to come.
Estrus is the heat period, or the period of sexual receptivity in the female. It occurs when the estrogen level from the mature follicles reaches its peak. This high estrogen level causes physical and behavioral changes that signal the female's willingness to breed to the male.
Metestrus is the period after ovulation when the corpus luteum develops. The granulosa cells left in the now-empty follicle begin to multiply under continued stimulation from LH. They soon produce a solid structure, the corpus luteum (yellow body), which is about the same size as the former mature follicle. The hormone progesterone produced by the corpus luteum temporarily inhibits follicular development in the ovary, causes the lining of the uterus to get very thick in preparation for implantation of a fertilized ovum, and causes loss of the cornified epithelial lining that developed in the vagina during proestrus and estrus.
Diestrus is the active luteal stage when the corpus luteum has reached maximum size and exerts its maximum effect. If the animal is bred and becomes pregnant, the corpus luteum receives an endocrine signal from the developing embryo and is retained well into the pregnancy. If the animal is not pregnant, the corpus luteum degenerates at the end of diestrus. The animal either goes back into proestrus or the ovary shuts down and the animal goes into anestrus. Anestrus is a period of temporary ovarian inactivity seen in seasonally polyestrous, diestrous, and monoestrous animals. It is the period between breeding cycles when the ovary essentially shuts down temporarily.
why is the timing of copulation so important? how is the precise timing accomplished?
Timing is important because the spermatozoa must arrive at the oviducts before the ovum to have time to undergo capacitation, a process that enhances their fertility. Nature has an exquisite method for arranging the proper timing. Breeding is only allowed by the female during the estrus, or heat, period. So spermatozoa enter the female reproductive tract when the oocyte in the follicle is fully developed but has not yet been released. Release of the ovum (ovulation) is delayed until near the end of the estrus period in most species. This nifty bit of traffic control helps ensure that the spermatozoa arrive at the oviducts first and have time to undergo capacitation before the ovum shows up ready to be fertilized.
describe what happens to a zygote between fertilization and implantation.
The fertilized ovum is called a zygote. Immediately after fertilization, the nucleus of the spermatozoon is called the male pronucleus and the nucleus of the ovum is called the female pronucleus. Each carries the haploid chromosome number. The male and female pronuclei quickly join together to restore the diploid chromosome number and determine the unique genetic makeup of the offspring. As soon as the two pronuclei join to form a single nucleus, the zygote begins to divide rapidly by the normal process of mitosis. This rapid division is called cleavage. The single cell divides into 2 cells, which quickly divide into 4, then 8, then 16, and so on. Cleavage occurs so rapidly that the cells of the zygote do not have time to grow between divisions. The number of cells making up the zygote is increasing dramatically, but its overall size is still about the same as the original ovum, even after several days. While cleavage is taking place, the zygote slowly moves down the oviduct toward the uterus. Delicate, muscular contractions and the movements of cilia are gently propelling it along. After a few days the zygote is a solid mass of cells that looks like a tiny raspberry; this is known as the morula stage. The cells of the morula continue to divide and gradually form a hollow cavity in the center. By the time it reaches the uterus a few days later, it is formed into a hollow ball of cells with a bump on one side that eventually forms into the embryo. It is now called a blastocyst, and it is ready to implant itself in the lining of the uterus.
Why is the placenta so important to a successful pregnancy?
The placenta is a life-support system for the developing fetus. The fetus receives all the nutrients and other substances it needs to grow and develop from its mother through the placenta. It also depends on her to dispose of the waste products it produces. Fortunately, the placenta grows right along with the fetus and meets its needs.
describe the relationship between the fetus and the amniotic and allantoic sacs of the placenta.
The placenta consists of layers of soft membranes that form two fluid-filled sacs around the developing fetus. The layer immediately around the fetus is called the amnion. It forms a sac around the fetus called the amniotic sac. The fetus floats in amniotic fluid inside this sac. Surrounding the amniotic sac is another layer called the allantois, which forms the fluid-filled allantoic sac. The outside of the allantoic sac is covered by the chorion, which attaches to the uterine lining. The chorion is linked to the fetus by the umbilical cord.
describe the main structures that make up the umbilical cord and the function of each
The umbilical cord is a tubelike structure that contains blood vessels (the umbilical arteries and vein) and a drainage tube from the fetus's urinary bladder (the urachus). The two umbilical arteries carry unoxygenated, waste-filled blood from the fetus to the placenta. The single umbilical vein carries nutrient- and oxygen-rich blood back from the placenta to the fetus. The urachus is a tube that runs from the cranial tip of the fetus's urinary bladder through the umbilical cord to the allantoic sac. The kidneys of the developing fetus are not fully functional through most of the pregnancy; therefore, they do not produce urine as we know it. They do, however, produce a watery fluid that must be removed from the urinary bladder. The urachus drains this fluid out into the allantoic sac.
Which type of placental attachment is the simplest and detaches most easily after parturition? which is most complicated and most often results in retention of the placenta?
Diffuse attachment is the simplest and detaches most easily. Cotyledonary attachment is the most complicated type and often results in retention of the placenta.
what are the basic events of the three trimesters of pregnancy?
During the first trimester, the newly implanted zygote is getting itself organized and developing its life-supporting placenta. The developing offspring is often referred to as an embryo. During the second trimester, the developing offspring is usually called a fetus. This is the fetal development period, when all of the various parts of the fetus (tissues, organs, and systems) are taking shape and differentiating from each other. The third trimester is the period of fetal growth, when all parts of the fetus grow dramatically as it prepares to become a free-living being after birth.
describe the three stages of labor
The first stage of labor consists of uterine contractions. The muscle of the uterus (the myometrium) contracts, pressing the membrane-covered fetus down against the cervix and causing the cervix to gradually dilate. Externally, the dam appears restless and uncomfortable. She may repeatedly lie down and get up and may urinate frequently. Some species, such as the dog and pig, may attempt to build a nest into which they will deliver their young.
The second stage of labor consists of the delivery of the newborn. This is accomplished by a combination of strong uterine and abdominal muscle contractions. The dam typically lies down and strains in a rhythmic pattern of contractions that gradually become stronger and closer together. The amniotic and allantoic sacs of the placenta (afterbirth) usually rupture before the actual delivery of the newborn.
The third stage of labor is the delivery of the placenta. The placenta separates from the wall of the uterus and is expelled by weaker uterine contractions. The dam often eats the placenta or placentas. In multiparous species, such as the dog, cat, and pig, the second and third stages of parturition intermix with one another. Typically newborns and placentas are delivered alternately; that is, after a newborn is delivered, its placenta is usually expelled before the next newborn is delivered.
why is it important that uterine contractions continue after the fetus and placenta have been delivered?
Uterine contractions continue so that involution can occur. The contractions cause the sloughed endometrium to be expelled so that the sites where the placenta was attached can heal. Pressure from the continued uterine contractions usually stops bleeding relatively quickly.
why does masititis in 1 quarter of a dairy cow's udder not necessarily spread to the other 3 quarters?
Each quarter is a completely separate unit from the other three, with its own milk-secreting systems and ducts leading down to their own teats. Infection does not directly spread from one quarter to another. It has to spread down through the teat and duct system of one quarter and up another, or, on rare occasions, it can spread systemically (through the bloodstream).
Describe the suspensory apparatus of the udder.
This suspensory apparatus of the udder consists of a slinglike arrangement of ligaments that runs down the center and around the sides of the udder. The medial suspensory ligament contains many elastic fibers that allow it to stretch. It passes down the center between the left and right halves of the udder. The lateral suspensory ligaments are composed largely of strong, but relatively inelastic, collagen fibers. They pass down and around the lateral sides of each half of the udder. The strong lateral ligaments provide firm support for the udder, and the elastic medial ligament acts as a shock absorber for the udder as the animal moves around.
Why don't the mammary glands of male animals usually develop or secrete milk?
Males' mammary glands don't develop and secrete milk because they do not have the balance of hormones required.
describe the importance of colostrum to the health of a newborn animal.
. Before producing actual milk, the mammary gland produces colostrum, which contains larger amounts of proteins, lipids, and amino acids than milk and also contains high levels of various essential vitamins. Colostrum supplies important nutrients to the newborn and has a laxative effect that helps clear the dark, sticky meconium from the newborn's intestinal tract. In addition, colostrum provides antibodies that provide passive immunity for the newborn. These antibodies are specific for disease-causing organisms that the dam has been exposed to or vaccinated against. If the newborn drinks sufficient colostrum during the first few hours after birth, the large antibody molecules will be absorbed intact into its bloodstream and defend the animal against specific diseases. If colostrum is not consumed within the first few hours, the lining of the newborn's intestine can no longer absorb the large antibody molecules intact. They will be broken down by the digestive process, and passive immunity will not be transmitted. These animals may die of early infections, or they may be weaker and not grow as rapidly as animals that consume colostrum at the appropriate time.
describe how nursing or milking causes milk let down and also helps sustain lactation.
When milk is produced, it accumulates up high in the mammary gland in the alveoli and small ducts. It does not move down into the larger ducts and sinuses, where it is accessible for nursing or milking, until milk letdown occurs. Continued physical stimulation of the teat or nipple and regular removal of milk from the gland send sensory nerve impulses to the brain. From there nerve pathways lead to the hypothalamus, which stimulates the anterior pituitary gland to continue its production of the hormones that keep lactation going. It also causes the hypothalamus to release the hormone oxytocin from the posterior pituitary gland. Oxytocin travels to the mammary gland and causes musclelike myoepithelial cells around the alveoli and small ducts to contract. This squeezes milk down into the large ducts and sinuses, where it can be removed by nursing or milking. When nursing or milking stops, the flow of essential hormones stops also. The lack of hormonal stimulation combined with increased pressure in the gland (because it is no longer being emptied) causes lactation to gradually cease and the mammary gland to dry up. This is called involution of the mammary gland.
openings through which amphibian species filter blood and coelomic fluid
funnel-shaped dilated structure of the kidney that transports urine into the ureter
a collection of capillaries in the kidney into which waste products are filtered
basic functional unit of the kidney composed of a renal tubule and corpuscle
provides temp control in the testes by supplying blood to the testes that is cooler than internal bodily blood
A structure in male dogs formed by the corpus spongiosum and becomes engorged with blood during mating, preventing withdrawal of the penis until several minutes after completion of copulation
the time from 1 heat period to the next
a broad ligament portion that contains ovarian blood vessels to make up the ovarian pedicle
Changes in mammalian sperm once in the female genital tract that allow the sperm to penetrate the zona pellucida for fertilization of the oocyte
The hollow structure formed during early embryonic development containing the inner cell mass that gives rise to the embryo
located in the umbilical cord and serves as the drainage tube from the fetal urinary bladder
Lobule-like placental attachments on the surface of the placenta that join with caruncles in the lining of the uterus of ruminants
Egg laying mammals
the process that returns the uterus to its nonpregnant size after parturition