PCOM: Anatomy 2 - midterm set - digestive, blood, and cardiovascular systems
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Created by:
plecke Plus on February 23, 2012
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470 terms
Terms | Definitions |
|---|---|
 the three layers of the blood vessel walls, internal to external | tunica intima, tunica media, tunica externa |
| three layers of the tunica intima, internal to external | endothelium, sub-endothelial layer, internal elastic lamina |
| function of the tunica intima | reduces friction between the vessel walls and the blood |
| layer of the tunica intima that is not found in veins | internal elastic lamina |
| the basal membrane of the blood vessels | the sub-endothelial layer |
| function of the internal elastic lamina | elasticity for arteries due to arterial pressure (high pressure system) |
| composition of the tunica media | smooth and elastic muscles and the external elastic lamina |
| differences in the tunica media in arteries and veins | thinner in veins as it is a low pressure system |
| two layers of the tunica media in arteries | muscle layer and the external elastic lamina |
| function of the tunica media | controls vasodilation and vasoconstriction |
| composition of the tunica externa | collagen fibers |
| function of the tunica externa | protects, reenforces, and anchors the vessel to surrounding structures |
| feature of vessel structure found in veins only | internal, one way venous valves that are covered in endothelium |
| function of the venous valves | to prevent back flow of blood as it returns to the heart - found mostly in the extremities |
| how blood returns to the heart against gravity | the muscles of the leg pump it up as constricting occurs during use (e.g. walking) |
| how blood form the abdominopelvic region returns to the heart | the respiratory pump - contraction of the diaphragm creates high pressure in the lower region and low pressure in the upper region, causing blood to be drawn upward |
| the largest arteries as they lead away from the heart | elastic or conducting arteries |
| physical characteristic of conducting arteries allowing them to withstand changes in arterial pressure due to the heart action | contain large amounts of elastin, creating elasticity |
| second level of arteries | muscular or distributing arteries |
| function of muscular or distributing arteries | deliver blood to specific organs and very active in vasoconstriction |
| important physical characteristic of muscular or distributing arteries | they contain the largest tunica media of all arteries due to greater muscle content for vasoconstriction |
| smallest arteries | arterioles |
| function of the arterioles | regulate blood flow into the capillary beds through vasoconstriction and vasodilation |
| important physical characteristic of arterioles | the muscle layer of the tunica media is made of smooth muscle only |
| physical characteristic of the capillaries | they are the smallest vessels |
| function of the capillaries | they allow the exchange of substances between the vessels and the interstitial fluid |
| continuous capillaries | contain no muscle, the capillary wall is one cell thick with a basement membrane, and are the least permeable and most common capillary; still allow the passage of fluids and small solutes |
| fenestrated capillaries | contain fenestrations (small pores) and are more permeable than continuous capillaries and are found in specialized locations like the kidneys and small intestine |
| sinusoidal capillaries | the most permeable capillaries allowing large molecules to pass through; found in the liver, spleen and bone marrow |
| where the smallest capillaries are found | in the spleen - sinusoidal |
| structure at the end of the arterial circulation | capillary beds |
| structure of the capillary beds | microcirculatory network with a vascular shunt and the true capillaries that act as exchange vessels |
| structure at the entry point for the capillary beds | pre-capillary sphincter |
| function of the pre-capillary sphincter | regulates the flow of blood through the capillary bed |
| structure of the pre-capillary sphincter | a cuff of smooth muscle surrounding each capillary at the metarteriole |
| blood flow when the pre-capillary sphincter is open | blood flows into the capillary bed allowing the plasma to leave the blood into the interstitial spaces with nutrients, etc for the tissues/cells they supply |
| blood flow when the pre-capillary sphincters are closed | blood passes through the vascular shunt, bypassing the capillary bed without release plasma and its solutes |
| where the plasma released into the interstitial fluids returns to the blood | in the venous side of the capillary bed - the beginning of venous system |
| percentage of plasma that is not returned to the blood by capillary re-uptake | 1% |
| where the capillaries converge | venules - allow fluid and WBCs to move easily between the blood and tissues |
| what venules form as they converge | veins |
| physical characteristics of veins | thin walled with relatively large lumens |
| additional term for small and large veins | capacitance vessels |
| function of veins as capacitance vessels | store blood - 65% of the blood in the body is in the venous system at any given time |
| venous response when blood pressure drops | vasoconstriction - increases the blood volume in the arterial system |
| percentage of blood in systemic circulation at any given time | 84% |
| vascular anastomoses | where vascular channels unite forming alternative blood pathways to allow blood supply and drainage from an area even if one channel is blocked |
| blood pressure | measured in arteries - the force per unit area exerted by the blood on the blood walls expressed in millimeters of mercury |
| effect of High Blood Pressure | damages the endothelium of the vessels leading to atherosclerosis |
| how blood pressure results | the resistance of the blood during the pumping action of t heart |
| blood pressure levels throughout the systemic circuit | highest in the aorta, decreasing throughout the pathway until is reaches 0 in the right atrium |
| cardiac output | the amount of blood ejected from the ventricle each minute CO = SV (stroke volume) x HR (heart rate) |
| stroke volume | the amount of blood ejected by the ventricle on each contraction |
| what arterial Blood pressure signifies | how much the arteries close to the heart can be stretched (compliance or distensibility) and the volume of blood forced into them at any given time |
| systolic pressure | the peak pressure created when the left ventricle contracts forcing blood into the aorta (normally about 120mm Hg) |
| diastolic pressure | the pressure created when back flow into the ventricles is prevented by the semilunar valves (normally about 70-80 mm Hg) |
| characteristics of where arteries run | deep and are well protected |
| characteristics of where veins run | both deep (parallel to the arteries) and superficial (just under the skin |
| number of terminal systemic arteries | one - the aorta |
| number of terminal systemic veins | two - inferior and superior vena cava |
| three parts of the aorta | ascending aorta, arch of the aorta, thoracic aorta |
| the 4 paired arteries of the head and neck | costocervical trunk, thyrocervical trunk, vertebral artery, common carotid artery |
| from where the left common carotid artery arises | from the aortic arch |
| from where the right common carotid arises | from the brachiocephalic trunk as it branches from the aortic arch |
| two branches of the common carotid | the external and internal |
| area the internal carotid supplies | major supplier of blood to the brain |
| area the external carotid supplies | the scalp, face, larynx and some of the thyroid |
| from where the vertebral arteries arise | subclavian artery, the first and most medial branch |
| area the vertebral artery supplies | passes through the transverse processes of the cervical spine and supplies the brain |
| from where the thyrocervical artery arises | subclavian artery, lateral to the vertebral arteries |
| area the thyrocervical trunk supplies | thyroid gland and portions of the cervical spine |
| from where the costocervical artery arises | subclavian artery, lateral to the thyrocervical arteries |
| area the costocervical artery supplies | deep neck muscles |
| the three branches of the aortic arch from right to left | the brachiocephalic trunk, the left common carotid, the left subclavian |
| the two branches of the brachiocephalic trunk medial to lateral | the right common carotid, the right subclavian |
| area supplied by the subclavian arteries | the upper extremities |
| pathway of the subclavian arteries | becomes the axillary artery at the armpit, the brachial artery at the elbow and the radial and ulnar arteries at the wrist |
| from where the left and right coronary arteries arise | the ascending aorta |
| artery that supplies the abdomen | the abdominal aorta |
| from the where the abdominal aorta arises | from the thoracic aorta as it passes through the aortic hiatus in the diaphragm |
| most proximal artery that supplies the lever, stomach and spleen | celiac trunk |
| artery that supplies intestines, rectum and tissues | superior and inferior mesenteric arteries |
| from where the mesenteric arteries arise | the abdominal aorta |
| artery that supplies the kidneys | the renal artery |
| from where the renal arteries arise | between the superior and inferior mesenteric arteries off the abdominal aorta |
| arteries that supply the pelvis and lower extremities | the common iliac arteries |
| from where the common iliac arteries arise | the abdominal artery bifurcates at around the iliac crest/L-4 level, forming the right and left common iliac arteries |
| how blood supply moves to the pelvis | the common iliac bifurcates and the pelvis and pelvic organs are supplied by the internal iliac artery |
| how blood supply moves to the lower extremities | the common iliac bifurcates and the external iliac artery supplies the lower extermities |
| pathway of the external iliac arteries | becomes the femoral artery in the thigh, has multiple branches at the knee |
| area from which blood drains to the superior vena cava | head, neck, upper extermities |
| area from which blood drains to the inferior vena cava | the trunk and lower extremities |
| area from which blood drains to the coronary sinus | the heart |
| three pairs of veins to which blood drains from the head and neck | external jugular, vertebral, and internal jugular |
| area from which blood drains to the external jugular | scalp and face |
| area from which blood drains to the vertebral veins | the brain |
| area from which blood drains to the internal jugular | the brain |
| the area to which the external vein drains | the subclavian vein |
| area to which the subclavian, vertebral and internal jugular drain | the brachiocephalic branch bilaterally |
| area to which the brachiocephalic veins drain | the merge and become the superior vena cava |
| pathway by which the blood of the thoracic wall and tissues are drained | the accessory hemi-azygos veins to the hemi-azygos veins, which merge to the azygos vein which drains to the superior vena cava |
| pathway by which the abdominal viscera and abdominal walls drain | through the portal system - the splenic vein drains the spleen and merges with the superior mesenteric vein to become the hepatic portal vein which transports blood to the two lobes of the liver for the storage of unused nutrients which then drains the blood to the inferior vena cava via the Right and left hepatic veins |
| to where the inferior mesenteric circulation drains | to the splenic vein |
| pathway by which the blood drains from the pelvis and pelvic organs | via the internal iliac vein which merges with the external iliac vein to form the common iliac vein to the inferior vena cava |
| pathway by which the blood drains from the lower extremities | lower limbs via several veins to the femoral vein in th thigh to the external iliac vein which merges with the internal iliac vein to form the common iliac vein which feed to the inferior vena cava |
| function of the lymph system | takes up the 1% of the plasma that is not reabsorbed by the venus capillaries in the capillary beds during circulation and cleans it |
| flow of the lymphatic system | one way to the heart |
| beginning of the lymph system | lymph capillaries between the tissue cells and the blood capillaries in the loose CT - these are blind ends (not circular) |
| to where the lymph capillaries feed | to the lymph collecting vessels |
| to where the lymph collecting vessels feed | to the lymph trunks |
| to where the lymph trunks feed | the lymph trunks drain large areas of the body and feed to the thoracic duct and the right lymphatic duct |
| lymph nodes | collections of WBCs along the lymph collecting vessels and lymph ducts that clean the plasma |
| areas drained by the right lymphatic duct | head, neck, right trunk and the right upper extremities |
| pathway of the right lymphatic duct | drains to the right subclavian vein |
| areas drained by the thoracic duct | the majority of the lymph system, excluding the head, neck, right trunk, and right upper extremities |
| size and weight of the heart | fist sized; about 250-300g |
| location of the heart | mediastinum 2/3 lies left of the mid-sternal line |
| orientation of the top of the heart | the base of the heart points to the right shoulder |
| orientation of the bottom of the heart | the apex points toward the left hip |
| the covering of the heart | double layered pericardium |
| outer layer of the pericardium | loose fibrous pericardium |
| make-up of the fibrous pericardium | dense CT |
| function of the fibrous pericardium | protects and anchors the heart |
| inner layer of the pericardium | serous pericardium |
| make-up of the serous pericardium | thin, slippery two layered serous membrane |
| two layers of the serous membrane | parietal pericardium and visceral pericardium or epicardium |
| location of the parietal pericardium | lines the inside of the fibrous pericardium |
| location of the epicardium | covers the surface of the heart |
| area between the parietal pericardium and epicardium | pericardial cavity |
| structure of the pericardial cavity | filled with serous fluid |
| function of the serous fluid in the pericardial cavity | to provide lubrication for the serous membranes to allow smooth movement during contraction and relaxation of the heart |
| three layers of the heart wall outer to inner | epicardium, myocardium, endocardium |
| structure of the epicardium | serous membrane lining the outer wall of the heart |
| structure of the myocardium | composed mainly of cardiac muscle and forms the bulk of the heart |
| endocardium | epithelial inner layer of the heart wall lining the chambers and valves of the heart |
| function of the endocardium | blood comes into contact with endocardium and enters the tissue |
| functions of the right atrium | receives the blood venous blood returning from the body through three veins |
| characteristic of venous blood | low oxygen content |
| three veins entering the right atrium | superior vena cava, inferior vena cava, coronary sinus |
| function of the superior vena cava | returns blood from the head, neck and upper extremities |
| function of the inferior vena cava | returns blood from the trunk and lower extremities |
| function of the coronary sinus | all veins from the heart drain into the coronary sinus which drains the coronary blood back to the right atrium |
| two networks in the heart | upper and lower |
| upper network of the heart | R & L atria |
| lower network of the heart | R & L Ventricles |
| how the upper and lower network interact | when one is performing a function, the other is doing the opposite |
| where the blood goes from the R atrium | passes to the right ventricle passing the tricuspid valve |
| function of the tricuspid valve | prevents back flow of blood from the right ventricle to the right atrium; closes when the ventricles contract and opens when they relax |
| functions of the right ventricle | pumps blood to the pulmonary trunk via the pulmonary valve |
| function of the pulmonary valve | to prevent back flow of blood from the pulmonary trunk to the right ventricle; opens when the right ventricle contracts and closes when blood fills the cusps in the valve, forcing it closed |
| name for blood circulation from the heart to lungs and back | pulmonary circulation |
| structure of the pulmonary trunk | bifurcates into the left and right pulmonary arteries |
| characteristics of the pulmonary arteries | only arterial flow in the body with low-oxygenated blood; bilateral set (2) |
| functions of the left atrium | receives oxygenated blood from the lungs via the pulmonary veins |
| characteristics of the pulmonary veins | only venous flow in the body with highly oxygenated blood; bilateral paired veins (4) |
| where the blood goes from the left atrium | passes to the left ventricle through the bicuspid or mitral valve |
| function of the mitral valve | prevents back flow from the left ventricle to the left atrium; closes when the ventricle contracts and opens when the ventricle relaxes |
| function of the left ventricle | pumps blood to the aorta via the aortic valve |
| function of the aortic valve | prevents back flow from the aorta to the left ventricle; closes when blood fills the cusps in the valve, forcing it closed |
| name of the blood circuit from the heart to the lungs and back | pulmonary circuit |
| name of the blood circuit from the heart to the body and back | systemic circuit |
| physical characteristic of the left ventricle | more muscle because it pumps blood into the high pressure systemic circuit |
| physical characteristic of the right ventricle | less muscle as it pumps blood into the low pressure pulmonary circuit |
| name for the aortic and pulmonary valves | semilunar valves |
| name for the tricuspid and bicuspid valves | atrioventricular valves |
| name of the tendons anchoring the AV valves in place | chordae tenidinae |
| function of the chordae tendonae | prevent the AV valves from opening the wrong way |
| how blood is pumped through the heart | the right side pumps blood into the pulmonary circuit and the left side simultaneously pumps blood into the systemic circuit |
| what provides blood supply to the heart | the coronary circulation |
| why separate blood supply necessary for the heart | because no nutrients pass from the blood as it passes through the chambers of the heart |
| from where the right and left coronary arteries arise | ascending aorta |
| path of the left coronary artery | bifurcates into the circumflex artery and the anterior inter-ventricular artery |
| to what part of the heart the circumflex artery supplies blood | the left atrium |
| to what part of the heart the anterior inter-ventricular artery supplies blood | the anterior ventricles |
| the path of the circumflex and anterior inter-vertricular arteries | from the left coronary artery then to the apex of the heart where it merges with the right coronary artery and supplies the right atrium and ventricle |
| path of the right coronary artery | branches at the right marginal artery and continues and branches at the posterior inter-ventricular artery then passes to the apex of the heart where it merges with the circumflex and anterior inter-ventricular arteries and supplies the right atrium and ventricle |
| to what part of the heart the right marginal artery supplies blood | to the anterior right ventricle |
| to what part of the heart the posterior inter-ventricular artery supplies blood | the posterior ventricles |
| to where blood from the heart drains | cardiac viens |
| where the cardiac veins drain | to the coronary sinus |
| coronary artery in which blockage is likely to lead to heart attack | left coronary artery or left inter-ventricular artery |
| what is the cause of myocardial infarction | blockage in the coronary arteries - particularly the left or left inter-ventricular |
| a sign that the AV valves in the heart are not closing all the way or may be damaged | murmur |
| structure of cardiac muscle | striated, skeletal muscle |
| mechanics of contraction of cardiac muscle | sliding filament method |
| characteristics of cardiac muscle cells | short, fat, branched and interconnected by intercalated discs |
| how some cardiac muscle cells are stimulated | self-stimulated |
| how the heart contracts | all or none - it does not contract by individual motor units |
| significance of the cardiac muscles' refractory period | longer than skeletal muscle (250 ms vs 1-2 ms) to prevent tectonic contractions |
| importance of O2 supply to the heart | the heart relies on aerobic respiration |
| nutrient supply in the heart | the heart is capable of switching metabolic pathways to use whatever nutrient supply is available |
| relative importance of nutrient vs O2 supply in the heart | O2 more critical due to the heart's need to function aerobically and its metabolic flexibility |
| autorhythmicity | the myocardium is the contractile muscle, however a portion is specialized to create electronic impulses to stimulate contraction |
| percentage of specialized myocardium that initiates and transmits electrical impulses throughout the heart | 1% |
| where the electrical impulse initiate in the heart | the sino-atrial (SA) node |
| where the electrical impulse goes from the SA node | concurrently to the atria and the atrio-ventricular node (AV node) |
| where the SA and AV node are located | the right atrium |
| which are the most important chambers of the heart | the ventricles as they are responsible for the pumping of blood |
| how the ventricles are stimulated to contract and pump blood | electrical impulses from the SA and AV nodes |
| where the impulse from the AV node travels | the Bundle of His |
| location of the Bundle of His | in the inter-ventricular septum which divides the ventricles |
| where the impulse from the Bundle of His travels | branches into the Right and Left Bundle Branches |
| where the impulse travels from the Right and Left Bundle Branches | to the Purkinje Fibers |
| pathway of the Purkinje fibers | down the inter-ventricular septum to the apex of the heart, then upward to the walls of the ventricles; these go right into the papillary muscles |
| structure of the intrinsic conduction system | specialized cardiac muscle cells that initiate and distribute impulses ensuring orderly electrical impulses in the heart |
| complete chain of impulses in the heart | SA node, AV node, Bundle of His, Right and Left Bundle Branches, Purkinje Fibers |
| electrical characteristic of the SA node | unstable resting potential which generates the electrical impulse of the heart |
| name of the unstable resting potential in the SA node | pacemaker potential |
| interaction of the autonomic nervous system with the heartbeat | the sympathetic system speeds up and deepens contractions, and the parasympathetic slows them down |
| function of an electrocardiograph | monitors and records the electrical signals of the heart and records them |
| how the electrical signals of the heart are recorded | as an electrocardiogram (ECG or EKG) |
| contracting phase of the heart | systole |
| relaxing/filling phase of the heart | diastole |
| coordination of the atria and ventricles in contraction | the upper and lower networks act in unison - atria contract together and the ventricles contract together |
| term for the atria contraction | atrial systole |
| term for ventricular relaxation/filling | ventricular diastole |
| term for the ventricles contracting | ventricular systole |
| term for the atria relaxing/filling | atrial diastole |
| S1 | the first heart sound "lub" - it is the sound of the AV valves closing at ventricular systole |
| S2 | the second heart sound "dub"- the sound of the semilunar valves closing after the pressure has built in the aorta and pulmonary trunk and the cusps fill, closing the semilunar valves during ventricular diastole |
| how blood moves from the atria to the ventricles | after contraction, 75% of the blood falls into the ventricles after which the atria contract slightly to pump the rest into the ventricles - atrial systole |
| what causes a murmur | the turbulent back flow of blood through a valve that does not close tightly |
| term for the contractile phase of the cardiac cycle | systole |
| term for the relaxation phase of the cardiac cycle | diastole |
| definition of the cardiac cycle | the series of pressure and volume changes in the heart during one heartbeat |
| ventricular filling | during mid to late ventricular diastole - AV valves open, SL valves closed and blood flow passively from atria to ventricles; end of ventricular diastole the atria contract (atrial systole) and push the last of the blood into the ventricles |
| phase in the cardiac cycle during which blood is pumped into the pulmonary trunk and aorta | ventricular systole - the atria relax (atrial diastole) and the ventricles contract (ventricular systole), closing the AV vlaves and opening the SL valves |
| what causes the SL valves to close and the AV valves to open | isovolumetric relaxation - during early ventricular diastole the ventricular pressure drops |
| cardiac output | the amount of blood pumped out of the ventricle per minute |
| how cardiac output is calculated | the product of stroke volume and heart rate |
| equation for cardiac output | CO = SV x HR |
| Classification of blood | Blood is a specialized form of CT |
| what makes blood a type of CT | composed of living cells, or formal elements, suspended in a non-living matrix (fluid) |
| The fluid matrix of blood | plasma |
| Three components of blood | RBC, WBC, platelets |
| the three layers of centrifuged blood (top to bottom) | Plasma, buffy coat, erythrocytes |
| characteristics of erythrocytes | RBC's - heaviest and most numerous and dense element |
| %age of whole blood that is erythrocytes | 45% |
| what the %age of erythrocytes in blood is called | hematocrit - normal range 36%-50% |
| characteristics of the buffy coat | leukocytes (WBC's) and platelets - smallest element |
| %age of whole blood that is Leukocytes | <1% |
| critical function of platelets | clotting |
| the pH range of blood | slightly basic - 7.35-7.45 |
| density and viscosity of blood | slightly higher than water |
| why pH is so important to blood | critical enzymes don't function out of the 7.35-7.45 pH range |
| volume of blood | 5-6 liters in males and 4-5 liters for women |
| functions of blood | distribution, body regulation, and protection |
| distribution function of blood | oxygen, nutrients, elimination of wastes, distribution of endocrine hormones |
| method of oxygen distribution by the blood | from the lungs via RBC |
| method of nutrient distribution | from the GI tract via plasma |
| method of elimination of wastes distribution | via plasma to the lungs for gas and to the kidneys for nitrogenous wastes |
| method of endocrine hormone distribution | via the plasma to various parts of the body |
| regulation function of blood | body temperature, pH balance, and fluid volume |
| method of body temperature regulation | absorption and distributing heat to the body and skin surface |
| method of pH balance | blood proteins and solutes help maintain pH of system |
| method of fluid volume regulation | water homeostasis vis salts and blood proteins in the plasma |
| protection function of blood | protects against excessive blood loss via clotting and the immune system |
| clotting element of blood protective function | platelets are one key element |
| immune system | leukocytes protect the body from infection |
| characteristics of blood plasma | sticky, straw colored fluid 90% water, the rest is solutes - nutrients, gases, hormones, wastes, products of cell activity, ions, and proteins |
| plasma protein content | 8% of plasma |
| largest protein component of blood | 60% albumin |
| functions of albumin | many hormones are carried by albumin and it is responsible for osmotic pressure in blood |
| where albumin is produced | liver |
| what poor osmotic pressure in blood causes | leaking fluids leading to edema |
| characteristics of erythrocytes (RBC's) | small, biconcave, lack nuclei and most organelles - mostly contain hemoglobin |
| function of hemoglobin | oxygen binding pigment responsible for transporting most of the O2 in blood |
| structure of hemoglobin | globin protein bound to the heme pigment |
| structure of heme | iron centric surrounded by N |
| number of hemes in each RBC | 4 |
| globin structure | 4 polypeptides attached to heme via shared N |
| types of poly peptides in globin | 2 - alpha and beta |
| number of globins in each RBC | 4 total in 2 sets - 2 alphas and 2 betas |
| where O2 binds in hemoglobin | to the hemes - up to 4 O2 |
| percentage of saturation in blood | 1 through 4 O2 molecules per RBC = 25% to 100% |
| lifespan of a healthy RBC | 120 days |
| where dead RBC's are "recycled" | spleen |
| where excess iron is stored if not needed to form hemes | liver |
| how iron is stored in the liver | bound to ferritin |
| what is produced in the spleen when iron is removed from the RBC | non-iron heme |
| how non-iron heme is processed | in the spleen it is converted to biliverdin then to bilirubin and transported to the liver where it is converted into bile and stored |
| condition caused by excess bilirubin in the system | jaundice |
| term for blood cell formation | hematopoeisis |
| where hematopoeisis occurs | in the bone marrow |
| term for the formation of RBC's | erythropoeisis |
| process of erythropoeisis | hemocytoblast becomes a myeloid stem cell becomes a proerythroblast which then develops into a mature RBC |
| last stage of erythropoeisis in the marrow | reticulocyte - when the nucleus is ejected from the developing RBC |
| what happens when the reticulocyte is formed | it leaves the marrow and becomes a an erythrocyte in 12-24 hours after leaving the marrow |
| normal range of reticulocyte count in the blood | .5-1% |
| what a high reticulocyte count may indicate | excessive hemolysis |
| what controls erythrocyte production | erythropoietin |
| how blood O2 level homeostasis is achieved | when O2 levels in the blood drop, blood cells are produced |
| erythropoietic mechanism | O2 levels drop due to decreased RBC, hemoglobin or O2 supply; Kidney (and liver) produce erythropoietin; erythropoietin stimulates hemocytoblast differentiation in the marrow; RBC count increases; O2 in the blood increases with more healthy RBC's |
| dietary requirements for RBC production | iron, B12, folic acid, proteins, lipids, and carbohydrates |
| how iron is processed in erythropoiesis | stored in liver as ferritin and hemosiderin; transported loosely bound to transferrin |
| how B12 and folic acid is used in erythropoiesis | necessary for the DNA synthesis in cell division |
| erythrocyte disorders | anemia - RBC deficiency; polycythemia - RBC excess; sickle cell - misshaped RBC's due to an amino acid substitution in the DNA |
| distinctive fact of leukocytes | only formed element in blood that are complete cells and makeup <1% of blood volume |
| role of leukocytes | immune system - critical for fighting disease |
| categories of leukocytes | phagocytes and lymphocytes |
| characteristic of granulocytes | large cells, lobed nuclei, phagocytic, stain with granule appearance |
| three type of granulocytes | neutrophils, eosinophils, basophils |
| function of neutrophils | most numerous leukocyte, attracted to inflammation sites and are actively phagocytic |
| function of eosinophils | uncommon and attack parasites |
| function of basophils | least numerous leukocyte and release histamines in the inflammatory response |
| characteristics of agranulocytes | lymphocytes that lack visibly staining granules |
| types of lymphocytes | monocytes, B-lymphocytes, and T-lymphocytes |
| function of T-cells | directly attack virus infected and tumor cells |
| function of B-cells | become plasma cell when in contact with pathogen; plasma cells secrete antibodies -immunoglobulins |
| function of monocytes | become macrophages and activate T-Cells |
| T-cell production | immature cells are sent from bone marrow to the thymus gland and are exposed to foreign and self antigens; those that respond to self-antigens are destroyed others are released into the blood |
| term for the formation of WBC's | leukopoiesis |
| how leukopoiesis is regulated | by the production of interleukins and colony-stimulating factors |
| process of leukopoiesis | hemocytoblasts are differentiated along two pathways: lymphoid and myeloid stem cells |
| cells produced on the lymphoid stem cell path | lymphocytes (T-cells and B-Cells) |
| cells produced on the myeloid stem cell path | granulocytes and monocytes |
| pathology of Leukocytes | high count= leukocytosis; low count=leukopenia; = |
| production of unspecialized WBC that divide cancerously | leukemia |
| cause of infectious mononucleosis | Epstein-Barr virus |
| term for the buildup of cancerous cells | SOL - space occupying lesion |
| characteristic of platelets | not complete cells |
| formation of platelets | fragment of megakaryocytes formed by the repeated mitosis without cytokinesis |
| function of platelets | critical to clotting by forming a temporary seal when a vessel is broken |
| treatment for substantial blood loss or thrombocytopenia | whole blood transfusion |
| treatment for low blood volume | plasma and blood volume expander are given |
| term for antigens on the cell walls of RBC's | agglutinogens |
| term for preformed antibodies in the plasma | agglutinins |
| characteristics of AB blood type | has both A and B agglutinogens, but no agglutinins |
| Characteristics of A blood type | has A agglutinogens, and B agglutinins |
| characteristics of B blood type | has B agglutinogens and A agglutinins |
| characteristics of O blood type | no agglutinogens and A and B agglutinins |
| how a transfusion reaction occurs | the donors blood is attacked by the recipient's agglutinins (antibodies) |
| what happens in a transfusion reaction | the agglutinins cause agglutination (clumping of the foreign cells) and hemolysis of the foreign cells occurs |
| Rh factor | the presence (+) or absence (-) of a group of RBC antigens |
| where RH factor received its name | Rhesus monkeys |
| two main groups of the organs of the digestive system | alimentary canal and accessory organs |
| another term for the alimentary canal | gastro intestinal tract (GI tract) |
| the alimentary canal | the continuous muscular digestive tube that winds through the body |
| organs of the alimentary canal | mouth, pharynx, esophagus, stomach, small intestine, large intestine |
| function of accessory organs | aid digestion physically and produce secretion to breakdown foodstuff in the GI tract |
| the accessory organs | teeth, tongue, gallbladder, salivary glands, liver, pancreas |
| definition of the digestive process | the ingestion, breakdown and absorption of macronutrients |
| macronutrients | fat, protein, carbohydrates |
| elements of the digestive process | ingestion, propulsion, mechanical digestion, chemical digestion, absorption, defecation |
| definition of ingestion | the act of putting food in your mouth |
| definition of propulsion | the motility/movement of food through the GI tract |
| two elements of propulsion | swallowing, peristalsis |
| definition of mechanical digestion | the physical process of preparing the food for chemical digestion |
| the four elements of mechanical digestion | chewing, mixing, churning, and segmentation |
| definition of chemical digestion | a series of catabolic steps in which complex food molecules are broken down to their chemical building blocks by enzymes |
| definition of absorption | the passage of digested end products from the lumen of the GI tract through the mucosal cells into the blood or lymph |
| where the macronutrients are absorbed | proteins and carbs to the blood and fats to the lymph |
| definition of defecation | the elimination of indigestible substances from the body via the anus as feces |
| the sole purpose of the digestive system | to optimize digestion |
| how the sole purpose of digestion differs from other organ systems | other organ systems are designed to maintain levels of substances in the blood |
| how digestive activity is triggered | mechanical and chemical stimuli |
| process of mechanical stimulation of the GI tract | sensors detect distention |
| process of chemical stimulation of the GI tract | sensors detect chemicals in the GI tract - i.e. the presence of fat, proteins, and glucose |
| two types of controls of the Digestive system | intrinsic and extrinsic |
| intrinsic controls of the DS | hormones - some enhance and some impair the DS |
| extrinsic controls of the DS | nervous system control - parasympathetic system, i.e. rest & digest |
| what covers the external surface of most of the digestive organs | visceral peritoneum |
| what lines the wall of the abdomino-pelvic cavity | parietal peritoneum |
| what lies between the visceral and parietal peritoneums | peritoneal cavity |
| what fills the peritoneal cavity | serous fluid |
| composition of the mesentery | double layer of peritoneum that extends from the body wall to surround the digestive organs |
| functions of the mesentery | allows blood vessels, lymphatics, and nerves to reach the digestive organs; holds the organs in place; stores fat |
| how the mesentery is formed | a double layered fold of the parietal peritoneum extends from the posterior body wall, forming the mesentery until it becomes the visceral peritoneum as it surrounds the digestive organs |
| the five different mesenteries | mesentery proper, mesocolon, greater omentum, lesser omentum, falciform ligament |
| mesentery proper | runs from the posterior abdominal wall to the SI and covers the SI |
| mesocolon | runs from the posterior abdominal wall to the LI and covers the LI |
| greater omentum | an apron of mesentery arising from the visceral peritoneum of the stomach at the greater curvature and running to cover the small intestine, the spleen and transverse LI where it attaches to the mesocolon |
| lesser omentum | mesentery arising from the visceral peritoneum of the liver and running to the lesser curvature of the stomach |
| falciform ligament | mesentery arising from the anterior abdominal wall attaching to the liver, separating the right and left lobes anteriorly and suspending the liver from the diaphragm |
| retroperitoneal organs | organs that lie posterior to the mesentery on the dorsal abdominal wall |
| how organs became retroperitoneal | moved outside of the mesentery during embryonic development |
| the retroperitoneal organs | duodenum, pancreas, ascending colon, descending colon, rectum |
| splanchnic circulation | the arterial supply of the DS branching from the abdominal aorta and the hepatic portal circulation |
| hepatic portal circulation | the venous portion of the splanchnic circulation carrying nutrient rich blood from the digestive organs to the liver |
| four layers of the tissue of the alimentary canal | mucosa, submucosa, muscularis externa, serosa |
| mucosa | innermost, moist epithelial membrane lining the entire GI tract |
| functions of the mucosa (3) | secretes mucus, digestive enzymes and hormones; absorbs digestive end products into the blood; protects against infectious disease |
| 3 layers of the mucosa | epithelium, lamina propria, muscularis mucosa |
| composition and function of the mucosal epithelium | simple columnar epithelial tissue that secretes mucous protecting the organs from the digestive process |
| composition and function of the lamina propria | loose areolar CT that houses pockets of MALT - mucosa associated lymphatic tissue - that help defend against infectious disease |
| Peyer's patches | areas of MALT in the mucosa that extend to the submucosa |
| composition and function of the muscularis mucosa | smooth muscle that produces local movement in the mucosa and, in a constant state of tone, creates the folds of the mucosa to increase surface area for absorption |
| composition the submucosa | areolar CT with elasticity that allow the GI tact to expand and contract; contains lymph vessels and lymphoid follicle and is highly vascularized, providing blood supply for surrounding tissue layers |
| meissner's plexus | network of nerve fibers in the submucosa - aka submucosal nerve plexus - that helps control secretions |
| two levels of the muscularis externa | inner, circular layer of muscle and an outer, longitudinal layer of muscle |
| function of the muscularis externa | movement by contraction; thickens to sphincters incrementally along the GIT to prevent backflow |
| myenteric plexus | nerve network in the muscularis externa that is responsible for movement |
| composition of the serosa | the visceral peritoneum surrounding the AC - areolar CT lined with the mesothelium - simple squamous epithelial cells |
| nervous supply of the alimentary canal | supplied by enteric neurons that connect to the two plexuses of the AC; this intrinsic nervous supply is enhanced extrinsically by the parasympathetic nervous response |
| composition of the mouth | a stratified squamous epithelial mucosa lined cavity bound by the lips, cheeks, palate and tongue |
| composition and function of the lips and cheeks | skeletal muscle covered by skin that functions to keep food between the teeth during mastication |
| composition of the palate | forms the roof of the mouth in two parts - hard palate anteriorly and soft palate posteriorly |
| composition and function of the tongue | interlacing intrinsic and extrinsic skeletal muscle to reposition food when chewing, mix food with saliva, initiate swallowing and to form consonants for speech |
| intrinsic muscle of the tongue | originates and inserts on the tongue |
| extrinsic muscle of the tongue | originates elsewhere and inserts on the tongue - generally for in/out and side to side movements |
| salivary glands' function | produce saliva which: cleans the mouth; dissolves food chemicals for taste; moistens food; contains chemicals begin the breakdown of starches |
| name of the enzyme responsible for initiating the breakdown of starch | salivary amylase |
| composition and function of the pharynx | the oropharynx and laryngopharynx provide a common passageway for food, fluids and air |
| composition and function of the esophagus | runs from the laryngopharynx to the cardiac orifice of the stomach providing a passage for food and fluids |
| two stages of the digestive process in the mouth and esophagus | mastication and deglutition |
| mastication | chewing - begins the mechanical breakdown of food |
| deglutition | swallowing - occurs in two phases: buccal and pharyngeal-esophageal phase |
| buccal phase of swallowing | voluntary and occurs in the mouth as bolus is forced into the oropharynx |
| pharyngeal-esophageal phase of swallowing | involuntary and occurs as bolus is squeezed through the pharynx into the esophagus |
| function of the stomach | temporary storage tank for food where the chemical breakdown of proteins in initiated and food is converted to chyme |
| chyme | food broken down to a mushy liquid for processing |
| size of the adult stomach | 15-25 cm long with diameter and volume dependent on its contents |
| major regions of the stomach | cardiac, fundus, body, pyloric |
| cardiac region | the entrance to the stomach; connected to the esophagus by the cardiac orifice |
| fundus | area at the top of the stomach above the cardiac orifice |
| body | most of the stomach - from the fundus to the pyloric region |
| pyloric region | starts roughly at the bottom of the greater and lesser curvature; three regions |
| three areas of the pyloric region | pyloric antrum, pyloric canal, pylorus |
| pyloric antrum | the broad area of the pyloric region at the base of the curvatures |
| pyloric canal | where the pyloric region narrows as it leads to the pylorus |
| pylorus | the distal end of the stomach that connects to the duodenum; terminates at the pyloric valve or sphincter which controls gastric emptying |
| lateral outer convex surface of the stomach | greater curvature |
| medial outer convex surface of the stomach | lesser curvature |
| composition of the stomach mucosa | simple columnar epithelium |
| gastric glands function | produce gastric juices containing mucous, HCl, intrinsic factor, pepsinogen and hormones |
| structure of gastric glands | formed in the epithelial layer of the mucosa - gastric pits descend to the gastric gland below consisting of goblet cells (mucous neck cells), parietal cells, chief cells and entero-endocrine cells |
| goblet cells function | produce mucous to protect the stomach from gastric juices and the digestive process |
| parietal cells function | produce HCl (to breakdown proteins) and intrinsic factor (to absorb B-12) |
| chief cells function | produce pepsinogen - a proteolytic enzyme that is inactive until combined with HCl and becomes pepsin |
| entero-endocrine cells function | produces hormones |
| gross anatomy of the small intestine | extends from the pyloric sphincter to the ileocecal valve, connecting to the LI |
| three subdivisions of the Small Intestine | duodenum, jejunum, and the ileum |
| section of the small intestine where most of the absorption of the GI tract occurs | jejunum |
| the deep circular folds of the mucosa and submucosa of the SI | plicae circulares |
| function of the plicae circulares | to increase the surface area of the mucosa of the SI for more absorption |
| villi | small, fingerlike projections of the mucosa of the SI for increased absorptive ability |
| microvilli | small fingerlike projections of the absorptive cells on the villi of the mucosa |
| the brush border | the brush like appearance of the absorptive cells of the villi of the SI created by the conglomeration of the microvilli |
| brush border enzymes | enzymes in the brush border that complete the digestion of carbs and proteins on the SI |
| components of the villi | the villi of the epithelial layer of the SI mucosa contains absorptive cells and goblet cells; the lamina propria contains lacteal and dense capillary supply |
| components of the mucosa of the SI not in the villi | the lamina propria below the villi contains MALT and intestinal crypts or crypts of Lieberkühn which contain enteroendocrine cells and absorptive cells |
| lacteal | a thick lymph passage in the center of the villi |
| function of the crypts of Lieberkühn | secretes intestinal juice that acts as a carrier fluid for the absorption of nutrients from the chyme and hormones |
| gross anatomy of the liver | it is the largest gland in the body and has four lobes; the largest is the right lobe |
| what separates the right and left lobes of the liver | the falciform ligament (mesentery) |
| functional unit of the liver | lobules - made of plates of liver cells (hepatocytes) |
| digestive function of the liver | produces bile |
| bile | a yellow-green, alkaline solution that emulsifies fat (reduces its surface tension) |
| duct through which bile is sent to the duodenum | common hepatic duct which meets the cystic duct and forms the bile duct |
| where bile that is not needed is stored and concentrated | the gall bladder; concentrates the bile as water leaves the GB |
| duct that connects the gall bladder to the liver and duodenum | the cystic duct connects the GB to the liver via the common hepatic duct and the duodenum via the bile duct |
| how bile typically enters the small intestine | when the gall bladder contracts |
| substance that causes the gall bladder to contract | cholecystokinin |
| function of the pancreas in digestion | an accessory gland that is retroperitoneal and secretes pancreatic juice to the duodenum to assist with the digestion of proteins, carbs and fats |
| composition of pancreatic juice | mostly water containing enzymes that breakdown food and electrolytes |
| how the secretion of pancreatic juice is regulated | local hormones and the parasympathetic nervous systems |
| functions of the large intestine | reabsorption of water and the elimination of indigestible materials as feces |
| three unique features of the LI | teniae coli, haustra, epiglopic appendages |
| teniae coli | the singular longitudinal layer or the muscularis externa in the LI that is in a continuous state of tone, creating pockets in the LI called haustra |
| haustra | the pockets in the LI created by the teniae coli |
| epiglopic appendages | fat-filled pouches in the visceral peritoneum whose function is unknown |
| five subdivisions of the LI | cecum, appendix, colon, rectum and anal canal |
| cecum | the "blind pouch" which lies below the ileocecal valve connecting the LI to the SI and is the first part of the LI |
| vermiform appendix | contains MALT and is important in the immune system |
| colon | the retroperitoneal portion of the LI except the transverse and sigmoid portions |
| major subdivisions of the colon | ascending colon, hepatic flexure, transverse colon, splenic flexure, descending colon, sigmoid colon |
| part of the LI distal to the sigmoid colon | the rectum |
| the part of the LI distal to the rectum and the last segment of the LI | the anal canal which contains the internal and external anal sphincters |
| the distal, exterior opening of the GI tract | the anus |
| source of bacteria in the colon and their function | enter the colon via the SI and anus and aid in the fermentation of indigestible carbs |
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