The fibrous skeleton of the heart serves as electrical insulation between the atria and the ventricles
Parasympathetic stimulation reduces heart rate.
Repolarization of a ventricular cardiocyte takes longer than repolarization of a typical neuron.
The ventricles are almost empty at the end of ventricular diastole.
Endurance athletes commonly have a resting heart rate as low as 40 bpm, and stroke volume as low as 50 mL/beat.
_____ is the most superficial layer enclosing the heart?
The tricuspid valve regulates the opening between?
the right atrium and the right ventricle
Obstruction of the _____ will cause a more severe myocardia infarction (MI) than the obstruction of any of the others.
left coronary artery (LCA)
Which of these is NOT part of the cardiac conduction system?
the tendinous cords (TC)
The pacemaker potential is a result of
If the sinoatrial (SA) is damaged, the heart will likely beat at?
40 to 50 bpm
Atrial depolarization begins during?
the P wave
When the left ventricle contracts the ____ valve closes and the ____ valve is pushed open.
During isovolumetric contraction, the pressure in the ventricles?
Most of the ventricle filling occurs?
during atrial diastole.
Congestive heart failure (CHF) of the right ventricle?
can cause systemic edema
the volume of blood ejected by each ventricle in one min. is called?
the caridac output
The mechanisim that keeps the testes cooler than the bodys core temp. is called descent of the testes?
Sustentacular cells secrete inhibin, which regulates the rate of sperm production.
At early puberty, follic stimulating hormone (FSH) and lutenizing hormone (LH) stimulat enlargment of the testes.
Only germ cells undergo meiosis which produces four haploid cells withing 23 chromosomes each.
Myotonia of skeletal muscles is characteristic of the excitment phase and refractory period.
Which of the following is a secondary sex organ?
The gene that codes for the testis-determining factor (TDF) is found in or on?
the Y chromosome.
____ stimulates the descent of the testes?
From their formation to ejaculation, sperm cells take the follwiing pathway?
seminiferou tubule, rete testis, epididymis, ductus deferens, ejaculatory duct, urethra (SRED)
The blood-testis barrier?
prevents antibodies in the blood from getting to the germ cells
The penile urethra is enclosed by the?
The____ is/are the site(s) of sperm maturation and storage.
Which of the following hormones directly stiumlates the development of male secondary sex characteristics?
Which hormone suppresses spermatogenesis without affecting testosterone secretion?
Changes called male climacteric are a consequence of?
increased secretion of FSH and LH
In meiosis, each parent cell produces?
four haploid cells.
The most important role of meiosis in sexual reproduction is?
that it prevents the chromosome number from doubling in each generation
Male infertility (sterility) refers to?
the inability to fertilize an egg.
A sperm count any lower than ____ million sperm per mL of semen is usually associate with infertility.
20 to 25
an autonomic reflex meditated predoimantly by PARASYMPTHETIC nerve fiberes.
Blood flow is pulsatile in arteries and veins but it is steady in capillaries.
Most tissue fluid is reabsorbed by the lymphatic system.
Lung tissue receives nourishment and waste removal from the pulonary circut?
Blood filtered through the hepatic sinusoids exists the liver via the hepatic veins.
The radial artery is lateral to the ulnar artery.
The outermost wall of an arter or vein is called the ____ and in large arteries and veins contains the ____.
tunica externa; vasa vasorum
These are all possible circulatory routs from the hear except....
heart > arteries > capillary bed >vein > capillary bed > arteries > heart
The medullary ischemic reflex results in?
increased circulation to the brain
All of these increase blood pressure except?
atrial natriuretic peptide
_____ are powerful vasoconstrictors, and _____ also increases heart rate.
Epinephrine and angiotensin II, epinephrine
_____ by the capillaries at their venous end.
Ammonia is taken up.
_____ would NOT increase capillary filtration.
Obstructed venous return
_____ shock can be produced by hemorrhage, severe burns or dehydration.
Myocardial infarction can lead to ______ shock.
Pulmonary arteries have______ vlood pressure compared to systemic arteries.
There are no _____ in humans.
right and left brachiocephalic ARTERIES.
The cerebral arterial circle (circle of Willis) is?
an anastomosis surrounding the pituitary gland
The principal venous drainage of the thoracis organs is accomplished bythe way of?
the azygos system
Testosterone is a gonadotropin.
Thyroid hormone has a calorigenic effect.
Peptide hormones are synthesized by cytoplasmic ribosomes as active enzymes.
Eicosanoids are derived from steroids.
Addison disease is a consequence of a tumor of the adrenal medulla.
__ are secreted by one cell into the tissue fluid, diffuse to nearby cells in the same tissue, and stimulate their physiology.
The ___ is not an endocrine gland but it has a role in endocrine function.
Thyrotropin-releasing hormone targets the ?
anterior pituitary (adenohypophysis)
Antidiuretic hormone (ADH) targets the
The infundibulum is?
a projection of the hypothalamus in which the pituitary gland hangs
The ___ secretes several hormones that stimulate the development of lymphatic organs and regulates development and activity of T cells (white blood cells).
The ___ secrete(s) ___, which promotes Na+ and water retention.
adrenal cortex; aldosterone
These are all secreted by the pancreas except
somotropin (growth hormone)
___ is synthesized in the rough endoplasmic reticulum?
___ enters the target cell's nuclei and acts directly on the genes.
During the exhaustion stage of the general adaptation syndrome (stress response) stress overwhelms homeostasis. A characteristic of this stage is that?
energy demandands are primarily met by CARBOHYDRATE metabolisim
Eicosanoids are derived from?
Diabetes insipidus is caused by?
antidiuretic hormone (ADH) HYPOsecretion.
Diabetes mellitus is characterized by the following except?
Lymphoid hemopoiesis occurs mainly in the bone marrow.
The most important components of the cytoplasm of RBCs are hemoglobin and carbonic anhydrase.
Rh incompatibility between a sensitized Rh+ woman and an Rh- fetus can cause hemolytic disease of the newborn.
Monocytes differentiate into large phagocytic cells.
After a wound is sealed, tissue repair is followed by fibrinolysis.
Hematocrit is ____________ of the total blood volume.
_____________ is the most abundant protein in plasma.
Tissues can become edematous (swollen) when?
there is dietery protein sufficency
Erythrocytes transport oxygen and serve to?
transport carbon dioxide
An increased erythropoietin (EPO) output by the kidneys would lead to all of the following except?
______________ is more likely to cause anemia than any of the other factors below.
Correction of hypoxemia is regulated by?
a NEGATIVE feedback loop
The ABO blood group is determined by _____________ in the plasma membrane of RBCs.
RhoGAM is an antibody given to Rh- women who give birth to a Rh+ child. RhoGAM is what type of plasma protein?
gamma (y) globulin
The main reason why an individual AB, Rh-negative cannot donate blood to an individual A, Rh-positive is because?
anti-B antibodies in the RECIPIENT will agglutinate RBCs of the donor.
These are the most abundant agranulocytes.
Leukopoiesis begins with the differentiation of?
Pluripotent stem cells (PPSCs)
All these can cause leukopenia except?
The cessation of bleeding is specifically called?
All of these prevent the spontaneous formation of a clot except?
presence of tissue thromboplastin
Most strokes and heart attacks are caused by the abnormal clotting of blood in an unbroken vessel. Moreover, a piece of the ____________ (clot) may break loose and begin to travel in the bloodstream as a(n) ______________.
The vagina has no glands but it is moistened by mucus from glands in the cervical canal.
The number of ovarian follicles declines with age, leading to a reduction of estrogen levels.
The proliferative phase of the uterus is drive by estrogen from the ovaries?
Human chronic gonadotropin (HCG) stimulates the corpus luteum to grow and secrete estrogen and progesterone.
Oxytocin stimulates contraction of myoepithelial cell of the mammary acini.
The ___ arteries rhythmically consrict and dialate causing the uterine mucose to blanch and flush with blood.
Most of the natural lubrication during female sexual excitment is proveded by the?
greater vestivular (Bartholin) glands
_____ are found in both male and femal external genitalia, but the ____ is/are only found in the female.
Corpora cavernosea; vestibular bulbs
Follicles are located in the?
cortex of the ovary.
_____ acts primarily in the uterus.
During climcteric, sudden ______ may cause hot flashes.
vasodilation of cutaneous arteries
The ovulated egg is at?
After expelling the oocyte, the follicle becomes the ____ and secreates_____.
corpus luteum; ESETROGEN AND PROGESTERONE
during embryonic development.
Which of these blood hormone levels reaches its maximum during the luteal phase?
The ____ phase is the one associasted with menstrul cramps and typically occurs _____ of the cycle.
premenstrual; days 27 to 28
During the plateau phase, the flans and clitoris swell as the _____ arteries dilate and the corpus and corpora _____ engorge with blood.
The basis of pregnancy test kits is the presence of ___, which is secreated by the _____.
human chorionic gonadotropin (HCG); blastocyst and placenta
The most abundant estrogen of pregnancy is ___, but one that accounts for the most of the estrogenic effects in pregnancy is ____.
Milk ejection, stimulation of nerve endings in the ____ leads to the release of _____ from the pituitary.
nipple and areola; oxytocin
The fertilization membrane is the endometrial tissue that receives the conceptus.
The embryonic stage extends from 16 days through the end of week 8.
Trophoblastic nutrition refers to the nutrition of the conceptus before it implants.
Premature infants suffer especially from multiple dysfunctions resulting from inadequate liver function.
Life expectancy has steadily incread in teh last century, whereas life span has not.
In the slow block to polyspermy, sperm penetration releases an inflow of _____, which in turn stimulates the ______.
CA2+; cortical reaction
The optimal "window of opportunity" to conveive a child is?
a few days before ovulation to less than a day after
In the blastocyst, the trophoblast will become_____, wheras the embryoblast will become______.
part of the placenta; the embryo
During implantation, the trophoblast divides into a deep layer, the ____, composed of individual cells, and a superficial layer, the _____, composed of multinucleate mass of cytoplasm.
Prior to ejaculation, ____ in the sperm membrane prevents premature release of ____.
cholesterol; acrosomal enzymes
By the end of 8 weeks, the individual is considered a fetus because...
all of the organ systems are present.
In fetal circulation, the ____ bypassses the liver and the _____ bypasses the lungs.
ductus VENOSUS, ductus arteriosus
Oxygenated blood reaches the fetus through the?
The digital rays of a fetus give rise to?
fingers and toes
During birth, an infant is normally stimulated to breath by?
CO2 accumulating in the babys blood.
Which of these organ systems faces the greatest physiological challenge in the transitional period after birth?
Down syndrome (trisomy-21) results from
Urine retention is greater problem for elderly men than for elederly women because men
usually develop benign prostatic hyperplasia
are DNA segments at each end of a chromosome.
Which of the following systems shows the least overall senescene?
Mucous membranes prevent most pathogens from entering the body because of the stickiness of the mucus and the presence of lysozymes.
Pyrogens act by increasing the set point for body tempature in teh thalamus.
Helper T cells respond only to epitopes attached to MHC proteins.
Naive T cells can synthesize antibodies.
Some antibodies against foreign antigens can react to similar self-antigens causing an autoimmune disease.
Special lymphatic vessels called lacteals absorb dietary ___ that are not absorbed by the blood capillaries.
_____ are the largest of the lymphatic vessels and they empty into the ____.
Collecting ducts; subclavian veins
This is the only lymphatic organ with afferent lymphatic vessels.
____ are found especially in the myucous membrane, standing guard against parasites, and allergens.
____ are secreted by cells infect with viruses, alerting neighboring cells and protection them from becoming infected.
This is the first of a series of neutrophil behaviorsin inflammation?
All these cellular agents participate in inflammation except?
cytotoxic T cells
___ are antimicrobial proteins.
Cellular (cell-meditated) immunity is efefctive against?
T cells undergo positive selection in the thymus which means?
they multiply and form clones of identical T cells
All of the following can act as antigen-presenting cells except?
Helpter T (TH) cells do not?
secrete fever producing chemicals
Memory T cells can live up to?
Each immunoglobulin (Ig) has___ antigen-bonding site(s).
Before B cells secrete antibodies they differentiate into?
Beta cell destruction that causes type 1 diabetes mellitus is a(n)
type IV (delayed) hypersensitivity
The nose is divided into right and left halves termed the?
The most numerous cells in the lungs are called
What is the basic distinction between an aveolar duct and alveolar atrium?
____ states that the total pressure of a gas mixture is equal to the sum of the partial pressure of its individual gases.
Vital capacity consist of?
expiratory reserve volume + tidal volume+inspiratory reserve volume
Carbon dioxide is transported by all the following means except
Which of the following would slow down gas exchange between the blood and alveolar air?
an increase in membrane thickness
Which has the highest concentration in the air we brethe?
Which of the following enzymes in an RBC breaks H2CO3 down to water and carbon dioxide?
Congestive heart failure results in which of the following?
A lung disease marked by abnormally few but large alveoli is?
Polio can sometimes damage the brainstem respiratory centers in result in?
Nitrogen bubbles can form in the blood and other tissues when a scuba diver ascends too rapidly, producing?
The blood transports more CO2 in the form of___ than in any other form.
Your breath rate is 12 breaths/min; your tidal volume is 500 mL; your vital capacity is 4700 mL; and your daed air space is 150 mL. Your alveolar ventilation rate is ___ mL/min.
Respiratory arrest is an irreversible condition.
The rate of oxygen diffusion is affected by the pressure gradient of carbon dioxide.
According to the Bohr effect, a low level of oxyhemoglobin enables the blood to transport more CO2.
Which organ system does not excrete waste?
the cardivascular system
Which of the following is not an organ of the urinary system?
A single lobe of a kidney is compromised of?
one pyramid and the overlying cortex
The transition from an afferent arteriole to an efferent arteriole occurs in the?
Blood plasma is filtered in?
the renal corpuscle
Which are primarily responsible for maintaining teh salinity gradient of the renal medulla?
In healthy kidney, very little ___ is filtered by the glomerulus.
In response to a drop in the overall blood pressure, ___ stimulates constriction of the glomerular inlet and even greater constriction of the outlet.
Because of the great deal of active transport that occurs here, the ___ of all the nephrons collectively account for about 6% of ones daily resting ATP and caloric consumption.
proximal convulated tubules
Which of the followin is a direct result of antidiuretic hormones?
decreased urine volume
secreation of parathyroid hormone
Which of the following doesnot contribute to water conservation?
Which of these induces renin secretion, constricts afferent arterioles, and reduces GFR and urine volume?
The minimum daily outputof urine to meet the defintion of polyuria is?
A hospital patient produces 4 mL of urine with a urea concentration of 8 mg Venous blood draw reveals urea concentration of .4 mg. What is the percentage of cleared urea from glomerular filtrate?
Which of the following is not found in the ureter?
Which is not a protion of the urethra?
Internal urethral sphincter
Lithotripsy is a medical procedure used to treat?
Albuminuria is a common sign of diabetes mellitus.
Ethyl (drinking) alcohol stimulates the secreation of ADH, thereby reducing reabsorption by the collection duct.
The countercurrent multiplier mechanism for water conservation was discovered by limiting studies to humans thus hypothesizing how form detemines function.
Angiotensin-converting enzy is found only in the kidneys and converts angiotensiongen to agiotensin I.
The fenestrated endothelium of the capillary has pores small enough to exclude blood cells from the filtrate.
Odor, sight, and taste stimulate salivatory nuclei in the cerebral cortex.
Gastric juice consists entirely of water and hydrochloric acid.
Both pancreatic juice and bile are secreted int the duodenum.
Most fat is disgest by pancreatic lipase.
The large intestine is longer than the small intestine.
These are all accessory organs of the digestive system except?
Chemical digestion breaks down ___ into___.
nucleic acids; nucleotides
Infants have ___ deciduous teeth, whereas adults have ____ permanent teeth.
The ___ gland is an extrinsic savilary gland; whereas the ____ gland is an intrinsic savilary gland.
Acid refulx into the esophagus ("heartburn") isnormally prevent by?
the lower esophageal sphincter (LES)
___ , which is secreted by ____ cells, is necessary for Vitamin B12 absorption.
Inrinsic factor; parietal
The enterogastric reflex serves to?
inhibit gastric motility when there is chyme in the small intestine.
The organ that stores excess glucose and releases it later into the blood is?
The ___ synthesizes bile acids by metabolizing ___.
Which of these nutrients is absorbed by teh lacteals of the small intestine?
The small intestine has very large absoptive surface associate with all these structures except?
Carbohydrate digestion begins in the ___, whereas protein digestion begins in the ____.
Amino acids and monosaccharides are absorved in the ____, and fatty acids are absorved in the ____.
small intestine; small intestine too.
___ transport lipids to the surface of the intestinal absorptive cells, which process them into ___.
Bacterial flora carry out all of the following except?
digest most of the proteins we get in teh diet.
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