Physiology Exams 1,2,&3 MC only

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3) Which is TRUE about the condition anemia? A) It can be caused by too little iron in the diet. B) It can be caused by kidney failure. C) It can be caused by abnormal hemoglobin. D) It results in reduced oxygen-carrying capacity of the blood. E) All of the answers are true.

31) Which is TRUE regarding the regulation of heart rate? A) Stimulation of parasympathetic nerves to the heart causes a slowing of heart rate. B) Stimulation of sympathetic nerves to the heart causes an increase in heart rate. C) A person whose heart lacks autonomic innervation has a faster heart rate at rest than a person with a normally innervated heart. D) The slope of diastolic depolarization in SA node cell action potentials determines the heart rate. E) All of the choices are true.

36) Which of the following is NOT a determinant of whole-muscle tension? A) The number of muscle fibers contracting B) The tension produced by each contracting fiber C) The numbers of motor units recruited D) The frequency of motor neuron stimulation E) The proportion of the muscle fibers within each motor unit that are contracting at any given time

4) What is the best definition of the "receptive field" of an afferent neuron? A) The number of interneurons with which the central process of the afferent neuron makes synaptic contact via divergence B) The type of stimulus energy to which the afferent neuron is most sensitive C) All of the interneuron cell bodies and dendrites onto which the afferent neuron synapses D) The area of the cerebral cortex in which information from that afferent neuron is initially received E) The area of the body that, when stimulated, leads to activity in that particular afferent neuron

41) If the arterial blood pressure in the brain is suddenly decreased, the flow through arterioles in the brain will immediately fall and then which of these will occur next? A) Brain arterioles will constrict to accelerate blood flow through the brain capillaries. B) Brain arterioles will dilate due to a decrease in levels of CO2. C) Blood flow will remain at the new, lower level due to reactive hyperemia. D) Blood flow will rise to levels above normal due to excess O2 levels. E) Blood flow will return toward its original level due to flow autoregulation.

43) Which of the following statements regarding the vestibular system is TRUE? A) Hair cells in the cochlea are involved in the detection of movement and position of the head. B) The utricle and saccule are mainly responsible for detecting angular rotation of the head. C) The vestibular apparatus is principally involved in our ability to detect and interpret sound. D) Deflection of the basilar membrane by fluid moving within the semicircular canals allows us to detect rotational movement of the head. E) Receptors in the utricle and saccule detect changes in the position of the head with respect to gravity.

49) What determines the movement of blood in systemic veins? A) The blood pressure difference between systemic capillaries and the right atrium B) The contraction and relaxation of skeletal muscles C) The decrease of thoracic pressure and increase of abdominal pressure due to diaphragm movement D) Valves in the veins E) All of the these

51) Which of the following does NOT correctly describe cardiac muscle cells? A) They are arranged in layers surrounding hollow cavities in the heart. B) They are much shorter than skeletal muscle fibers, and generally have a single nucleus. C) Their membranes are depolarized initially by the influx of sodium ions. D) They depolarize prior to contraction. E) They can contract in the absence of external calcium.

When you head to bed at night, you bring a glass of tap water with you and set it on the nightstand. Upon waking in the morning, you discover there are tiny gas bubbles along the sides of the container. The best explanation for this is A) the concentration of a particular gas in a liquid equilibrates to match the concentration of that gas in the air to which the liquid is exposed. B) different gasses have the same solubility in liquids. C) the partial pressure of a gas in a liquid is equal to the amount freely diffusing in the liquid plus the amount bound to large molecules within the liquid. D) the partial pressure of a particular gas in a liquid equilibrates to match the partial pressure of that gas in the air to which the liquid is exposed. E) as the partial pressure of a particular gas in an air sample increases, the concentration of that gas in a liquid exposed to that air sample decreases.

Which is NOT a transport mechanism typically seen in renal tubular epithelial cells? A) Cotransport proteins in the luminal membrane of the proximal tubule that move Na+ and glucose from the proximal tubule into epithelial cells B) Transport proteins that move glucose by facilitated diffusion from inside of proximal tubule cells into the renal interstitial fluid C) Ion channels that allow Na+ to move by diffusion from the lumen of the proximal tubule into epithelial cells D) Na+-K+ ATPase pumps in the luminal membrane of proximal tubule epithelial cells that move Na+ from inside the cell into the tubule and K+ from the tubule lumen into the cell E) Countertransport proteins that move Na+ into proximal tubule epithelial cells while moving H+ from the cells into the lumen

Which is a function of the gonadotropic hormones? A) Stimulating the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) B) Inhibiting the release of growth hormone C) Inhibiting the release of prolactin D) Inducing the secretion of steroid hormones by the gonads in both males and females E) Stimulating the release of gonadotropin-releasing hormone (GnRH)

Which of the following hormones is NOT secreted by the anterior pituitary gland? A) Somatotropin B) Prolactin C) Corticotropin D) Erythropoietin E) Thyroid-stimulating hormone (TSH)

Which of the following is most responsible for keeping the lung surface and the thoracic wall from separating? A) The presence of surfactant B) The negative pressure in the alveolar space C) The force exerted by the external intercostal muscles D) Subatmospheric intrapleural pressure E) Alveolar pressure is higher than atmospheric pressure

Which of the following statements about hormone synthesis is NOT correct? A) Progesterone can be a precursor of cortisol. B) Progesterone is a precursor of mineralocorticoid and glucocorticoid hormones. C) Pregnenolone is a precursor for all steroid hormones. D) Tryptophan is a precursor for thyroid hormones. E) Peptide hormones are polymers of amino acids.

Which of the following statements regarding renal handling of Na+ is correct? A) In the proximal tubule, Na+ is actively transported across the luminal membrane of the tubular epithelial cells. B) Atrial natriuretic factor increases Na+ reabsorption. C) In the absence of aldosterone, Na+ will be secreted by the cortical collecting ducts. D) Na+ is actively reabsorbed in the ascending limb of the loop of Henle. E) Without vasopressin, the collecting duct is impermeable to Na+.

Which of these would tend to increase ventilation? A) Lower than normal arterial PCO2 B) Higher than normal arterial pH C) Breathing carbon monoxide D) Breathing air with increased PCO2 E) Iron-deficiency anemia

Which structure is NOT part of the "anatomical dead space"? A) Bronchiole B) Trachea C) Bronchus D) Respiratory bronchiole E) Terminal bronchiole

Which would result in the greatest stimulation of aldosterone secretion? A) Increasing plasma K+ concentration and decreasing plasma angiotensin II concentration B) Decreasing plasma K+ concentration and increasing plasma angiotensin II concentration C) Increasing plasma Na+ concentration and increasing plasma volume D) Increasing plasma K+ concentration and increasing plasma angiotensin II concentration E) Decreasing plasma Na+ concentration and decreasing plasma angiotensin II concentration

You are the CEO of a drug company where you've asked five teams of scientists to generate new drugs to decrease blood pressure. You can only send four of the drugs to market. Which of these drugs is least likely to decrease blood pressure and can be eliminated from potential development? A) A drug that interferes with aldosterone synthesis B) A drug that is an agonist of atrial natriuretic factor C) A drug that decreases sympathetic stimulation of renal arterioles D) A drug that enhances the activity of angiotensin-converting enzyme E) A drug that decreases liver production of angiotensinogen

You have discovered a novel hormone. Early experiments have shown that it is quite hydrophobic. Which of the following is likely to also be TRUE of these hormones? A) They mostly bind to receptor proteins in the surface membrane of target cells. B) They are generally polar molecules. C) They usually have very rapid effects on target cells. D) Their mechanism of action generally involves altering protein synthesis. E) They are highly soluble in blood plasma.

You play a trick on your little brother and replace all the sugar in the sugar bowl with salt. In the morning, you find him eating a bowl full of cereal with salt on it. You realize he's eaten quite a bit of salt! Which is likely to occur? A) Urine osmolarity would decrease. B) Atrial natriuretic factor secretion would decrease. C) Firing by hypothalamic osmoreceptors would decrease. D) Secretion of atrial natriuretic factor would increase. E) Secretion of vasopressin would decrease.

Your patient has advanced stage cancer and her liver is starting to fail. One consequence is markedly reduced plasma proteins. In what way might this affect her endocrine system? A) Transport of all hormones in the blood is compromised B) No change to endocrine system function C) A reduction in the synthesis of steroid hormones by the liver D) A reduction in the rate of hydrophobic hormones like steroid and thyroid hormones reaching their target tissues E) A reduction in the rate of peptide-type hormones reaching their target tissues

1) Which of the following is NOT primarily a function of blood plasma? A) Transport of hormones B) Being in osmotic balance with red blood cells C) Having plasma proteins that exert an osmotic pressure favoring fluid absorption into the capillaries D) Providing clotting factors that are ready to be activated E) Transport of oxygen

13) Which of the following statements regarding the precision of locating a somatic stimulus is FALSE? A) The precision is greater in areas of the body that have small, overlapping receptive fields than in areas with large, nonoverlapping receptive fields. B) The precision is greater in the lips and fingers than on the back. C) The precision is greater for the skin than for the internal organs. D) Lateral inhibition of parallel afferent pathways increases the precision of locating a stimulus. E) Convergence of afferent neurons onto common ascending pathways increases acuity.

15) Regarding schizophrenia, A) it is a family of mental disorders that involves disturbances of thinking, perceiving, and control of motor activity. B) its symptoms can include paranoid delusions and hallucinations. C) it probably has a hereditary component. D) both "it is a family of mental disorders that involves disturbances of thinking, perceiving, and control of motor activity" and "its symptoms can include paranoid delusions and hallucinations" are correct. E) All of the choices are correct.

18) If a muscle cell expressed muscarinic ACh channels, which are only permeable to Na+ instead of nicotinic ACh channels, which are permeable to both Na+ and K+, which portion of a muscle cell would be inhibited? A) Neurotransmitter release from the motor neuron B) Muscle cell depolarization C) Cross-bridge cycling D) Relaxation E) None of the answer choices are correct

18) Would SSRIs be useful therapies for schizophrenia? A) Yes, because they increase the availability of dopamine. B) Yes, because they increase the availability of acetylcholine. C) No, because they increase the availability of norepinephrine. D) No, because they increase the availability of enkephalin. E) No, because they increase the availability of serotonin.

24) A person struggling with a stressful exam question might experience difficulty focusing her eyes on the paper because A) she suddenly develops presbyopia. B) activation of her parasympathetic nerves causes sudden contraction of her ciliary muscles. C) activation of her sympathetic nerves causes sudden contraction of her ciliary muscles. D) activation of her parasympathetic nerves inhibits contraction of her ciliary muscles. E) activation of her sympathetic nerves inhibits contraction of her ciliary muscles.

25) Attention deficit hyperactivity disorder (ADHD) is a neurobehavioral problem that is primarily anatomically linked to which area of dysfunction in the brain? A) Basal nuclei B) Pituitary gland C) Prefrontal cerebral cortex D) Both basal nuclei and pituitary gland E) Both basal nuclei and prefrontal cerebral cortex

27) How is the length of a skeletal muscle cell related to the force it can generate? A) The tension in a skeletal muscle cell is greatest when contractions occur at either very short or very long lengths. B) Skeletal muscle cells generate the same amount of force, regardless of their length. C) The shorter a skeletal muscle cell is when it begins to contract, the stronger the force generation will be. D) The longer a skeletal muscle cell is when it begins to contract, the stronger the force generation will be. E) Skeletal muscle cells generate the most force when the contraction occurs at an intermediate length.

29) Which best defines cardiac output? A) The end-diastolic volume minus the end-systolic volume B) The output of the aortic arch baroreceptors C) The volume of blood in the arterial tree at any moment in time D) The stroke volume divided by the heart rate E) The product of the heart rate and the volume ejected from the ventricle during a cardiac cycle

52) Which of the following choices lists a correct sequence of events following the depolarization of transverse tubules in excitation-contraction coupling in cardiac muscle? A) Calcium release into cytosol, calcium ion influx through sarcolemma, actin and myosin attach, thin filaments slide toward the middle of sarcomeres B) Actin and myosin attach, thin filaments slide toward the middle of sarcomeres, calcium release into cytosol C) Calcium release into cytosol, actin and myosin attach, calcium ion influx through sarcolemma, thin myofilaments slide toward the middle of sarcomeres D) Calcium release into cytosol, actin and myosin attach, thin filaments slide toward the middle of sarcomeres, calcium ion influx through sarcolemma E) Calcium ion influx through sarcolemma, calcium release into cytosol, actin and myosin attach, thin myofilaments slide toward the middle of sarcomeres

53) Which of the following is a result of increased sympathetic stimulation of vascular smooth muscle? A) Filtration of fluid from capillaries to interstitial fluid increases. B) Total peripheral resistance (TPR) decreases. C) The percentage of blood volume in the veins increases. D) Blood flow to the brain decreases. E) Venous return of blood to the heart increases.

56) Which dietary supplement is most likely to contribute to greater skeletal muscle ATP availability in the first few seconds of skeletal muscle contraction? A) Fatty acids B) Sports drinks with electrolytes C) Sugar D) Protein E) Creatine

69) Arterial systolic pressure occurs ________ while arterial diastolic pressure occurs ________. A) at the same time as closure of the semilunar valves; at the same time as closure of the atrioventricular valves B) during the isovolumetric contraction phase of the cardiac cycle; during the isovolumetric relaxation phase of the cardiac cycle C) at the same time as the P-wave of the electrocardiogram; at the same time as the T-wave of the electrocardiogram D) when the ventricle reaches end-systolic volume; when the ventricle reaches end-diastolic volume E) during the middle of the phase of ventricular ejection; just before the semilunar valve opens

8) You are the technician running the fMRI (functional magentic resonance imaging) machine today. You have had a patient in the machine for quite a while when you notice a sudden change in electrical activity within the RAS. What might be happening? A) She is thinking about food. B) She fell asleep. C) She is moving. D) She is talking. E) She has opened her eyes and is taking in visual information.

80) Which of the following statements regarding the dissolving of blood clots is FALSE? A) Activation of the reactions that lead to blood clotting ultimately lead to blood clot dissolution. B) Tissue plasminogen activator (t-PA) is secreted by endothelial cells. C) Blood clots are digested by plasmin. D) Plasminogen is an inactive precursor of the enzyme plasmin. E) It involves aggregation of soluble fibrin fragments into fibrin.

82) Which correctly describes functions of protein C? A) It activates platelets and converts prothrombin to thrombin. B) It activates clotting factor XII and platelets. C) It binds to tissue factor and activates clotting factor VII. D) It inactivates thrombin and converts fibrinogen to fibrin. E) It inhibits clot formation and inactivates factors Va and VIIIa.

A deficiency in dietary iodine can cause A) congenital hypothyroidism (cretinism). B) a slowing of mental functions. C) a low metabolic rate. D) a goiter. E) All of the choices are correct.

A hormone may be A) inactivated by its target cell. B) activated by its target cell. C) inactivated by nontarget cells. D) excreted before it has a chance to act on a target cell. E) All of the choices could be correct.

A patient appears in a clinic complaining of irritability and chronic sweatiness. He also has a lump in his neck near his larynx. Blood tests show he has low levels of thyroid-stimulating hormone (TSH) in his plasma. Which of the following is the most likely diagnosis? A) Primary hypothyroidism B) An iodine-insufficient diet C) Secondary hypothyroidism D) Hyposecretion of TRH E) Graves' disease

After a day of fasting during Ramadan, Amira's blood Na+ level is quite low. Which of the following is likely to occur? A) An increase in plasma volume, which induces an increase in GFR and Na+ reabsorption rate B) A decrease in plasma volume, which induces an increase in GFR and Na+ reabsorption rate C) An increase in plasma volume, which induces an increase in GFR and a decrease in Na+ reabsorption rate D) A decrease in plasma volume, which induces a decrease in GFR and Na+ reabsorption rate E) A decrease in plasma volume, which induces a decrease in GFR and an increase in Na+ reabsorption rate

All of the following substances are present in proximal tubular fluid in the kidney, but which one is NOT normally present in urine? A) Ca2+ B) H+ C) K+ D) HPO42- E) Glucose

Carl has hypothyroidism and therefore his Na+/K+ ATPase pumps are functioning at a reduced rate. Will there be any effect on the transport of Na+? A) There will be a reduction in Na+ transport in Bowman's capsule epithelial cells. B) There will be a reduction in ATP-dependent, Na+ transport on the apical side of the tubule epithelial cells. C) There will be a reduction in Na+ secretion on both sides of the tubule epithelial cells. D) There will be no change to Na+ transport. E) There will be a reduction in Na+ transport on the basolateral side of the tubule epithelial cells.

Following strenuous exercise, blood levels of lactic acid are ________ compared to pre-exercise levels. This change in acid concentration causes a reflex ________ in ventilation by activating ________. A) decreased; decrease; peripheral chemoreceptors B) decreased; decrease; central chemoreceptors C) increased; increase; baroreceptors in the aortic arch D) increased; increase; central chemoreceptors E) increased; increase; peripheral chemoreceptors

In which region of the nephron does the fractional reabsorption of water vary the most in response to variation in the state of hydration? A) The glomerulus B) The proximal convoluted tubule C) The loop of Henle D) The distal convoluted tubule E) The collecting duct

What is the major hormone responsible for mediating the body's general response to stress? A) Thyroid hormone B) Growth hormone C) Testosterone D) Aldosterone E) Cortisol

Which are hormones secreted by the posterior pituitary? A) Vasopressin and dopamine B) Corticotropin and dopamine C) Oxytocin and prolactin D) Vasopressin and corticotropin E) Antidiuretic hormone (ADH) and oxytocin

Which correctly describes a basic renal process? A) Fluid is filtered from Bowman's capsule into the glomerulus. B) Substances are secreted from the tubule into the peritubular capillaries. C) Substances are reabsorbed from the peritubular capillaries into the tubular lumen. D) Substances are actively secreted from glomerular capillaries into Bowman's capsule. E) Fluid moves by bulk flow from glomerular capillaries into Bowman's space.

Which correctly describes the composition of the glomerular filtrate? A) It is identical to urine, but has a much smaller flow rate. B) It is identical to urine, but has a much larger flow rate. C) It is identical to blood plasma, except it lacks red blood cells. D) It is similar to plasma, except it does not contain glucose. E) It is similar to plasma, except it does not contain plasma proteins.

Which equation is equal to the net glomerular filtration pressure? A) GFP = hydrostatic pressure in glomerular capillaries - hydrostatic pressure in Bowman's capsule - osmotic pressure due to protein in Bowman's capsule B) GFP = osmotic pressure due to protein in plasma - hydrostatic pressure in glomerular capillaries - hydrostatic pressure in Bowman's capsule C) GFP = hydrostatic pressure in glomerular capillaries + hydrostatic pressure in Bowman's capsule + osmotic pressure due to protein in plasma D) GFP = hydrostatic pressure in glomerular capillaries + hydrostatic pressure in Bowman's capsule - osmotic pressure due to protein in plasma E) GFP = hydrostatic pressure in glomerular capillaries - hydrostatic pressure in Bowman's capsule - osmotic force due to proteins in plasma

Which is NOT an endocrine function performed by the liver? A) Secreting insulin-like growth factor 1 B) Clearing hormones from plasma C) Secreting angiotensinogen D) Producing plasma proteins that bind hormones E) Secreting insulin

Which is NOT true about receptors for steroid hormones? A) They may be proteins found in the nucleus. B) They undergo allosteric modulation when they bind to the hormone. C) They regulate gene transcription. D) They may be found in the nucleus. E) They are synthesized from cholesterol.

Which is NOT true about the countercurrent multiplier system of the kidney? A) It creates a hyperosmolar medullary interstitial fluid that allows the kidneys to form hypertonic urine. B) The descending loop of Henle is permeable to water. C) There is active transport of sodium and chloride out of the ascending limb of the loop of Henle. D) The ascending loop of Henle is not permeable to water. E) The fraction of filtered NaCl reabsorbed from the ascending limb equals the fraction of filtered water reabsorbed from the descending limb.

Which is true about the growth of long bones? A) Osteoblasts dissolve bone tissue when bones remodel in response to sex hormones. B) Osteoclasts are responsible for depositing new bone tissue at the epiphyseal growth plate before puberty. C) Before adolescence, bones are completely made up of cartilage; after puberty they ossify and harden. D) Growth in length occurs at a single epiphyseal growth plate in the center of the shaft of long bones. E) Growth in length occurs at two epiphyseal growth plates near the ends of long bones.

Which of the following is NOT true of pituitary growth hormone? A) It directly promotes protein anabolism in many cells. B) It causes differentiation of precursor cells that then respond to IGF-I by proliferating. C) Hypersecretion of growth hormone in adults leads to acromegaly. D) It is absent or deficient in pituitary dwarfs. E) It is necessary for fetal growth.

Which of the following most accurately describes the actions of aldosterone? A) Aldosterone increases Na+ secretion and K+ reabsorption in the cortical collecting ducts. B) Aldosterone increases Na+ reabsorption and K+ secretion in the proximal tubule. C) Aldosterone decreases Na+ reabsorption and K+ secretion in the cortical collecting ducts. D) Aldosterone increases Na+ secretion and K+ reabsorption in the proximal tubule. E) Aldosterone increases Na+ reabsorption and K+ secretion in the cortical collecting ducts.

Which of the following statements is NOT true of the endocrine system? A) It is one of two major regulatory systems of the body. B) It is composed of glands that secrete chemical messengers into the blood. C) It is an important regulator of homeostatic mechanisms. D) It influences and is influenced by the nervous system. E) Most of its components are anatomically connected, like most other systems of the body.

Which of the following would cause a decrease in the excretion of Na+ and water? A) Increased hydrostatic pressure in the afferent renal arterioles B) Increased mean arterial blood pressure C) Increased atrial distension D) Decreased aldosterone secretion E) Decreased atrial natriuretic peptide secretion

Which of these could be a cause of hypertrophy of the adrenal cortex? A) Autoimmune destruction of receptors for adrenocorticotropic hormone (ACTH) B) Autoimmune destruction of hypothalamic cells that secrete corticotropin-releasing hormone C) Injection of an excess of cortisol D) Destruction of the anterior pituitary by a stroke E) Low levels of cortisol in the circulation

Which one of the following substances is LEAST dependent on the kidney for regulation of its plasma concentration? A) Water B) Na+ C) K+ D) HPO42- E) Glucose

Which would NOT be caused by a decrease in plasma Ca2+ levels in an otherwise normal person? A) An increase in plasma parathyroid hormone levels B) An increase in plasma 1,25-dihydroxyvitamin D3 levels C) An increase in nerve and muscle excitability D) A decrease in the filtered load of Ca2+ E) An increase in bone density

Which would most directly decrease the production of aldosterone? A) Going on a low-salt diet B) Ingesting extra dietary vitamin D C) Reducing dietary tyrosine D) Increasing dietary cholesterol E) Injecting a drug that blocks the production of angiotensin II

You are designing an experiment to quantify the levels of stress experienced by different individuals. Which of the following tests would reveal insight as to a patient's chronic stress? A) Testing plasma levels of growth hormone B) Testing plasma levels of parathyroid hormone C) Testing plasma levels of dopamine D) Testing plasma levels of follicle-stimulating hormone E) Testing plasma levels of cortisol

53. Which of the following statements regarding neurotransmitters is TRUE? A. Acetylcholine is broken down by enzymes present on postsynaptic cell membranes. B. Acetylcholine that is released at synapses binds to adrenergic receptors in the postsynaptic cell membrane. C. Catecholamines are the most abundant neurotransmitters in the central nervous system. D. Opiate drugs, such as morphine, are antagonists of a class of neurotransmitters called endorphins. E. Gamma-aminobutyric acid (GABA) is a major excitatory transmitter in the central nervous system.

54. ATP is A. a nucleotide. B. a lipid. C. an amino acid. D. a carbohydrate. E. a steroid.

56. Which of the following enzymes is important for the metabolism of catecholamines? A. Tyrosine hydroxylase B. Acetylcholinesterase C. Superoxide dismutase D. Hydrocortinase E. Adenyl cyclase

56. Which of the following metabolic pathways can proceed in the absence of oxygen? A. glycolysis B. oxidative phosphorylation C. Krebs cycle D. the breakdown of fatty acids to CO2 and H2O E. None of the choices are correct.

58. Serotonin: A. acts as a neuromodulator. B. is a catecholamine neurotransmitter. C. is a neuropeptide. D. has an inhibitory effect on pathways that are involved in the control of muscles. E. has an excitatory effect on pathways that mediate sensations.

58. Which of the following is NOT a product of glycolysis? A. carbon dioxide B. ATP C. pyruvate D. NADH

6. The difference in electrical charge between two points: A. is called the potential difference between those points. B. is called the diffusion potential between those points. C. is called the the current, and is expressed in the units of millimoles. D. is the same for all ions.

61. Which is one of the most abundant excitatory neurotransmittors in the CNS? A. Glutamate B. Dopamine C. Norepinephrine D. Gamma-aminobutyric acid (GABA) E. Endorphin

65. Electrons transferred along the electron transport chain can be used to form: A. water. B. glucose. C. ATP. D. NADH. E. acetyl coenzyme A.

66. Which of the following does NOT result from the binding of nicotine with nicotinic acetylcholine receptors? A. a mild form of skeletal muscle paralysis that creates a more relaxed state B. signal transmission at neuromuscular junctions C. generation of excitatory signals within autonomic ganglia D. the release of norepinephrine, dopamine, and epinephrine E. facilitation of the release of multiple neurotransmitters within the brain, including the "reward pathway" involving dopamine

7. Methadone is a drug given to treat heroin addicts. It works by binding to the same receptors as heroin but with greater affinity, thereby preventing heroin from binding. This is an example of A. competition. B. down regulation. C. signal transduction. D. agonistic behavior. E. up regulation.

70. The cerebellum: A. is important for coordinating body movement. B. is the gray matter covering the entire surface of the brain. C. is the same thing as the brain stem. D. is in the anterior portion of the brain, just above the eyes. E. is one of the basal nuclei that is found deep inside the cerebrum.

72. Which is a FALSE statement about the cerebrospinal fluid? A. It has the same composition as blood plasma. B. It acts as a cushion for the brain and spinal cord. C. It is secreted by cells lining the ventricles of the brain. D. It circulates within and between brain ventricles and surrounds the spinal cord. E. It is in diffusion equilibrium with the extracellular fluid of the central nervous system.

73. Which of the following is NOT characteristic of the sympathetic division of the ANS? A. Preganglionic neurons tend to be long, with the ganglion located in or near the effector target tissue(s). B. Preganglionic neurons are short and synapse in ganglia located near the spinal cord. C. Preganglionic neurons release acetylcholine at synapses with postganglionic neurons. D. Postganglionic neurons release norepinephrine at their neuroeffector junctions. E. Postganglionic neuron cell bodies are located in the collateral chain ganglia (sympathetic trunk).

8. What cellular structures are most closely associated with vaults? A. nuclear pores B. peroxisomes C. lysosomes D. mitochondria E. gap junctions

9. Which is TRUE about the resting membrane potential? A. It requires very few ions to be distributed unevenly. B. It has the same value in all cells. C. It is oriented so that the cell's interior is positive with respect to the extracellular fluid. D. Only nerve and muscle cells have a potential difference across the membrane at rest. E. It is not altered by changing concentration gradients of permeating ions.

1. Which of the following statements regarding the structure and function of cell membranes is correct? A. The phospholipid bilayer is arranged so that the hydrophilic heads of the phospholipid molecule face the extra- and intracellular fluids. B. Some proteins integrated into the membrane serve as channels for the passage of nonpolar molecules through the membrane. C. Peripheral membrane proteins function as channels associated with transport of ions through the membrane. D. Cholesterol molecules function to transport ions from one side of the plasma membrane to the other. E. The plasma membrane is a layer of phospholipid molecules with their hyrophilic head groups in contact with the extracellular solution and the hydrophobic tail groups in contact with the intracellular solution.

11. Cells can increase their responsiveness to an external chemical regulator by A. increasing the number of their transmembrane receptors by exocytosis. B. decreasing the number of their transmembrane receptors by endocytosis. C. uncoupling their receptors from the second message generator. D. increasing the number of their transmembrane receptors by endocytosis. E. mutating their extracellular receptors so that the affinity for the chemical regulator is reduced.

11. Which is true about mediated transport of substances across cell membranes? A. It involves a specific membrane protein that functions as a carrier molecule. B. It always involves the movement of substances against a concentration gradient. C. It is always directly coupled to the splitting of ATP molecules. D. There is no limit to how fast it can occur as the concentration gradient becomes larger. E. It is the main mechanism for transporting hydrophobic molecules across membranes.

12. The diffusion potential due to the concentration gradient for Na+ across a nerve cell membrane: A. favors its movement into the cell at the resting membrane potential. B. favors its movement out of the cell at the resting membrane potential. C. is equal and opposite to the electrical potential acting on Na+ at the resting membrane potential. D. Is in the same direction as the diffusion potential due to the concentration gradient for K+. E. favors movement of Na+ in the opposite direction as the electrical potential acting on Na+ at the resting membrane potential.

13. What term is used to describe the steady state value for any variable that the body attempts to maintain? A. Set point B. Equilibrium potential C. Error signal D. Reflex arc E. Median value

13. Which is true regarding the mediated transport of a substance across a plasma membrane? A. It depends upon the binding of that substance to a specific site on the membrane protein. B. It depends upon movement of proteins from one side of the membrane to the other. C. It always increases in direct proportion to the increasing concentration of the substance on one side of the membrane. D. Both "depends upon the binding of that substance to a specific site on the membrane protein" and "depends upon movement of proteins from one side of the membrane to the other" are correct. E. All of the choices are correct.

13. Which of the following is not true of the cytoskeleton? A. It refers to the cellular components of bone. B. It refers to a network of cytoplasmic filaments. C. It is important for cellular movement. D. It helps to determine a cell's shape. E. It includes actin filaments.

13. Which would result from an increase in the extracellular concentration of K+ above normal? A. depolarization of resting nerve cells B. hyperpolarization of resting nerve cells C. The potassium equilibrium potential of nerve cells would become more negative. D. The sodium equilibrium potential would become less positive.

14. Cell A is a gland cell that makes and secretes proteins. Cell B is another type of cell that synthesizes and secretes steroids. If you were to look at electron micrographs of the two cells, what differences would you expect to see? A. Cell A would have more granular endoplasmic reticulum than cell B. B. Cell A would have fewer secretion granules than cell B. C. Cell A would have more agranular endoplasmic reticulum than cell B. D. Cell B would have more granular endoplasmic than cell A. E. The two cells would most likely look identical.

14. Which is TRUE about the Na+, K+ ATPase pump in neurons? A. It generates a small electrical potential such that the inside is made negative with respect to the outside. B. It maintains a concentration gradient for K+ such that diffusion forces favor movement of K+ into the cell. C. It maintains an electrical gradient at the equilibrium potential of K+. D. It transports equal numbers of sodium and potassium ions with each pump cycle. E. It pumps 3 Na+ ions into the cell for every 2 K+ ions it pumps out.

14. Which of the following is NOT typically true about G proteins? A. They act as second messengers. B. They can be stimulatory for second-messenger production. C. They can be inhibitory for second-messenger production. D. They can act as transducers for activated receptors by opening or closing ion channels.

15. Feedforward regulatory processes A. work in anticipation of changes in regulated variables. B. are identical to positive feedback processes C. Lead to instability of the regulated variable D. Maximize fluctuations in the regulated variable E. tend to force physiological variables away from their set point.

16. In Tay Sach's disease, lysosomes do not function normally. Predict which condition would be a symptom of Tay Sach's disease. A. There is excessive accumulation of damaged organelles in a cell. B. Cells are unable to synthesize proteins. C. Cells can only make ATP by glycolysis. D. Proteins cannot be secreted by exocytosis. E. Steroid hormones can't be produced.

17. In which organelle are carbohydrate chains added to glycoproteins? A. golgi apparatus B. smooth endoplasmic reticulum C. nucleus D. lysosome E. mitochondrion

17. The equilibrium potential of K+ ions in nerve cells is about -90 mV. The membrane potential of typical nerve cells at rest is -70 mV. Therefore A. Increasing the permeability of a resting neuronal membrane to K+ will make the membrane potential more negative inside with respect to outside. B. In resting neurons, there is a net diffusion of K+ into the cell. C. changing the resting membrane potential of a neuron to -80 mV would increase K+ diffusion rate out of the cell. D. potassium is the only permanent ion at rest. E. there must be another permanent ion with an equilibrium potential more negative than -90 mV.

17. Which of the following statements is true? A. Phosphorylation by protein kinases can stimulate or inhibit the activity of effector proteins. B. Ca2+ is not a second messenger. C. Phosphodiesterase converts GMP into cGMP D. Conversion of ATP to cAMP is a phosphorylation reaction. E. Phospholipase C converts ATP to cAMP.

18. Which of the following are known to be second messengers? A. diacylglycerol B. phospholipase C C. ATP D. adenylyl cyclase E. epinephrine

19. If the ATP-generating mechanisms in a cell are poisoned and the cell depletes its ATP reserves, which would occur first? A. Primary active transport of molecules would cease. B. Secondary active transport of molecules would cease. C. Facilitated diffusion of molecules would cease. D. Ion concentration gradients would reach equilibrium across the cell membrane. E. All transport processes would cease immediately when the ATP was depleted.

2. Which is TRUE regarding diffusion? A. It depends upon the random motion of molecules. B. It results in net movement of molecules from regions of low concentration to regions of high concentration. C. It is the principle mechanism by which molecules are moved over large distances in the body. D. It requires energy in the form of ATP. E. It requires integral membrane proteins to occur.

22. If all other conditions remain the same and the concentration of a nonpenetrating solute increases inside a cell, which is most likely to occur? A. Water will tend to enter the cell because the interior has an increased osmolarity. B. Water will tend to leave the cell because the interior has an increased osmolarity. C. Water will tend to enter the cell because the interior has a decreased osmolarity. D. Water will tend to leave the cell because the interior has a decreased osmolarity. E. The solute will diffuse across the membrane until its concentration is equal on both sides of the membrane.

23. What will happen if a normal cell is placed in a hypotonic solution? A. It will swell in size. B. It will shrink in size. C. It will stay the same size. D. The result can't be predicted.

25. How does the synthesis of proteins that are destined to be secreted differ from that of proteins with functions inside the cell? A. Proteins destined to be secreted have a signal sequence. B. Proteins destined to be secreted are synthesized on free ribosomes. C. Proteins destined to be secreted are packaged into secretory vesicles in the granular endoplasmic reticulum. D. Only proteins destined for secretion need transfer RNA to be synthesized. E. Genes for proteins with functions inside the cell are located in the cytoplasm.

25. If a normal cell is placed into an unknown solution and it shrinks, what can be concluded about the unknown solution? A. Its nonpenetrating solute concentration is greater than that of a normal cell. B. Its nonpenetrating solute concentration is less than that of a normal cell. C. Its nonpenetrating solute concentration is equal to that of a normal cell. D. Its penetrating solute concentration is less than that of a normal cell. E. Its penetrating solute concentration is greater than that of a normal cell.

25. Which is true about neuronal membrane electrical and concentration gradients at the peak of the action potential? A. The electrical gradient is in a direction that would tend to move K+ out of the cell. B. The concentration gradient for K+ is in a direction that would tend to move it into the cell. C. The concentration gradient for K+ greatly increases compared to at rest. D. The concentration gradient for Na+ is in a direction that would tend to move it out of the cell. E. The electrical gradient for Na+ is in a direction that would tend to move it into the cell.

27. Heart rate is increased by the release of epinephrine by the adrenal medulla into the bloodstream. This is an example of A. endocrine control B. exocrine control C. paracrine control D. direct neural control E. positive feedback

27. Which of these is an example of a hypertonic solution? A. 200 mM NaCl B. 300 mM glucose C. 100 mM MgCl2 D. 400 mM urea E. 100 mM NaCl

29. The tall slender body shape that helps to dissipate heat in people native to equatorial regions is an example of A. an adaptation. B. acclimatization. C. set point resetting. D. homeostasis. E. phase-shift.

3. The study of disease states in the body is called A. Pathophysiology B. Anatomy C. Homeostasis D. Biology E. Histology

31. Neuronal axons typically have abundant A. voltage-gated channels for Na+ that open in response to depolarization. B. voltage-gated channels for K+ that open in response to hyperpolarization. C. receptor-mediated channels for Na+. D. receptor-mediated channels for K+. E. voltage-gated channels for Ca2+.

31. Two receptors, A and B, can bind the same chemical signaling molecules but the concentration of those molecules required to reach 50 percent saturation is twice as great for receptor B. Therefore the receptors have the same ________, but different ________. A. specificity, affinity B. specificity, saturation C. affinity, specificity D. affinity, competition E. competition, affinity

32. What is the location of the internal pacemaker that sets biological rhythms? A. suprachiasmatic nucleus of the brain B. ventricles of the heart C. endocrine gland in the gonads D. photoreceptors of the eye E. the adrenal glands

32. Which of the following statements regarding action potentials generated in a neuronal membrane is not true? A. Action potentials travel decrementally down the membrane. B. An action potential generates a new action potential in an adjacent area of membrane. C. An action potential generates a local current that depolarizes adjacent membrane to threshold potential. D. Action potentials are usually initiated at the initial segment of a neuron. E. An action potential generated by a threshold stimulus is the same size as one generated by a supra-threshold stimulus.

33. A protein is found in blood that is produced by the pancreas and acts on receptors of cells in the liver. What type of physiological regulator is it most likely to be? A. a hormone B. an autocrine signal C. a paracrine signal D. a neurotransmitter E. an enzyme

33. Which of the following statements concerning the properties of action potentials is true? A. The rate of propagation of an action potential down an axon is independent of stimulus strength. B. Action potentials can undergo summation. C. A supra-threshold stimulus can stimulate an action potential during the absolute refractory period. D. Action potentials generally propagate from the axon terminal toward the initial segment. E. Increasing the size of a stimulus will increase the amplitude of an action potential.

35. At any given time it is possible to see endocytotic vesicles docked to intracellular organelles such as those which may receive their contents for modification, synthesis, packaging, and then release. Which organelle would be most likely to be involved in this process as a destination for a transport vesicle formed for this purpose along the plasma membrane? A. Golgi apparatus B. peroxisome C. lysosome D. mitochondrion E. ribosome

36. Eating a bag of salty potato chips without increasing sodium excretion would result in what state? A. positive sodium balance B. negative sodium balance C. stable sodium balance D. It can't be determined without knowing the size of the sodium pool

38. What is the most common transport mechanism by which glucose and other organic solutes cross the luminal membrane of an epithelial cell layer? A. secondary active cotransport with Na+ B. glucose ATPase pump C. facilitated diffusion D. simple diffusion through the paracellular pathway E. through an ion channel

4. Which of the following statements regarding the diffusion of a nonpolar solute X across a cell membrane is correct? A. At equilibrium the net flux of X across the cell membrane is zero. B. At equilibrium, X will cease moving across the cell membrane. C. Solute X will be unable to reach equilibrium because it is nonpolar. D. Solute X will reach equilibrium, but the concentration will be much higher on the inside of the cell because of the smaller volume. E. At equilibrium, movement of X across the membrane will be much faster in one direction than in the other.

4. Which of these is a lipid soluble messenger? A. thyroid hormone B. protein kinase C. glucose D. sodium E. cyclic AMP

41. At an excitatory chemical synapse between two neurons, A. there is increased permeability of the postsynaptic cell to both Na+ and K+. B. a small hyperpolarization of the postsynaptic membrane occurs when the synapse is activated. C. an action potential in the presynaptic neuron always causes an action potential in the postsynaptic neuron. D. excitation occurs because K+ enters the postsynaptic cell. E. action potentials spread through gap junctions between cells.

42. When a reversible chemical reaction is at equilibrium A. the rate of the reaction in one direction is equal to the rate in the reverse direction. B. the concentration of the reactants is equal to the concentration of the products. C. both the forward and reverse reactions stop occurring. D. the supply of reactants has become exhausted, so the forward reaction ceases and the rate of the reverse reaction increases. E. catalysts no longer influence either the forward or reverse reaction rates.

44. An EPSP: A. is a direct result of the opening of ligand-gated channels permeable to both Na+ and K+ ions. B. is a direct result of the opening of voltage-gated channels permeable to both Na+ and K+ ions. C. stabilizes the membrane to remain at its resting potential. D. opens voltage-gated Ca2+ channels in the presynaptic membrane. E. occurs when voltage-gated Cl- channels open in a postsynaptic cell membrane.

45. At equilibrium, in an irreversible reaction: A. almost all of the reactants will have been converted to products. B. there will be an equal number of products and reactants. C. there will be very few molecules of product. D. small amounts of energy will have been released. E. large amounts of energy must have been input to reach that state.

45. Which best describes temporal summation? A. A synapse is stimulated a second time before the effect of a first stimulus at the synapse has terminated. B. It only refers to addition of EPSPs. C. Two synapses on different regions of a cell are stimulated at the same time. D. It always brings a postsynaptic cell to threshold. E. The size of an EPSP depends on the size of the stimulus.

46. What is the function of a catalyst in a chemical reaction? A. It lowers the activation energy of the reaction. B. It is split into individual molecules that are products of the reaction. C. It changes the energy content of the reactants. D. It generates heat that makes the reaction proceed. E. It ensures that the reaction can proceed only in one direction, from reactants to products.

47. Enzymes A. are catalysts in chemical reactions. B. can be carbohydrate molecules. C. are broken down during chemical reactions they catalyze. D. have names generally ending in the suffix "-ose." E. are polymers of ATP that store large amounts of energy.

49. What is a coenzyme? A. an organic cofactor that directly participates as one of the substrates in an enzymatic reaction B. a metal, such as zinc, that participates in enzymatic reactions C. a term regarding enzymatic reactions that is synonymous with "cofactor" D. any ligand that binds to a specific site on a protein receptor E. an inorganic molecule that catalyzes enzymatic reactions

52. Which of the following statements about acetylcholine is correct? A. Acetylcholine binds to nicotinic and muscarinic receptors. B. Acetylcholine binds to adrenergic receptors. C. Acetylcholine synthesis is catalyzed by acetylcholinesterase D. Acetylcholine is the neurotransmitter released by most sympathetic postganglionic neurons. E. Acetylcholine is generally transported back into presynaptic nerve terminals without being enzymatically degraded.

52. An experimental subject is isolated in an underground room with no windows, no clocks, and no contact with the outside world. Researchers monitoring his behavior observe that he eats breakfast a little bit later each day. What term best describes the subject's biological activity? A. circadian rhythm B. free-running rhythm C. jet lag D. phase shift E. entrainment

59. The reactions of the Krebs cycle: A. take place in the cytosol of human cells. B. generate ATP directly by substrate-level phosphorylation. C. are important for the metabolism of carbohydrates but not other molecules. D. take place only when no oxygen is present. E. produce pyruvate and lactate as end products.

6. Cocaine lowers the levels of a chemical messenger in the brain called enkephalin. Researchers have found the number of enkephalin receptors to be higher in cocaine addicts than nonaddicted people. This is an example of A. saturation. B. up regulation. C. antagonism. D. affinity. E. down regulation.

65. Which of the following kinds of neurons is not generally cholinergic? A. somatic motor neurons B. postganglionic sympathetic neurons C. postganglionic parasympathetic neurons D. preganglionic sympathetic neurons E. preganglionic parasympathetic neurons

68. Synthesis of neuropeptides differs from that of other neurotransmitters because it: A. takes place in the axon terminals of neurons. B. takes place in the cell bodies of neurons. C. takes place on ribosomes in the postsynaptic cell's membrane. D. uses amino acids as precursor molecules. E. only takes place at synapses outside the central nervous system.

7. What is the term for the developmental process that leads to specialized cell types? A. genomics B. differentiation C. homeostasis D. positive feedback E. acclimatization

9. At very low concentrations, epinephrine causes an artery to dilate. At higher concentrations epinephrine causes the same artery to constrict. How can these different effects be explained? A. There is one type of epinephrine receptor that uses two second messenger systems. B. There are two types of epinephrine receptors with different affinities for epinephrine that use two different second messenger systems. C. There are two types of receptors for epinephrine that use the same second messenger system. D. At higher concentrations epinephrine can pass through the plasma membrane and directly stimulate contraction within the cell.

1. What are the most common receptors for hydrophilic intercellular messenger molecules? A. peripheral membrane proteins B. integral membrane proteins C. specialized phospholipids within the membrane D. nucleic acids E. intracellular proteins

1. Which of these is NOT one of the four general categories of cells that make up the human body? A. epithelial cells B. collagen cells C. connective tissue cell D. neuron E. muscle cell

10. Which concept is the defining feature of the discipline of physiology? A. descent with modification B. homeostasis C. evolution D. dimorphism E. differentiation

12. In which of these would an injected drug be the most effective agonist for an endogenous chemical messenger? A. The drug has a lower affinity for the messenger's receptors than the messenger does. B. The drug achieves 50 percent saturation of the messenger's receptors at a lower concentration than that required by the messenger. C. The drug does not couple to the binding site of the messenger's receptor. D. The drug binds to an alternate binding site on the protein receptor and reduces its affinity for the endogenous chemical messenger.

15. Which of these would occur if the concentration of ATP were depleted in a typical nerve cell? A. Resting membrane potential would become more negative. B. Resting membrane potential would become less negative. C. The concentration gradient for Na+ would remain the same. D. The resting membrane potential would eventually become positive inside with respect to outside. E. There would be no change in the resting membrane potential.

16. Second messengers: A. are necessary for all receptor signal transduction mechanisms. B. act in the cell cytoplasm. C. only function as intercellular messengers. D. always function to activate enzymes. E. are always proteins.

16. Which situation describes a feedforward mechanism? A. Blood glucose returns toward normal an hour after a meal. B. The smell of rotten food on a plate triggers the vomit reflex. C. A drop in core body temperature triggers shivering. D. An increase in core body temperature stimulates sweating E. Food in the stomach triggers the production of stomach acid.

19. If the amount of sodium in the blood decreases, what would a negative feedback control mechanism be expected to do? A. Decrease the amount of sodium in the blood. B. Increase the amount of sodium in the blood. C. Leave the amount of sodium unchanged. D. Change the set point for sodium. E. Inhibit the ingestion of more sodium.

2. Physiology is the study of A. How two organisms interact B. How organisms function C. The spread of diseases D. The structure of the body

20. An action potential in a neuronal membrane differs from a graded potential in that: A. an action potential requires the opening of Ca2+ channels, whereas a graded potential does not. B. an action potential is propagated without decrement, whereas a graded potential decrements with distance. C. an action potential has a threshold, whereas a graded potential is an all-or-none phenomenon. D. movement of Na+ and K+ across cell membranes mediate action potentials, while graded potentials do not involve movement of Na+ and K+. E. action potentials vary in size with the size of a stimulus, while graded potentials do not.

20. What is a codon? A. a triplet of deoxyribonucleotides B. a triplet of ribonucleotides C. a sequence of ribonucleotides on tRNA D. a very small gene E. a very small genome

22. Which must happen in order for an action potential to begin? A. The membrane potential must be at the Na+ equilibrium potential. B. Na+ influx must exceed K+ efflux. C. The membrane must be out of the relative refractory period. D. Na+ channels must all be inactivated. E. Multiple inhibitory postsynaptic potentials (IPSPs) must summate.

23. The hormone insulin enhances the transport of glucose into body cells. Its secretion is controlled by a negative feedback system between the concentration of glucose in the blood and the cells that secrete insulin. Which of the following statements is most likely to be correct? A. A decrease in blood glucose concentration will stimulate insulin secretion, which will in turn lower the blood glucose concentration still further B. An increase in blood glucose concentration will stimulate insulin secretion, which will in turn lower the blood glucose concentration C. A decrease in blood glucose concentration will stimulate insulin secretion, which will in turn increase the blood glucose concentration D. An increase in blood glucose concentration will stimulate insulin secretion, which will in turn increase the blood glucose concentration still further

23. What is the term for the segments of primary RNA that are cleaved and discarded by spliceosomes? A. codons B. introns C. exons D. anticodons E. genes

23. Which describes the response of the voltage-gated channels when an axon is stimulated to threshold? A. K+ channels open before the Na+ channels. B. Na+ channels are activated and then inactivated. C. K+ channels open at the same time as the Na+ channels. D. K+ channels are opened when Na+ binds to the channel. E. K+ influx causes Na+ channels to inactivate.

24. During the rising (depolarizing) phase of a neuronal action potential, A. PK+ becomes much greater than PNa+. B. PNa+ becomes much greater than PK+. C. PK+ is the same as PNa+. D. Na+ efflux (flow out of the cell) occurs. E. K+ flows rapidly into the cell.

24. How are endocrine glands and hormones involved in homeostatic reflexes? A. Endocrine glands can be receptors, and hormones can be effectors. B. Endocrine glands can be integrators and hormones can be efferent pathways. C. Endocrine glands can be efferent pathways and hormones can be effectors D. Endocrine glands are not part of reflex mechanisms, but hormones can be afferent or efferent pathways E. They are not involved; reflexes only involve actions of the nervous system.

27. Which is the best definition of the term, ligand? A. a receptor composed of protein B. a molecule or ion that binds to a protein C. any molecule found in the intracellular fluid D. any molecule found in the extracellular fluid E. a carbohydrate molecule that binds weakly to membrane phospholipids

28. Which of the following solutions is not isotonic to human cells? A. 150 mM NaCl B. 300 mM urea C. 100 mM MgCl2 D. 300 mOsm NaCl

28. Which of the following statements about the phases of a neuronal action potential is true? A. During the after-hyperpolarization phase, the permeability of the membrane to sodium ions is greater than its permeability to potassium ions. B. During the after-hyperpolarization phase, the permeability of the membrane to potassium ions is greater than its permeability at rest. C. During the repolarizing phase, the permeability of the membrane to sodium ions is greater than its permeability to potassium ions. D. Potassium channels inactivate during the depolarization phase. E. Repolarizing to negative membrane potentials causes the sodium channels to inactivate.

3. A solute, X, is placed in compartment A of a two compartment container and allowed to diffuse to compartment B and attain diffusion equilibrium. At that point in time, A. there will be no further movement of any solute molecules between compartments. B. solutes will be moving in both directions equally. C. solutes will only continue to move from A to B. D. solutes will only continue to move from B to A. E. the concentration in compartment B will be much higher than that in compartment A.

3. The cell membrane is composed mainly of: A. cytosol. B. phospholipids and proteins. C. phospholipids and nucleic acids. D. water. E. proteins and glycocalyx.

30. Which of the following statements regarding endocytosis and exocytosis is correct? A. Endocytosis is a method by which large molecules may be secreted from a cell. B. Exocytosis is a method by which large molecules may be secreted from a cell. C. Pinocytosis is a form of endocytosis; phagocytosis is a type of exocytosis. D. Pinocytosis is a form of exocytosis; phagocytosis is a type of endocytosis. E. Pinocytosis and phagocytosis are both types of exocytosis.

32. What type of cellular transport involves the cytosolic protein clathrin? A. exocytosis B. receptor-mediated endocytosis C. primary active transport D. secondary active transport E. pinocytosis

32. Which describes the action of a ligand's competitive antagonist? A. It decreases the amount of ligand required to activate the protein. B. It blocks the binding of the ligand to its binding site and prevents activation of the protein. C. It binds to a different binding site on the protein, altering the protein shape so that a ligand cannot bind. D. When present, it increases the binding of a ligand to its receptor.

34. How is the strength of a stimulus encoded by neurons? A. by the size of action potentials B. by the frequency of action potentials C. by the duration of action potentials D. by whether the action potential peak is positive or negative

35. A burn patient ingests 100 grams of protein per day and loses 110 grams of protein per day due to the injury. What is the overall protein state of the patient? A. Positive protein balance B. Negative protein balance C. Stable protein balance D. A state that can't be determined

36. In skeletal muscle, when calcium binds to the regulatory protein troponin, it increases the affinity of neighboring troponin molecules for calcium. This is an example of A. allosteric modulation. B. cooperativity. C. covalent modulation. D. phosphorylation. E. saturation.

37. The regions of axon membrane that lie between regions of myelin are the A. islets of Langerhans. B. nodes of Ranvier. C. synaptic membranes. D. glial cells. E. dens of iniquities.

37. Which lists the epithelial cell barrier compartments in the order of the typical Na+ concentrations, from highest to lowest? A. intracellular, lumen side, blood side B. blood side, lumen side, intracellular C. blood side, intracellular, lumen side D. lumen side, intracellular, blood side E. lumen side, blood side, intracellular

4. Which is NOT a connective tissue cell? A. bone cells B. skeletal muscle cells C. blood cells D. fat cells E. cartilage cells

40. How does a chemical catalyst increase the rate of a reaction? A. by acting as one of the reactant molecules B. by decreasing the energy of activation C. by increasing the energy content of the product molecules D. by increasing the temperature of a solution E. by phosphorylating a reactant

41. With regard to reversible chemical reaction rates, which of the following statements is true? A. Decreasing the concentration of the reactants will increase the forward reaction rate. B. Increasing the temperature will increase the forward and reverse reaction rate. C. Increasing the activation energy will increase the forward reaction rate. D. Increasing the concentration of the products will increase the forward reaction rate. E. As a reaction progresses, the rate of the forward reaction increases as the concentration of reactants decreases.

42. An inhibitory postsynaptic potential: A. is produced by simultaneous increases in permeability to both Na+ and K+. B. occurs when a ligand-gated ion channel increases its permeability to K+. C. is a small depolarization in a postsynaptic cell. D. can be summed with other IPSPs to trigger an action potential in the postsynaptic cell. E. is produced by an increase in permeability to only Na+.

43. Which would be true about the following reaction? M + N Y + Z A. Adding a catalyst would alter the final concentrations of products and reactants at equilibrium. B. Starting at chemical equilibrium, increasing the concentration of M will transiently increase the rate of formation of Y and Z. C. Starting at chemical equilibrium, decreasing the concentration of M will increase the concentration of Y and Z. D. Both the reaction is reversible and at chemical equilibrium, increasing the concentration of M will drive the reaction to the left are correct E. Because the reactants and products are different molecules, this is not a reversible reaction.

44. Consider the reaction: H2CO3 CO2 + H2O + 4 kcal/mol. Which of the following is TRUE? A. The reaction is anabolic and the energy content of the reactant is greater than that of the products. B. The reaction is catabolic and the energy content of the reactant is greater than that of the products. C. The reaction is anabolic and the energy content of the products is greater than that of the reactant. D. The reaction is catabolic and the energy content of the products is greater than that of the reactant. E. The reaction is catabolic and the energy content of the products are equal to that of the reactant.

48. Which is TRUE about the initial segment of an axon? A. Its threshold potential is more positive than that of the cell body and dendrites. B. Its threshold potential is more negative than that of the cell body and dendrites. C. Synapses far from the initial segment are more effective in influencing whether an action potential will be generated in the axon than are synapses close to the initial segment. D. It is the region where neurotransmitter vesicles are docked and ready to be released by exocytosis. E. It can only conduct graded potentials because it lacks voltage-gated Na+ channels.

49. A presynaptic synapse: A. is a synapse between an axon terminal and a dendrite that can be either excitatory or inhibitory. B. is a synapse between an axon terminal and another axon's terminal that can be either excitatory or inhibitory. C. is any synapse onto a cell body, and they can be either stimulatory or inhibitory. D. is a synapse between an axon terminal and a dendrite of the same cell, which is always inhibitory. E. is a synapse between an axon terminal and another axon terminal that is always inhibitory.

5. What is the main function of cellular tight junctions? A. They resist forces that tend to pull cells apart. B. They form barriers that restrict the passage of materials through the extracellular space between cells. C. They are protein channels that allow the movement of ions between the cytosol of adjacent cells. D. They are spaces that allow movement of substances between the interior of the nucleus and the cytosol. E. They hold the genetic material in a tightly coiled conformation.

5. Which of the following is not true of glial cells? A. They form the myelin for axons. B. Neurons outnumber glial cells 10 to 1 in the nervous system. C. They deliver fuel molecules to neurons and remove the waste products of metabolism. D. They are important for the growth and development of the nervous system. E. They regulate the composition of the extracellular fluid in the CNS.

5. Which of the following would decrease the net flux of a penetrating solute into a cell? A. increasing the permeability constant for that solute B. decreasing the temperature C. increasing the concentration of the solute in the extracellular fluid D. increasing the area of the cell membrane E. decreasing the thickness of the membrane

50. Neuron X makes inhibitory axon-axon synaptic contact with neuron Y at the synapse of Y and neuron Z. Which will occur when action potentials are stimulated in neuron X? A. Neuron Y will be inhibited from reaching the threshold to fire an action potential. B. The release of neurotransmitter by neuron Y will be inhibited. C. The synapse between neurons Y and Z will be changed from an excitatory synapse to an inhibitory one. D. Neurons Y and Z will both be more likely to reach threshold and fire an action potential. E. Neurons Y and Z will both be less likely to reach threshold and fire an action potential.

10. Which is true about mediated transport across cell membranes? A. It refers to the movement of ions through protein channels. B. It refers both to simple diffusion and to the active transport of molecules. C. It is characterized by saturable carriers and a maximum velocity of transport. D. As the concentration gradient across a membrane increases, the transport rate always increases. E. It is nonspecific; any transporter can transport any molecule across the cell membrane.

10. With regard to the action of hormones and neurotransmitters on cellular receptors, which of these describes "amplification?" A. When the extracellular concentration of a chemical messenger reaches a very high level, it overwhelms transporter molecules and the chemical floods into the cell. B. Only hydrophilic first-messenger molecules can activate second messenger molecules within the cell cytosol. C. A single first messenger molecule activates multiple second messenger molecules, each of which activate thousands of enzymes. D. Some cellular receptors have such low affinity for chemical ligands that it can require a million or more molecules to activate them.

15. Neurons have a very prominent nucleolus which indicates that they are actively performing what function? A. making ATP B. synthesizing lipids C. manufacturing ribosomes D. breaking down carbohydrates E. dividing by mitosis

15. Which is NOT typically a step in the cAMP second-messenger system? A. A first-messenger binds to a transmembrane receptor. B. There is dissociation of G-protein subunits. C. An activated G-protein subunit phosphorylates cAMP-dependent protein kinase. D. Adenyl cyclase converts ATP into cAMP. E. Active cAMP-dependent protein kinase phosphorylates cell proteins.

16. What is the best description of a secondary active transport process that cotransports an amino acid with Na+? A. Both Na+ and the amino acid bind on the side of the membrane where the Na+ concentration is lowest, and undergo net movement to the other side of the membrane. B. Na+ and the amino acid bind to opposite sides of the membrane, and Na+ undergoes net transport from the side of the membrane with higher Na+ concentration toward the side with lower concentration, while the amino acid moves in the opposite direction. C. Both Na+ and the amino acid bind on the side of the membrane where the Na+ concentration is higher, and both are transported to the side of the membrane where the Na+ concentration is lower. D. Both Na+ and the amino acid bind to the side of the membrane where the amino acid concentration is highest and are transported toward the side of the membrane where the amino acid concentration is lower. E. Na+ and the amino acid bind to opposite sides of the membrane, and the amino acid undergoes net transport from the side of the membrane with lower Na+ concentration to the side of the membrane where the Na+ concentration is higher.

21. A threshold stimulus applied to an excitable membrane is one that is just sufficient to: A. trigger an excitatory postsynaptic potential. B. cause a change in membrane potential. C. trigger an action potential. D. be conducted to the axon hillock. E. depolarize a dendrite.

21. If pure water and a solution containing a nonpenetrating solute are separated by a membrane that is permeable only to water, what would occur? A. Water will diffuse by osmosis until the water concentrations in the two compartments become equal. B. Water will diffuse by osmosis until all of the the water is on the same side as the solute. C. Water will diffuse by osmosis toward the side with the solute, until stopped by opposing hydrostatic pressure. D. No movement will occur between the compartments. E. Water will diffuse by osmosis away from the side with the solute, until stopped by hydrostatic pressure.

21. Which one of the following is the correct sequence for a regulatory reflex arc? A. Stimulus, effector, efferent pathway, integrating center, afferent pathway, receptor B. Stimulus, receptor, efferent pathway, integrating center, afferent pathway, effector C. Stimulus, receptor, afferent pathway, integrating center, efferent pathway, effector D. Stimulus, effector, afferent pathway, integrating center, efferent pathway, receptor E. Effector, efferent pathway, integrating center, afferent pathway, receptor, stimulus

22. Identify the effectors in this homeostatic reflex: Eating a salt-rich meal increases blood volume and pressure, stretching blood vessel walls. Nerve signals sent to the brainstem stimulate changes in hormonal and neural signaling. The heart rate is slowed, blood vessel walls are relaxed, and the kidneys increase urinary salt. The blood pressure returns toward normal. A. brainstem and blood vessels B. blood vessels, hormones and nerves C. heart, kidneys and blood vessels D. brainstem, blood vessels, and kidneys E. hormones and nerves

22. RNA synthesis from a DNA template: A. is called translation of the message. B. requires DNA polymerase. C. is called transcription. D. occurs in the nucleolus. E. occurs in the cytoplasm.

22. What second messenger most directly causes calcium ions to be released from intracellular stores? A. diacylglycerol B. adenylyl cyclase C. inositol triphosphate D. phospholipase A E. phospholipase C

28. How is autocrine regulation best described? A. Chemical regulators are released directly into blood vessels. B. Chemical regulators released by cells affect the functional status of different kinds of cells in the vicinity of the secretory cell. C. Chemical regulators affect the same cells that produce them. D. Chemical regulators reach their site of action through a duct. E. Chemical regulators are continuously released in constant amounts by the cell.

29. A certain protein receptor is capable of binding the neurotransmitter epinephrine but does not bind to the neurotransmitters dopamine, glutamate, or serotonin. This is because the receptor displays what characteristic? A. saturation B. inhibition C. specificity D. acclimatization E. accommodation

29. Regarding the tonicity and osmolarity of solutions, which of the following statements is not true? A. The term "tonicity" refers to the effect that a solution has on the degree of stretch or shrinking of the cell membrane. B. The term "osmolarity" refers to the osmotic properties of a solution, regardless of its tonicity. C. Isotonic solutions are always isoosmotic. D. Hypoosmotic solutions are always hypotonic. E. Hypertonic solutions are always hyperosmotic.

3. Which of the following is not true about axon transport? A. It refers to the passage of materials from the cell body of a neuron to the axon terminals. B. It refers to the passage of materials from axon terminals to the cell body of a neuron. C. It refers to the transport of materials from the inside to the outside across the axonal membrane. D. It is especially important for maintaining the integrity of neurons with long axons.

30. After spending several days at a high altitude, where oxygen pressure is low, a person will begin to produce more red blood cells, which enhances the ability of blood to carry oxygen to the tissues. What term best describes this type of response? A. developmental acclimatization B. positive feedback C. physiological acclimatization D. feedforward regulation E. evolution

34. Once formed inside of the cell, most endocytic vesicles will fuse with which organelle for sorting? A. endoplasmic reticulum B. golgi apparatus C. endosome D. nucleus E. mitochondria

34. What is "allosteric modulation?" A. regulation of physiological functions by the sympathetic division of the autonomic nervous system B. modification of the functional state of a protein by temperature or pH C. the change in the shape and functional state of a protein that occurs when a ligand binds to a regulatory site D. the fact that all binding sites on a protein must be occupied to have a biological effect E. the ability of a single ligand-binding site to bind to molecularly similar ligands

35. Which of the following statements concerning the rate of action potential propagation is true? A. It is faster in small-diameter axons than in large-diameter axons. B. It is faster for a strong stimulus than for a weak one. C. It is faster in myelinated axons than in nonmyelinated axons. D. It is faster in the dendrites than in the axon. E. It occurs at the same rate in all axons, regardless of their diameter.

36. Which of the following statements about epithelial cells and epithelial transport is NOT correct? A. Epithelial cell membranes express different transport proteins on different cell surfaces. B. Epithelial cells lining the small intestine have Na, K-ATPase pumps only in their basolateral membranes. C. The plasma membrane of epithelial cells that faces the inside of a hollow or fluid-filled chamber in the body is called the basolateral membrane. D. The pathway taken by substances that flow between epithelial cells is called the paracellular pathway. E. When substances cross epithelial barriers by going through the cell membranes and cytosol, it is called the transcellular pathway.

39. Exocytosis of neurotransmitter into the synaptic cleft is triggered by an influx of ______ in response to the arrival of an action potential in the axon terminal. A. K+ B. Na+ C. Ca2+ D. ATP E. Cl-

40. The main role of calcium ions at chemical synapses is to A. depolarize the axon terminal of the presynaptic cell. B. bind to neurotransmitter receptors on the postsynaptic cell. C. cause fusion of synaptic vesicles with the plasma membrane of the axon terminal. D. interfere with IPSPs in the postsynaptic cell. E. diffuse across the synaptic space and enter the postsynaptic cell.

46. A postsynaptic neuron has three presynaptic inputs - from neurons X, Y, and Z. Stimulation of neuron X causes the postsynaptic neuron to depolarize by 0.5 mV. When X and Y are stimulated simultaneously, the postsynaptic neuron depolarizes by 1 mV. When X and Z are stimulated simultaneously, however, there is no change in the membrane potential of the postsynaptic neuron. What is most likely true about presynaptic neurons Y and Z? A. They are both excitatory. B. They are both inhibitory. C. Y is excitatory and Z is inhibitory. D. Z is excitatory and Y is inhibitory.

47. A postsynaptic neuron has three presynaptic inputs - from neurons X, Y, and Z. When X and Y are stimulated simultaneously and repeatedly, the postsynaptic neuron reaches threshold and undergoes an action potential. When X and Z are stimulated simultaneously, however, there is no change in the membrane potential of the postsynaptic neuron. The simultaneous stimulation of X and Y is an example of A. temporal summation. B. presynaptic inhibition. C. spatial summation. D. neuronal divergence. E. presynaptic facilitation.

5. The process whereby repeated exposure to a hormone can cause a decrease in the number of receptors for that hormone is called A. competition. B. inhibition. C. down regulation. D. antagonism. E. saturation.

5. What is the principal function performed by epithelial cells? A. fat storage B. anchoring body structures C. forming boundaries between body compartments D. generating movement E. transmitting electrical signals

51. In order to increase the overall rate of a metabolic pathway consisting of five reactions catalyzed by five different enzymes, which must occur? A. increasing the reaction rate of all five enzymes B. increasing the reaction rate of the fastest enzyme C. increasing the reaction rate of the slowest enzyme D. increasing the reaction rate of the first enzyme in the pathway E. increasing the reaction rate of the last enzyme in the pathway

51. Which of the following is not known to be an important neurotransmitter in the CNS? A. Dopamine B. Acetylcholine C. Morphine D. Glutamate E. Substance P

52. ATP is A. formed during the hydrolysis of ADP. B. used by cells for the storage of energy. C. used to transfer energy within a cell. D. a protein. E. a molecule with less total energy content than ADP.

53. Which equation is most accurate? A. extracellular fluid volume + interstitial fluid volume = whole body fluid volume B. intracellular fluid volume + interstitial fluid volume = extracellular fluid volume C. extracellular fluid volume - interstitial fluid volume = plasma volume D. plasma volume + intracellular fluid volume = extracellular fluid volume E. total body fluid volume - intracellular fluid volume = interstitial fluid volume

55. Which is TRUE about glycolysis? A. It does not occur in the absence ofO2. B. It does not occur in the presence of O2. C. It may result in the formation of two molecules of lactate for each molecule of glucose. D. It is a series of metabolic reactions that occur mainly inside the inner membrane of a mitochondrion. E. It is a metabolic reaction in which glucose is manufactured from large carbohydrates like glycogen.

57. Nicotine is: A. a cholinergic antagonist. B. a beta-adrenergic agonist. C. a cholinergic agonist. D. an alpha-adrenergic antagonist. E. a neurotransmitter.

59. Alzheimer's disease is thought to involve primarily: A. loss of neurons that secrete or respond to catecholamines. B. loss of adrenergic neurons. C. loss of cholinergic neurons. D. loss of neurons that secrete or respond to dopamine. E. tumors that produce excess serotonin.

6. Equal amounts of two solutes, A and B, are placed into the same beaker of water at the same time. Solute A reaches diffusion equilibrium faster than solute B. What is the most likely explanation for this observation? A. The temperature was greater for solute A than solute B. B. The concentration gradient for A was greater than B. C. Solute A is smaller than solute B. D. Solute A traveled a shorter distance than solute B. E. Solute B is more soluble in water than solute A.

60. Which is a series of reactions by which fatty acid catabolism occurs? A. glycolysis B. lipogenesis C. beta-oxidation D. glycogenolysis E. phosphorylation

62. Most energy in the body is stored in what form? A. ATP B. glucose C. fat D. protein E. DNA

63. Ammonia is A. a waste product of fatty acid metabolism. B. exhaled by the lungs into the air. C. processed by the liver to form urea, a less toxic compound. D. a waste product of fatty acid metabolism and is excreted by the kidneys into urine. E. a polypeptide containing many amino acids.

67. Drug X interferes with the action of norepinephrine at synapses. Which of the following mechanisms would not explain the effects of X? A. X inhibits synthesis of norepinephrine at the axon terminal. B. X inhibits norepinephrine release from the terminal. C. X blocks reuptake of norepinephrine by the terminal. D. X is an adrenergic receptor antagonist. E. X stimulates the catabolism of norepinephrine.

7. According to the equation expressed as Ohm's law, which of these would cause the greatest increase in current? A. doubling both voltage and resistance B. reducing both voltage and resistance by half C. doubling voltage and reducing resistance by half D. reducing voltage by half and doubling resistance E. quadrupling both voltage and resistance

7. Protein channels that link the cytosol of adjacent cells are called ___________ junctions. A. cadherin B. tight C. gap D. conjunction E. nexus

71. The ________________ is best described as "an interconnected group of brain structures including parts of the frontal lobe-cortex, temporal lobe, thalamus, and hypothalamus, that is associated with learning, emotional experience, and behavior?" A. diencephalon B. cerebrum C. limbic system D. reticular formation E. cerebellum

8. The permeability of the plasma membrane to mineral ions: A. is not influenced by channels formed by proteins. B. is the same in all cell types. C. is affected by differences in electrical charge on the two sides of the membrane. D. is zero in all living cells. E. is only possible because of the hydrophobic interior of the lipid bilayer.

9. If a person begins to sweat upon entering a hot room but continued sweating is able to keep the body temperature constant, which of these best describes her condition? A. She is in an equilibrium state. B. She is not using energy to maintain a constant temperature. C. She is in a steady state D. She is using a positive feedback mechanism.

9. Ion channels in cell membranes: A. are nonspecific. B. are not affected by differences in electrical potential across the membrane. C. may open in response to binding a ligand. D. only allow ions to move from the extracellular fluid into the cell. E. only allow ions to move from the intracellular fluid out of the cell.

11. The membrane potential of most neurons at rest is: A. equal to the equilibrium potential for potassium. B. equal to the equilibrium potential for sodium. C. slightly more negative than the equilibrium potential of potassium ion. D. more positive than the equilibrium potential for potassium. E. more positive than the equilibrium potential for sodium.

12. Which of the following situations best represents a homeostatic mechanism? A. A person who becomes very nervous begins to sweat profusely. B. After going outside on a hot day, the core body temperature increases. C. Increasing the size of fast food restaurant portions causes body weight to increase. D. After eating a large batch of salty popcorn, levels of salt in the urine increase. E. As age increases, the amount of calcium in bones tends to decrease.

13. A fat cell responds to the presence of the hormone epinephrine by increasing cytosolic cyclic AMP production, which leads to the catabolism of both glycogen and fat. What is the most likely explanation for this phenomenon? A. Epinephrine is binding to two types of receptors in the plasma membrane. B. The activated receptor complex stimulates production of two different second messengers. C. Cyclic AMP directly activates two kinds of enzymes. D. Cyclic-AMP-dependent protein kinase activates two kinds of enzymes.

14. Which is a form of cellular transport that involves the movement of molecules into cells without passing through the plasma membrane's structural matrix? A. diffusion B. osmosis C. facilitated diffusion D. endocytosis E. apoptosis

17. What is the general purpose of positive feedback mechanisms? A. to maintain a constant internal environment B. to anticipate changes in the environment C. to return a variable toward the set point D. to bring about a rapid change in the body E. to detect changes in the external environment

18. A cell is placed into a 1 millimolar solution of substance X and over time you witness the concentration of X inside the cell increase to 5 millimolar. What is the best explanation for this observation? A. X is moving into the cell by simple diffusion. B. X is moving into the cell by diffusion through a protein channel. C. X is moving into the cell by facilitated diffusion. D. X is moving into the cell by primary active transport. E. Water is leaving the cell by osmosis.

18. Which is true about the structure and function of a gene? A. It is an uncoiled protein that contains information necessary for the synthesis of other proteins. B. It is a sequence of nucleotides in DNA that acts as an enzyme to digest proteins. C. It is composed of many molecules of DNA and contains information needed to make RNA. D. It is a sequence of nucleotides in DNA that contains information necessary for the synthesis of proteins.

18. Which of the following statements concerning the permeability of a typical neuron membrane at rest is true? A. The permeability to Na+ is much greater than the permeability to K+. B. All of the K+ channels in the membrane are open. C. The voltage-gated Na+ channels are in the inactivated state. D. Most of the voltage-gated Na+ channels are in the closed state. E. There is equal permeability to Na+ and K+.

19. Amplification during a second messenger cascade is beneficial because amplification: A. takes small molecules and makes polymers out of them. B. results in the production of more of the first messenger. C. allows a cell to respond to more different hormones. D. allows small amounts of hormones to produce large responses in target cells.

2. Which is NOT a feature of the fluid-mosaic model of plasma membranes. A. Integral membrane proteins are embedded in the membrane. B. Phospholipids form a bilayer. C. Cholesterol associates with phospholipid molecules. D. Carbohydrates are linked to lipids and proteins on the interior surface, forming a glycocalyx layer. E. Peripheral membrane proteins associate with polar regions of integral membrane proteins.

2. Which is not true of myelin? A. It is a fatty membranous sheath. B. It is formed by glial cells. C. It influences the velocity of conduction of an electrical signal down an axon. D. It covers all parts of the neuron, including the axon, cell body, and dendrites.

20. "Osmosis" refers to the movement of what substance across semipermeable membranes? A. glucose B. charged particles C. lipid molecules D. water E. solutes

21. What codon corresponds to the DNA sequence G-T-A? A. G-T-A B. A-T-G C. C-A-T D. C-A-U E. T-A-C

24. What will happen if a normal cell is placed in a hyperosmotic solution? A. It will swell in size. B. It will shrink in size. C. It will stay the same size. D. It may swell, shrink, or stay the same size, depending upon the concentration of penetrating and nonpenetrating solutes in the solution.

24. Which is a function of transfer RNA (tRNA)? A. transport smRNA out of the nucleus B. binding specifically to mRNA and nonspecifically to amino acids C. binding specifically to amino acids and nonspecifically to mRNA D. binding specifically to both mRNA and to amino acids

26. Some neurons in the vagus nerve have synaptic connections to sinoatrial (pacemaker) cells in the heart. These neurons secrete acetylcholine, which ultimately results in a decreased heart rate. This is an example of A. endocrine control B. exocrine control C. hormonal control D. neural control E. paracrine control

26. Why do solutions for injection or infusion into people with low blood volume normally contain 150 mM NaCl? A. This is a hypotonic solution, which will cause water movement into dehydrated blood cells. B. This is an isotonic solution, and the water in it will follow Na and Cl into the the intracellular fluid compartment. C. This is a hypertonic solution, which will raise the blood volume and pressure more rapidly than an isotonic solution would. D. This is an isotonic solution, and NaCl will keep the added volume in the extracellular fluid compartment. E. NaCl are penetrating solutes, which will get them more quickly into blood cells to increase their volume.

27. Why are action potentials sometimes described as being "all-or-none" in character? A. The rate of propagation of an action potential down an axon is independent of stimulus strength. B. They are associated with an absolute refractory period. C. A supra-threshold stimulus is required to stimulate an action potential during the relative refractory period. D. An action potential occurs whenever a suprathreshold stimulus occurs, and its amplitude does not vary with the size of a stimulus. E. Action potentials are always the same size, even when ion gradients vary in size.

28. Which is NOT true about a binding site on a protein? A. It is an area of the protein with a shape complementary to that of a ligand. B. It is determined by the amino acid sequence of the protein. C. The binding of a ligand to a binding site typically changes the conformation of the protein. D. There can only be one binding site on a given protein. E. Binding of a ligand to the binding site typically activates or inactivates a protein's specific function.

30. The relative refractory period of an axon coincides with the period of A. activation and inactivation of voltage-dependent Na+ channels. B. Na+ permeability that is greater than that during the depolarization phase. C. increased K+ flux into the cell. D. increased K+ permeability of the cell. E. Increased Na+ flux through K+ channels.

31. Which form of endocytosis is nonspecific, in that it occurs by the formation of an invagination of the plasma membrane, which then fills with interstitial fluid of the immediate area? A. active transport B. hyperosmotic vesicular entrapment C. phagocytosis D. pinocytosis E. hydrosmosis

33. What is the defining characteristic of an allosteric protein? A. They contain two polypeptide chains, with each being an exact mirror image of the other. B. They contain only one ligand-binding site, but because the specificity is low, many different ligands can bind to it. C. They contain two ligand-binding sites, one that activates the protein when a ligand binds, and the other that inactivates the protein when the same ligand binds. D. They contain more than one ligand-binding site, and noncovalent binding of a ligand to one site alters the shape of other ligand binding sites. E. They contain no binding sites of their own, but act by modulating the activity of other proteins.

34. Which best describes how the total body balance of any chemical substance is determined? A. the rate the body produces the substance B. the rate the substance is secreted from the body C. the rate the substance is metabolized by the body D. the difference between the amount of substance lost from the body and the amount gained the body E. the amount produced by the body minus the amount metabolized by the body

35. Which of these covalently modifies proteins by phosphorylation? A. enzymes called protein phosphatases B. other proteins called allosteric proteins C. any ligand which can bind to specific binding sites D. enzymes called protein kinases E. metal ions, such as Fe2+

38. Which is FALSE about interneurons? A. They receive synaptic input from other other neurons in the CNS. B. They sum excitatory and inhibitory synaptic inputs. C. They deliver synaptic input on other neurons. D. They make synapses on effector organs in the PNS. E. They can transmit information between afferent neurons and efferent neurons.

48. Which is NOT true about cofactors involved in enzymatic reactions? A. They may alter the conformation of the enzyme. B. They may be a metal such as iron. C. They may be a substrate in a catalyzed reaction. D. There must be equal quantities of enzyme and cofactor molecules for a reaction to proceed. E. Only a small number of cofactor molecules may be needed to maintain enzyme activity.

50. Which of the following is true concerning the rate-limiting step in a metabolic pathway? A. It is likely to be the slowest reaction in the pathway, and it is always the last step in a metabolic pathway. B. It is likely to be the fastest reaction in the pathway, and it is always the last step in a metabolic pathway. C. It is always the first step in the pathway, and may be subject to end-product inhibition. D. It is likely to be the slowest reaction in the pathway and it may be subject to end-product inhibition. E. It is likely to be the fastest reaction in the pathway and it may be subject to end-product inhibition.

57. What are the products of glycolysis under anaerobic conditions? A. 2 molecules of NADH and 2 molecules of water B. 2 molecules of pyruvate, 2 molecules of lactate, and 2 ATP C. 2 molecules of pyruvate and 36 molecules of ATP D. 2 molecules of ATP, 2 molecules of water, and 2 molecules of lactate E. 2 molecules of pyruvate, 2 molecules of water, and 2 NADH

6. The cell type that is specialized to communicate with other cells and control their activities is A. Epithelial cells B. Muscle cells C. Connective tissue cells D. Nerve cells

60. Which is one of the major inhibitory neurotransmittors in the CNS? A. Glutamate B. Dopamine C. Norepinephrine D. Gamma-aminobutyric acid (GABA) E. Beta-endorphin

63. The portion of the peripheral nervous system that is composed of nerve fibers that innervate skeletal muscle is called the: A. afferent nervous system. B. sympathetic nervous system. C. parasympathetic nervous system. D. somatic motor nervous system. E. autonomic nervous system.

64. Before an amino acid can be broken down for energy: A. the side chain must be removed. B. the carboxyl group must be removed. C. it must be converted to NAD+. D. the amino group must be removed. E. it must be phosphorylated.

69. Which best describes the reticular formation of the brain? A. It is mainly involved in motor coordination and balance. B. It is the master endocrine gland of the brain. C. It is primarily responsible for visual perception. D. It integrates information from all regions of the CNS, and incorporates the mechanisms that regulate sleep and wakefulness. E. It is the primary synaptic relay station for sensory information entering the CNS.

7. In general, polar molecules diffuse more rapidly through the lipid bilayer part of cell membranes than do nonpolar molecules. This statement is: A. true. B. false, because polar molecules diffuse through less rapidly because the bilayer is polar throughout its width. C. false, because polar molecules diffuse through less rapidly because the bilayer is nonpolar throughout its width. D. false, because nonpolar molecules diffuse through more rapidly because much of the bilayer is nonpolar. E. false, because the rate of diffusion of nonpolar and polar molecules through the bilayer is essentially the same as long as the molecules are the same size.

74. Postganglionic neuron cell bodies of the autonomic nervous system have which category of neurotransmitter receptor? A. Adrenergic receptor B. Serotonin receptors C. Muscarinic acetylcholine receptors D. Nicotinic acetylcholine receptors E. Dopamine receptors

8. Compartments A and B are separated by a membrane that is permeable to K+ but not to Na+ or Cl-. At time zero, a solution of KCl is poured into compartment A and an equally concentrated solution of NaCl is poured into compartment B. Which would be true once equilibrium is reached? A. The concentration of Na+ in A will be higher than it was at time zero. B. Diffusion of K+ from A to B will be greater than the diffusion of K+ from B to A. C. There will be a potential difference across the membrane, with side B negative relative to side A. D. The electrical and diffusion potentials for K+ will be equal in magnitude and opposite in direction. E. The concentration of Cl- will be higher in B than it was at time zero.

8. Epinephrine activates the cyclic AMP pathway in liver cells. In this example, epinephrine is a ____________ and cAMP is a _____________. A. ligand, receptor B. first messenger, hydrophobic hormone C. second messenger, ion channel D. first messenger, second messenger E. enzyme, second messenger

8. Which best describes the extracellular matrix? A. It is found just inside the cell membrane in all tissues, it sends branching collagen fibers between cells to connect them, and it transmits chemical information from the interior of one cell to the interior of adjacent cells. B. It is a tissue having more than the four general cell types, it transports proteins and polysaccharides between body compartments, and it is the route by which chemical signals like hormones reach all parts of the body. C. It covers the body's surface, it contains connective and muscle tissue, and it helps generate movement. D. It surrounds cells, it contains proteins, polysaccharides and minerals, it provides a scaffold for cell attachment, and it transmits chemical messengers to cells.

11. Describing a physiological variable as "homeostatic," means that it A. has varied from the normal value, and will remain constant at the new value. B. never varies from an exact set point value. C. is in an equilibrium state that requires no energy input to stay at the normal value. D. is in a state of dynamic constancy that is regulated to remain near a stable set point value. E. has no normal range, but will just change to match the outside environmental conditions.

1. Which is a major function of the plasma membrane? A. storing calcium ions B. storing organic chemicals for metabolism C. providing genetic information D. generating ATP E. regulating the passage of molecules into and out of the cell

1. Which of the following is/are functions of the human nervous system? A. receiving, storing, and processing information on the internal and external environments B. bringing about changes in physiology and/or behavior to ensure optimal functions of homeostatic mechanisms C. secretion of hormones D. coordination of movement E. All of the choices are correct.

11. Which organelles would you expect to be especially numerous in cells that utilize oxygen to generate a great deal of energy in the form of ATP? A. peroxisomes B. endosomes C. lysosomes D. ribosomes E. mitochondria

12. Which of the following is a feature that distinguishes active transport from facilitated diffusion? A. saturation of transport rate B. requirement for a carrier molecule C. carrier molecules have specificity D. presence of a transport maximum E. requirement for metabolic energy

12. Which of these are functions of the Golgi apparatus? A. modifying proteins synthesized on free ribosomes and storing calcium ions B. digestion of engulfed bacteria and using oxygen to generate ATP C. synthesizing lipids and intracellular storage of calcium ions D. modifying proteins synthesized on free ribosomes and allowing the distribution of modified proteins throughout the cell in vesicles E. modifying proteins synthesized on ribosomes associated with granular endoplasmic reticulum and allowing the distribution of modified proteins throughout the cell in vesicles

14. Which of components of a general reflex arc are listed in the order information typically flows through them following a stimulus? A. effector, afferent pathway, integrating center, efferent pathway, receptor B. effector, efferent pathway, integrating center, afferent pathway, receptor C. integrating center, receptor, afferent pathway, efferent pathway, effector D. receptor, efferent pathway, integrating center, afferent pathway, effector E. receptor, afferent pathway, integrating center, efferent pathway, effector

15. By what transport mechanism does glucose enter most cells? A. diffusion through the lipid bilayer B. primary active transport C. secondary active transport D. diffusion through a protein channel E. facilitated diffusion

16. Which is FALSE about the equilibrium potential of a given ion across a membrane? A. It is a function of the concentration of that ion on both sides of the membrane. B. It is the potential at which there is no net movement of that ion across the membrane. C. It is the potential difference across the membrane at which an electric force favoring movement of the ion in one direction is equal in magnitude and opposite in direction to the diffusion force provided by the concentration difference of the ion across the membrane. D. A permeable ion will move in the direction that will tend to bring the membrane potential toward that ion's equilibrium potential. E. An anion that is in higher concentration inside the cell than outside the cell will have a negative eqilibrium potential.

17. Which of the following statements about the Na+-K+ ATPase pump is false? A. It transports Na+ out of cells and K+ into cells. B. It binds to, and hydrolyzes, ATP. C. It is constantly active in all cells. D. Its activity requires the expenditure of metabolic energy. E. It transports Na+ and K+ in a 1:1 ratio.

18. Shivering in response to a cold draft is an example of A. A homeostatic mechanism B. Negative feedback C. A physiological reflex D. Thermoregulation E. All of the choices are correct

19. What is a genome? A. a cluster of genes that are all regulated in the same manner B. a measure of the genetic variability in a population C. a region of DNA that codes for a single protein D. all of the protein in a cell at a given point in time E. the total genetic information in a typical cell of an organism

19. Which is NOT an example of a graded potential? A. a receptor potential in a sensory receptor cell B. a depolarizing excitatory postsynaptic potential (EPSP) C. a hyperpolarizing inhibitory postsynaptic potential (IPSP) D. a depolarizing pacemaker potential E. a depolarizing action potential

2. Specificity is an important characteristic of intercellular communication; which of these best explains why it occurs? A. because all cells have very similar compositions of their phospholipid membranes B. because protein receptors are only located on the surface of target cells C. because all cells have the same DNA, so any cell can express protein receptors for a specific chemical D. because chemical messengers are all proteins E. because protein receptors for chemical messengers are only expressed in specific target cells

20. Amplification of a second messenger cascade can take place at which level of a signal cascade? A. One activated receptor can activate numerous G-proteins. B. One activated G-protein can activate numerous effector enzymes. C. One active effector enzyme can catalyze numerous reactions. D. One activated protein kinase can allosterically modulate numerous proteins. E. All of the choices are correct.

20. What is the best description of the efferent pathway of a reflex arc? A. signals from the integrating center to receptors B. the route by which receptors send signals to effectors C. signaling pathway for receptors to influence the integrating center D. the route by which effector organs send signals to receptors E. the route by which signals from an integrating center reach effector organs

21. What is a role of calcium ions in the second messenger cascade involving phospholipase C, diacylglycerol, and inositol trisphosphate? A. It splits and activates G-protein subunits. B. It binds to the endoplasmic reticulum and causes the release of inositol trisphosphate. C. It phosphorylates cell proteins. D. It is the first messenger that binds to the integral membrane protein receptor. E. Along with diacylglycerol, it activates protein kinase C.

25. What is a hormone? A. a chemical released from a nerve cell that affects nearby cells across a synapse B. a chemical released from an endocrine gland that affects target cells without entering the bloodstream C. a chemical found in the blood that catalyzes the destruction of ingested toxins and foreign substances D. a chemical excreted from sweat gland that signals other individuals about the physiological status of the body E. a chemical regulator secreted from an endocrine gland that travels through the bloodstream to affect target cells

26. Which is NOT a function of the Golgi apparatus? A. sorting of proteins destined for various locations in the cell B. modifying proteins destined for secretion C. packaging enzymes destined for lysosomes D. addition of carbohydrate groups to proteins E. transcribing a signal sequence onto proteins destined for secretion

26. Which is most directly responsible for the falling (repolarizing) phase of the action potential? A. Voltage-gated Na+ channels are opened. B. The Na+, K+ pump restores the ions to their original locations inside and outside of the cell. C. The permeability to Na+ increases greatly. D. ATPase destroys the energy supply that was maintaining the action potential at its peak. E. The permeability to K+ increases greatly while that to Na+ decreases.

29. Which of the following statements about the refractory period of a membrane is true? A. The absolute refractory period refers to the period of time during which another action potential cannot be initiated in that part of the membrane that is undergoing an action potential, no matter how great the strength of the stimulus. B. The relative refractory period refers to the period of time during which another action potential can be initiated in that part of the membrane that has just undergone an action potential if a stronger than normal stimulus is applied. C. The refractory period prevents the action potential from spreading back over the part of the membrane that just underwent an action potential. D. The refractory period places an upper limit on the frequency with which a nerve cell can conduct action potentials. E. All of the above choices are correct.

3. Which of the following are ways in which binding of an intercellular chemical messenger with a cell's receptor can bring about a cellular response? A. opening or closing of specific ionic channels in the plasma membrane B. activation of an intracellular second-messenger system C. promoting or inhibiting the transcription of genes that code for the synthesis of cellular proteins D. activating or inhibiting intracellular enzymes E. All of the choices are correct.

30. A solution containing proteins of a particular type is exposed to the same concentrations of ligands X and Y, but the percent saturation of molecule X is greater than the percent saturation of molecule Y. Which is most likely to be a true statement? A. The binding sites for ligand X are 100% saturated. B. The binding sites for ligand X have greater specificity than the binding site for ligand Y. C. Ligand X must be a competitive inhibitor of ligand Y. D. Both ligands must bind to the same binding site on the protein. E. The protein has a higher affinity for ligand X than for ligand Y.

31. Circadian rhythms are biological rhythms with what main characteristic? A. They are cyclical, like the 28-day female menstrual cycle. B. They are cyclical, like the rhythmic beating of the heart. C. They are voluntary rhythms, like the time you decide to eat lunch each day. D. They cease to occur when a person is in a dark environment. E. They repeat approximately every 24 hours, like daily spikes in hormone secretion.

33. What process lowers blood plasma levels of cholesterol-containing lipoproteins? A. second messenger-activated, sterol transgenesis B. hydrophobic phagocytosis C. simple, transcellular membrane diffusion D. Na+ gradient-dependent, secondary active transport E. clathrin-dependent, receptor-mediated endocytosis

36. An action potential does not re-stimulate the adjacent membrane that was previously depolarized because A. stimulation is inhibited by the myelin sheath. B. it is impossible for an action potential to be propagated along an axon toward the nerve cell body. C. the resting membrane potential of the axon is too positive. D. the resting membrane potential of the axon is too negative. E. that area of the membrane is in the absolutely refractory period.

37. Which is NOT true about protein kinases? A. They add phosphate groups to proteins. B. They produce effects similar to allosteric modulation. C. They perform the opposite function as phosphatases. D. They use ATP to carry out their reactions. E. They remove phosphate groups from proteins.

38. The term "metabolism:" A. is synonymous with the term "catabolism." B. is synonymous with the term "anabolism." C. refers to any chemical reaction that involves the production of energy. D. is defined as the covalent modification and activation of a protein with binding sites for organic molecules. E. refers to the synthesis and breakdown of organic molecules involved in cell structure and function.

39. The probability of a reaction occurring is increased A. by decreasing reactant concentrations. B. by increasing the activation energy. C. by increasing the concentration of any of the products. D. if the reaction uses a great deal of energy. E. if the concentration of one of the reactants increases.

4. What feature of phospholipids allows them to interact with aqueous cytosol and extracellular fluid, while still presenting a barrier to hydrophilic substances? A. They are polar molecules. B. They are nonpolar molecules. C. They are lipids. D. They are extremely rigid molecules. E. They are amphipathic molecules.

4. Which is FALSE about neurons? A. A given neuron can be either a presynaptic neuron or a postsynaptic neuron. B. An individual neuron can receive information from multiple other neurons. C. An individual neuron can transmit information to multiple other neurons. D. A neuron can simultaneously release more than one type of neurotransmitter. E. A neuron receives information on its axons and delivers it to other neurons through its dendrites.

43. Which of the following statements about EPSPs is false? A. They are produced by the opening of chemically-gated sodium channels. B. They transmit signals over relatively short distances. C. They depolarize postsynaptic cell membranes. D. They are able to summate. E. They are always the same amplitude.

53. The site where most of the ATP is generated in a cell is the A. nucleus. B. plasma membrane. C. endoplasmic reticulum. D. Golgi apparatus. E. mitochondria.

54. Acetylcholine is the main neurotransmitter released by: A. preganglionic sympathetic neurons and cells of the adrenal medulla. B. cells of the adrenal medulla and postganglionic parasympathetic neurons. C. motor neurons and postganglionic sympathetic neurons. D. preganglionic sympathetic neurons and postganglionic sympathetic neurons. E. preganglionic sympathetic neurons and motor neurons.

55. Which of the following statements about norepinephrine is FALSE? A. Norepinephrine is a neurotransmitter. B. Norepinephrine binds to adrenergic receptors. C. Norepinephrine is a catecholamine. D. Dopamine is a precursor to norepinephrine. E. Epinephrine is a precursor to norepinephrine.

6. What are desmosomes? A. low-resistance channel-like passages that let ions travel between the interiors of adjacent cells B. cell organelles that contain enzymes for digesting cellular debris and foreign microbes C. cellular organelles that transcribe RNA into DNA D. membrane-bound vesicles that pinch off from the plasma membrane and enter the cell E. dense plaques of proteins that maintain firm attachments between adjacent cells

61. Which is NOT true about fatty acid synthesis? A. takes place in the cytosol of cells B. results in molecules with an even number of carbon atoms only C. requires more energy than is produced by the catabolism of the same fatty acid D. begins with a molecule of actetyl coenzyme A E. The enzymes that catalyze it are in the same location as those that mediate fatty acid catabolism.

62. The central nervous system includes the: A. afferent nerves and spinal cord. B. efferent nerves and spinal cord. C. autonomic nervous system and the brain. D. brain stem and the autonomic nervous system. E. brain and spinal cord.

64. The region of the brain that is the most important control area for homeostatic regulation of the internal environment is: A. the thalamus. B. the hippocampus. C. the cerebrum. D. the cerebellum. E. the hypothalamus.

9. Which best describes functions of the agranular (smooth) endoplasmic reticulum? A. transcription of DNA into RNA B. generation of ATP C. digestion of engulfed bacteria and cellular debris D. synthesis and packaging of proteins for secretion from the cell or export to other organelles E. synthesis of lipids and intracellular storage of calcium ions

35) Sarah is a girl with dreams of becoming an Olympic marathon runner. She just learned that she has a rare genetic mutation and does not produce functional creatine phosphate. What portion of Sarah's marathon experience will be effected? A) Just the first few seconds of exercise B) All muscle contractions after Sarah reaches her maximum heart rate (about 10 minutes into her run) C) All muscle contractions after Sarah reaches fatigue (about an hour into her run) D) Every moment of Sarah's runs E) No effects on her running

11) Elizabeth had heart surgery to repair the pacemaker of her heart. Into which structure did the surgeon need access? A) Sinoatrial node B) Atrioventricular node C) Mitral valve D) Bundle of His E) Left ventricle

11) If, during awake brain surgery, a doctor accidentally depolarized a neuron within the somatosensory cortex, which of these is most likely? A) The patient would perceive a specific, localized sensation in one body area. B) The patient would perceive a general sensation all over the body. C) The patient would perceive a general sensation over one side of the body. D) The patient would perceive nothing.

11) Which of the following statements regarding the brain areas that direct emotion is not true? A) The hypothalamus is the site of the conscious feeling of emotion. B) The hypothalamus integrates emotional behaviors. C) The limbic system delivers information about emotion from the cerebral cortex to the hypothalamus. D) The cerebral cortex is responsible for control over emotions. E) None of the choices are true.

12) During a routine brain scan it is discovered that Nick has a larger than average amygdala. How might Nick's family describe Nick? A) Fearful B) Confident C) Jovial D) Always relaxed, easy going E) Hilarious

12) What is the definition of a "motor unit"? A) A single motor neuron plus all the muscle fibers it innervates B) A single muscle fiber plus all of the motor neurons that innervate it C) All of the motor neurons supplying a single muscle D) A pair of antagonistic muscles E) All of the muscles that affect the movement of any given joint

16) Based on its molecular properties, nicotine will have what effect on skeletal muscle contraction? A) Increases in contraction or contraction is more likely to happen B) Decreases in contraction or contraction is less likely to happen C) Effects on the motor neuron, but not on the muscle tissue itself D) Nicotine has no effect on muscle cells

16) Which of the following statements about membrane potentials in different types of cardiac cells is TRUE? A) Myocardial cells have a resting membrane potential of about -90 mV; pacemaker cells do not have a true resting membrane potential. B) Once threshold depolarization is reached in both myocardial and pacemaker cells, the rapid upswing of the action potential is caused by the opening of voltage-gated Na+ channels C) Voltage-gated transient (T-type) Ca2+ channels are present in all of the different types of cells of the heart. D) There are no L-type Ca2+ channels in cardiac muscle cells. E) The upstroke of the action potential is steeper in SA node cells than it is in Purkinje cells.

17) You are dissecting a cadaver. You are tracing an individual neuron as it ascends the spinal cord to the brain. You know that this neuron carries somatic sensory information from an afferent presynaptic neuron. Where will you find its axon terminal? A) All somatic sensory information that reaches the cerebral cortex is first processed in the thalamus. B) Somatic sensory information from the left side of the body projects to the left side of the somatosensory cortex. C) All somatic sensory information travels together in a single tract in the spinal cord. D) Ascending pathways in the anterolateral column of the spinal cord carry information about fine touch discrimination. E) Ascending pathways in the dorsal column of the spinal cord carry information about pain from the back muscles.

18) If an individual was lacking a key amino acid and so couldn't make and release substance P, what would happen? A) They would experience a lack of sensation in some pain pathways. B) There would be a surge in activity in neurons that synthesize opiate neurotransmitters. C) Synaptic activity in afferent neurons associated with pain receptors can be inhibited by axon-axon synapses with neurons from descending pathways. D) There would be an increase in activity in neurons that detect painful stimuli in internal organs. E) There would be increasing sensation of pain generated by the brain, with or without any damage to structures in the periphery.

19) Which is TRUE about the comparison of excitation-contraction coupling in cardiac muscle with that in skeletal muscle? A) Extracellular Ca2+ plays a major role in cardiac but not skeletal muscle. B) The mechanism for Ca2+ release from the sarcoplasmic reticulum is the same in both types of muscle. C) Troponin sites are completely saturated immediately after Ca2+ release in both types of muscle. D) There is no net change in total intracellular Ca2+ concentration in either muscle. E) Intracellular Ca2+ stores are necessary for contraction in skeletal muscle, but not in cardiac muscle.

22) Myasthenia gravis is an autoimmune disease in which the immune system gradually destroys the receptors for acetylcholine at the neuromuscular junction. Which of the following drugs might initially be useful in treating the symptoms of this disease? A) A drug that inhibits acetylcholinesterase B) A drug that inhibits release of acetylcholine C) Curare D) Atropine (a muscarinic acetylcholine receptor antagonist) E) A nicotinic acetylcholine receptor antagonist

23) Of the following substances, which has the greatest potential to cause dependence if used regularly? A) Nicotine B) Marijuana C) Alcohol D) Cocaine E) Heroin

27) Which of these occurs when light strikes photoreceptors? A) The chromophore retinal undergoes a change of shape. B) There is an increase in neurotransmitter release from photoreceptor cells. C) The photoreceptor cell membrane becomes depolarized. D) The concentration of cyclic GMP inside cells increases. E) The photoreceptor cells are stimulated and fire action potentials.

28) The optimal length (Lo) of a skeletal muscle cell is A) the length at which the muscle can generate its maximum tetanic tension. B) the shortest length the muscle can achieve while attached to bone, because the amount of overlap between thick and thin filaments is maximal then. C) generally the length attained when the joint it crosses is fully extended. D) the only length at which any tension can be generated by the muscle cell. E) the length at which thin filaments from opposite sides of a sarcomere overlap.

29) In the first few seconds of skeletal muscle contraction, what is the main mechanism by which ATP is replenished? A) Energy and phosphate are transferred from creatine phosphate to ADP. B) Oxidative phosphorylation rapidly generates ATP from glucose. C) Glycolysis produces ATP from glycogen. D) Oxidation of fatty acids into ATP occurs in the mitochondria. E) Myoglobin catalysis produces ATP.

29) Which of the following is an example of declarative memory? A) Recognition of a person's face and matching a name to it B) Remembering how to ride a bicycle C) Being able to recall a phone number for only a short period of time D) Being given a specific address and being able to recall it several days or weeks later E) Responding to the sight, smell, taste, or thought of one's favorite food with salivation and hunger pangs

31) Vitamin A deficiencies could lead to A) a decrease in rhodopsin and therefore a decrease in night vision. B) a decrease in opsins and therefore a decrease in night vision. C) a decrease in rhodopsin and therefore a decrease in color vision. D) a decrease in opsins and therefore a decrease in color vision. E) None of the above would be affected by a vitamin A deficiency.

31) You have a patient who, following a stroke, has impaired comprehension of language. The MRI is likely to reveal damage in which area? A) Wernicke's area B) Broca's area C) Limbic system D) Hypothalamus E) Damage to any of these areas could cause this symptom

33) Unlike humans, cows eat all day. They spend hours and hours chewing with very little rest from the task in a 24-hour period. The food they eat (grass) is difficult to break down, requiring a lot of chewing. Understanding the endurance required for these chewing muscles, what fiber type would you expect to be predominant in their chewing muscles? A) Type 1 B) Type 2A C) Type 2X D) Type 3 E) There is not enough information to predict a dominant muscle fiber type

35) The most nearly correct sequence of activation of brain areas when one responds in writing to a verbal command is A) primary auditory cortex; Wernicke's area; Broca's area; supplementary motor cortex; primary motor cortex. B) primary auditory cortex; Broca's area; supplementary motor cortex; Wernicke's area; primary motor cortex. C) primary auditory cortex; Broca's area; Wernicke's area; supplementary motor cortex; primary motor cortex. D) primary auditory cortex; Broca's area; Wernicke's area; primary motor cortex; supplementary motor cortex. E) primary auditory cortex; Wernicke's area; Broca's area; primary motor cortex; supplementary motor cortex.

36) An EEG with waves of high amplitude and low frequency is descriptive of or occurs during A) slow-wave sleep. B) paradoxical sleep. C) both slow-wave sleep and paradoxical sleep. D) neither slow-wave sleep nor paradoxical sleep.

34) Which of the following statements regarding higher brain functions is true? A) A person with damage only to Broca's area of the brain will understand spoken or written speech but will have difficulty speaking. B) A person with damage only to Wernicke's area of the brain will have motor aphasia. C) A person with damage only to Wernicke's area of the brain will lose the ability to recognize faces. D) Both "a person with damage only to Broca's area of the brain will understand spoken or written speech but will have difficulty speaking" and "a person with damage only to Wernicke's area of the brain will have motor aphasia" are true. E) Both "a person with damage only to Broca's area of the brain will understand spoken or written speech but will have difficulty speaking" and "a person with damage only to Wernicke's area of the brain will lose the ability to recognize faces" are true.

36) Which of the following statements concerning regulation of blood flow is TRUE? A) In the systemic circuit, increased levels of metabolic waste products and decreased oxygen concentration in tissues promote hyperemia through the tissues. B) If blood flow to a tissue is blocked for a period of time and then the block is removed, the result is a reactive hyperemia in which blood flow through the affected tissue remains low. C) According to flow autoregulation, if blood pressure to an arteriole is decreased, blood flow will not return toward its original level until the original blood pressure is restored. D) In the systemic circuit, high levels of CO2 and metabolites tend to cause contraction in the smooth muscle of arteriole walls. E) The resistance to blood flow in brain and heart vascular beds does not vary in response to changes in local gas or metabolite concentrations.

37) You've been sitting cross-legged on the floor of your dorm room while studying. As you stand up to go get a snack, you realize that you've lost feeling in one of your feet. A minute later, all feeling is restored. Being a physiology student, you understand that blood flow was occluded during the time that you were sitting, and that blood flow was restored as you stood up. What else is TRUE? A) The decreased oxygen content of the foot tissues and the increased levels of metabolic wastes both acted as vasodilators, increasing the flow of blood through the tissues upon standing. B) As you stood, vasoconstriction occurred in the foot's blood vessels to protect them from shock. C) High levels of built up CO2 acted as vasoconstrictors in the foot's blood vessels. D) The resistance of the blood vessels did not change from sitting to standing, but gravity helped in blood flow. E) All of these are true.

38) Which of these would increase the tension generated in a skeletal muscle? A) Increasing the frequency of firing in alpha motor neurons innervating the muscle B) Stretching the muscle to very long lengths C) Resting the muscle for several weeks D) Switching off fast-glycolytic motor units and activating an equal number of slow-oxidative motor units E) Increasing the amplitude of action potentials in the alpha motor neurons that innervate the muscle

39) Which of the following statements regarding whole-muscle contraction is TRUE? A) The order of recruitment of motor units in a muscle is such that the last units recruited are those that fatigue most readily. B) The order of recruitment of motor units in a muscle is such that the first units recruited generate the most tension. C) Motor units whose motor neurons have large-diameter cell bodies are recruited first, while motor units with smaller-diameter motor neurons are only activated as the level of activation in the spinal cord increases. D) The order of motor unit recruitment is independent of the size of the alpha motor neuron that innervates them. E) Recruitment of one fast-glycolytic motor unit provides a smaller increment in whole-muscle tension than recruitment of one slow-oxidative motor unit.

4) A female has a blood test. One mL of her blood is drawn, spun in a centrifuge, and the plasma volume is measured and found to be 0.6 mL. Two months later the same patient returns to the doctor and, after doing another blood test, the doctor tells the patient that she has become anemic compared to her previous visit. Which of the following is most likely to be the woman's hematocrit on the second visit? A) 35% B) 50% C) 70% D) 100% E) 0.6 mL

40) Blood flow through most organs in the systemic circuit is regulated primarily by increasing or decreasing the ________ activity to arteriolar smooth muscles in the organ. Another form of regulation, called ________, depends upon the metabolic activity of the organ. Increased activity leads to increased interstitial fluid metabolites, which cause ________ of the arterioles. The former is a type of ________ regulation of blood flow; the latter is an example of ________ regulation. A) sympathetic; active hyperemia; dilation; extrinsic; intrinsic B) sympathetic; reactive hyperemia; dilation; intrinsic; extrinsic C) parasympathetic; active hyperemia; constriction; extrinsic; intrinsic D) sympathetic; flow autoregulation; constriction; intrinsic; extrinsic E) parasympathetic; reactive hyperemia; dilation; extrinsic; intrinsic

40) Pulsate secretion of growth hormone is descriptive of or occurs during A) slow-wave sleep. B) paradoxical sleep. C) both slow-wave sleep and paradoxical sleep. D) neither slow-wave sleep nor paradoxical sleep.

40) Sarah is a sprinter who specializes in quick and powerful bursts of speed followed by periods of rest. Priya is a marathon runner who specializes in long, steady runs. Compared to Priya, Sarah is likely to have A) leg muscles with a larger diameter. B) leg muscles with a smaller diameter. C) hypertrophy of type I muscle fibers. D) a higher density of capillaries in her leg muscles. E) lower concentrations of glycolytic enzymes in her leg muscles.

41) As the pitch of a sound gets higher, displacements of the basilar membrane A) occur closer to the oval window. B) occur closer to the helicotrema. C) occur uniformly throughout the membrane. D) become greater in amplitude. E) become smaller in amplitude.

43) In a patient with decreased production of plasma proteins, which of the following would be TRUE? A) More fluid than usual will flow out of the capillary based on the osmotic pressure. B) Less fluid than usual will flow out of the capillary based on the osmotic pressure. C) More fluid than usual will flow out of the capillary based on the hydrostatic pressure. D) Less fluid than usual will flow out of the capillary based on the hydrostatic pressure.

44) Which of the following statements concerning the capillaries is FALSE? A) Increasing capillary hydrostatic pressure decreases the likelihood that filtration will occur. B) Velocity of blood flow is slower in the capillaries than in the arteries. C) It is possible for a capillary to filter fluid at its arterial end and absorb fluid at its venous end. D) Large capillary pores are more likely to be found in liver capillaries than in brain capillaries. E) Large proteins that escape capillaries and enter the interstitial fluid are returned to the circulation via the lymphatic system.

44) Which of these is a major difference between smooth muscle and skeletal muscle? A) Myosin is the main regulatory protein in smooth muscle. B) Myosin is the main regulatory protein in skeletal muscle. C) Skeletal muscle usually exhibits spontaneous activity, while smooth muscle cannot contract spontaneously. D) Only skeletal muscle requires increased calcium ion concentration in the cytosol for contraction. E) Only skeletal muscle has both actin and myosin.

46) A patient comes in to your office with dramatically high blood pressure. Which of the following symptoms might turn up in your exam? A) Tissue swelling due to increased fluid leaving the capillaries B) Skin bruising due to blood leaving the capillaries C) Rapid breathing due to increased need for oxygen D) Lethargy E) None of these

48) Which of the following is FALSE regarding single-unit smooth muscle cells? A) They have an individual neuron innervating each individual smooth-muscle cell. B) They have many gap junctions between cells. C) They may have pacemaker activity. D) They may respond to stretch by contracting. E) They exhibit tone.

49) Which of the following properties of smooth muscle helps us to understand why, as pregnancy advances, women get more and more Braxton-Hicks (smooth muscle) contractions in the uterine wall? A) Smooth muscle cells contract in response to stretch. B) Smooth muscle cells contract in response to NO. C) Smooth muscle cells contract in response to CO2. D) Smooth muscle cells contract in response to changes in pH.

5) During paradoxical sleep A) brain neurotransmitter activity in the pathways regulating states of consciousness is similar to that in the awake state. B) brain oxygen consumption is lower than when awake. C) skeletal muscle tension is dramatically increased. D) the person is easily aroused. E) All of the choices are correct.

50) Multiunit smooth muscle cells A) generally have individual innervation of each cell. B) have many gap junctions between cells. C) respond to stretch by relaxing. D) can only be excited, and not inhibited. E) have abundant T-tubules.

50) What category of receptors do Pacinian corpuscles belong to? A) Mechanoreceptors B) Chemoreceptors C) Nociceptors D) Photoreceptors

51) Tina is a hard-working sales clerk in a busy department store. She has stood completely still behind the check-out counter for an 8-hour shift. At the end of Tina's shift she finds that she feels somewhat dizzy and guesses that her blood pressure is quite low. All of the following factors normally contribute to homeostatic blood pressure regulation. Which one is most likely contributing to her symptoms? A) Decreased skeletal muscle pump B) Increased activity of the pulmonary pump C) Defective baroreceptor detection in the carotid artery D) Increased sympathetic tone E) All of these

51) What category do hair cells in the organ of Corti belong to? A) Mechanoreceptors B) Chemoreceptors C) Nociceptors D) Photoreceptors E) Proprioceptors

54) Hair cells in semicircular canals are A) mechanoreceptors. B) chemoreceptors. C) nociceptors. D) photoreceptors. E) audioreceptors.

59) Jane donates a pint of blood to a blood bank. A few minutes later, which of the following would be increased compared to pre-donation values? A) Heart rate B) Stroke volume C) Mean arterial pressure D) Cardiac output E) Hydrostatic pressure in the capillaries

64) You just ate a huge, delicious breakfast and now are going to head out for your morning run. As you try picking up the pace, you find running to be quite difficult because A) blood flow to the abdominal organs is dominant. B) stroke volume is decreased. C) everywhere in the systemic circuit, blood vessels are constricted. D) your heart rate is too high. E) your mean arterial pressure is too high.

67) Which of these correctly states differences between a trained athlete and a sedentary individual at rest? A) The athlete would have a lower heart rate and larger stroke volume. B) The athlete would have a higher heart rate and larger stroke volume. C) The athlete would have a lower heart rate and smaller stroke volume. D) The athlete would have a higher heart rate and smaller stroke volume. E) There would be no differences when the individuals were at rest.

72) Atherosclerosis is A) the major cause of heart attacks. B) a thinning in the walls of arteries. C) associated with low blood levels of cholesterol and heavy exercise. D) a disease in which the walls of arteries become more compliant. E) more common in younger people than in older people.

77) In a patient with a mutation that causes an inactive von Willebrand factor (vWF), which of the following would be TRUE? A) Platelets will not adhere to collagen. B) Fibrinogen cannot polymerize. C) Thrombin will never be activated. D) Clots will be stronger than typical. E) None of the answers will be true.

78) Which of the following statements regarding blood clotting is TRUE? A) Blood clotting requires activation of thrombin. B) Blood clotting is enhanced by prostaglandin I2 (PGI2) and nitric oxide. C) A blood clot is a network of interlacing strands of fibrinogen. D) Blood clotting occurs too rapidly in individuals with the disease hemophilia. E) Injecting tissue plasminogen activator (t-PA) into a patient who is bleeding will aid blood clotting.

8) What would be the result if the administration of a drug sequesters all the ATP in a cell? A) All cross-bridges will remain tightly bound to actin. B) Calcium will remain in the cytosol, continuously stimulating cross-bridge cycling. C) Repeated, high-frequency action potentials will be fired at a skeletal muscle fiber causing sustained contraction. D) Calcium-activated proteases degrade all proteins in skeletal muscle fibers, making muscles limp. E) A build-up of K+ in T-tubules will cause constant, tetanic contractions of skeletal muscles.

81) Which of the following is NOT an anticoagulant or stimulator of blood clot dissolution? A) Vitamin K B) Aspirin C) Thrombin D) Heparin E) Tissue plasminogen activator (t-PA)

9) When you eat a spicy pepper, such as a jalepeño, why do you perceive heat in your mouth? A) A chemical within the jalepeño acts as a stimulus for thermoreceptors. B) The breakdown of chemicals within the pepper causes exothermic reactions in the mouth. C) Friction while chewing activates thermoreceptors. D) Chemoreceptors can activate heat sensing parts of the brain. E) All of the answer choices are correct.

9) Which of the following changes would most increase the resistance to blood flow in a blood vessel? A) Halving the diameter of the vessel B) Doubling the diameter of the vessel C) Halving the length of the vessel D) Doubling the length of the vessel E) Decreasing the hematocrit from 50% to 40%

Constriction of the ________ decreases hydrostatic pressure in ________. A) afferent arterioles; glomerular capillaries B) efferent arterioles; proximal convoluted tubules C) renal vein; peritubular capillaries D) efferent arterioles; glomerular capillaries E) efferent arterioles; Bowman's capsule

Drug X is a new drug to treat Alzheimer's Disease. This drug is able to cross the blood-brain barrier and circulate in the CSF. The drug is slightly acidic and at the recommended dose it decreases the CSF pH from 7.4 to 7.3. Will Drug X have any effect on respiration? A) It will cause an increase in respiratory rate. B) It will cause a decrease in respiratory rate. C) It will have no effect on respiratory rate, but will cause an increase in depth of breathing. D) It will have no effect on respiratory rate, but will cause the patient to take shallower breaths. E) It will not impact respiratory function.

Following a few months of noticeably high urine volume, Stephanie's doctor diagnosed her with diabetes insipidus and prescribed her desmopressin, which is a synthetic drug form of vasopressin. A few weeks later, Stephanie accidentally takes two doses instead of one. On that day, what is Stephanie likely to experience? A) An increase in the osmolarity of urine B) An increased urine volume C) A decrease in blood pressure D) A noticeable reduction in thirst and desire to drink water E) None of these would occur

How would the kidneys respond to hypoventilation? A) Increasing secretion of H+ and increasing production of new HCO3- B) Increasing secretion of H+ and decreasing reabsorption of HCO3- C) Decreasing secretion of H+ and increasing production of new HCO3- D) Decreasing secretion of H+ and decreasing reabsorption of HCO3- E) Increasing excretion of CO2

If a patient with pulmonary disease began to hypoventilate, how would plasma levels of [H+], HCO3-, and PCO2 be changed, compared to normal? A) Increased [H+], increased PCO2, and increased [HCO3-] B) Increased [H+], increased PCO2, and decreased [HCO3-] C) Increased [H+], decreased PCO2, and decreased [HCO3-] D) Decreased [H+], increased PCO2, and decreased [HCO3-] E) Decreased [H+], decreased PCO2, and decreased [HCO3-]

If the nerves from the carotid and aortic bodies are cut, which of these would occur? A) A decrease in arterial PO2 will no longer increase ventilation. B) An increase in arterial PCO2 will no longer increase ventilation. C) An increase in arterial lactic acid will inhibit ventilation. D) An increase in arterial PCO2 will inhibit ventilation. E) A decrease in arterial PO2 will inhibit ventilation.

In a hypothetical rare genetic disease in which the ribosomes in some cells of the anterior pituitary are malformed. Which hormone, if any, would you expect missing from a patient with this disease? A) Anti-diuretic hormone B) Thyroid hormone C) Progesterone D) Estrogen E) Oxytocin

In the presence of aldosterone, which nephron region reabsorbs the greatest fraction of the filtered Na+? A) Proximal tubule B) Macula densa C) Descending limb of the loop of Henle D) Distal convoluted tubule E) Cortical collecting duct

In what segment of the nephron is the greatest fraction of filtered water reabsorbed? A) The proximal tubule B) The ascending limb of the loop of Henle C) The distal convoluted tubule D) The collecting ducts E) The descending limb of the loop of Henle

In which form is most of the oxygen carried in arterial blood? A) Bound to hemoglobin B) Dissolved in the plasma C) Dissolved in the cytosol of erythrocytes D) Converted to HCO3- E) Bound to myoglobin

It's final exam time and you're finding yourself extremely stressed out. If we examined your blood, which of the following would we be likely to find? A) Increased secretion of corticotropin from the anterior pituitary B) Increased secretion of corticotropin from the hypothalamus C) Increased secretion of adrenocorticotropic hormone (ACTH) from the hypothalamus D) Negative feedback to the adrenal cortex by adrenocorticotropic hormone (ACTH) E) Decreased secretion of corticotropin-releasing hormone (CRH) by the hypothalamus

Most of the reabsorption of filtered calcium is unregulated and occurs in the ________, but an additional amount can be reabsorbed in the ________, depending on the plasma concentration of parathyroid hormone. A) proximal convoluted tubule; distal convoluted tubule B) distal convoluted tubule; proximal convoluted tubule C) proximal convoluted tubule; descending loop of Henle D) distal convoluted tubule; medullary collecting ducts E) distal convoluted tubule; renal corpuscle

Sally is a 10-year-old girl going through a growth spurt. Her blood levels of growth hormone are two-fold higher than at the same time last week. Which other hormones are likely to also be elevated? A) Insulin-like growth factor 1 B) Prolactin C) Cortisol D) ACTH E) Follicle-stimulating hormone

Which is TRUE regarding the structure and synthesis of hormones? A) Steroid hormones are synthesized from cholesterol. B) Thyroid hormones are catecholamines. C) The hormones of the adrenal cortex have the same structure as the neurotransmitters of adrenergic neurons. D) Most peptide hormones require binding proteins for transport in the blood. E) Vasopressin is synthesized in the posterior pituitary.

Which is most likely a result of hypersecretion of growth hormone? A) Acromegaly B) Dwarfism C) Decreased plasma concentration of IGF-I D) Decreased secretion of somatostatin E) Increased secretion of growth hormone-releasing hormone (GHRH)

Which is normally TRUE about the intrapleural pressure? A) It is lower than alveolar pressure. B) It is between +5 and +10 mmHg above atmospheric pressure at functional residual capacity. C) It alternates between being less than, and greater than, atmospheric pressure. D) During a passive exhale, it increases to a value above atmospheric pressure. E) It is always the same as atmospheric pressure during a passive exhale.

Which of the following conditions would result in a systemic arterial PO2 lower than is typical of a healthy person at sea level? A) Traveling to high altitude B) Breathing 100% oxygen C) Having iron-deficiency anemia D) Breathing regular air in a hyperbaric chamber (higher that normal atmospheric pressure) E) Maintaining alveolar ventilation constant while decreasing metabolic rate

Which of the following is NOT a function of the respiratory system? A) Net uptake of carbon dioxide from the air and removal of oxygen from the blood B) Regulation of blood H+ concentration C) Trapping of blood clots D) Phonation E) Defense against microbes

Which of the following is NOT true regarding ventilation-perfusion inequality? A) No inequality exists in normal lungs. B) It may result from increased alveolar dead space. C) It is increased from normal in patients with emphysema. D) It is caused by too little or too much blood flow relative to ventilation. E) It is caused by too little or too much ventilation relative to blood flow.

Which of the following is TRUE about how water is handled by the nephron? A) Water is filtered out of glomerular capillaries by bulk flow. B) Water is actively reabsorbed from the proximal tubule, and Na+ follows down its diffusion gradient. C) Water is actively secreted into the descending loop of Henle. D) The permeability of the ascending limb of the loop of Henle is modified by vasopressin. E) Vasopressin inserts pumps in the collecting duct membrane that move water against its concentration gradient.

Which of the following is an action of the sympathetic nervous system during stress? A) It increases the ability to respond to situations where physical activity is required. B) It increases blood flow to the skeletal muscles and viscera. C) It inhibits blood clotting. D) It decreases ventilation of the lungs to save oxygen. E) It increases glycogen synthesis in the liver.

Which of the following statements about renal control of blood acid-base balance is TRUE? A) Increased metabolism of glutamine by renal tubular cells increases the plasma bicarbonate concentration. B) Excretion in the urine of hydrogen bound to phosphate buffers decreases plasma bicarbonate concentration. C) H+ that binds to filtered bicarbonate in the tubular fluid is excreted in the urine. D) When hypoventilation occurs at the lungs, the kidneys compensate by reducing glutamine metabolism. E) The kidneys compensate for a metabolic alkalosis by increasing CO2 production.

Which of the following statements concerning the process of glomerular filtration is correct? A) The hydrostatic pressure in Bowman's space opposes filtration. B) The glomerular filtration rate is limited by a transport maximum. C) All of the plasma that enters the glomerular capillaries is filtered. D) The osmotic force due to plasma proteins favors filtration. E) The hydrostatic pressure in glomerular capillaries opposes filtration.

Which of the following statements regarding Ca2+ homeostasis is TRUE? A) Parathyroid hormone directly stimulates Ca2+ reabsorption by the kidneys. B) Parathyroid hormone directly stimulates Ca2+ absorption from the GI tract. C) In the absence of parathyroid hormone, plasma Ca2+ levels would be abnormally low, resulting in the hyperpolarization of nerve and muscle membranes. D) When plasma Ca2+ increases above normal, the secretion of parathyroid hormone increases. E) Vitamin D decreases the renal tubular reabsorption of Ca2+.

Which of the following statements regarding hypoxia is correct? A) Exposure to high altitude is a form of hypoxic hypoxia. B) "Anemic hypoxia" refers to the condition of lower than normal arterial PO2. C) Carbon monoxide poisoning is an example of hypoxic hypoxia. D) Carbon monoxide poisoning is an example of ischemic hypoxia. E) Cyanide poisoning is an example of hypoxic hypoxia.

Which of these describes secondary hypersecretion of hormone X? A) A growing tumor secretes hormone Y, which stimulates the gland that secretes hormone X. B) Cells of a growing tumor manufacture hormone X in unregulated fashion. C) Negative feedback from a tumor that hypersecretes hormone Z inhibits the gland that secretes hormone X. D) Hormone X is secreted by a growing tumor that is in the anterior pituitary gland. E) Hormone X is secreted in unregulated fashion by a tumor growing in a tissue that does not normally secrete hormone X.

Which stimulates vasopressin secretion? A) Increased plasma osmolarity B) Increased plasma volume C) Ingestion of alcohol D) Decreased aldosterone secretion E) Increased pressure in afferent arterioles

Which would be the effect of a blood clot that blocked the vessels of the hypothalamo-pituitary portal system in the infundibulum between the hypothalamus and the anterior pituitary gland? A) Secretion of adrenocorticotropic hormone (ACTH) would decrease and the adrenal cortex would atrophy B) Secretion of gonadotropins will decrease and the gonads will hypertrophy C) Secretion of corticotropin-releasing hormone (CRH) would decrease D) Secretion of prolactin would decrease E) Secretion of follicle-stimulating hormone (FSH) would increase

Yolanda was born with a rare genetic disease in which the proximal tubules of her nephrons express half the number of aquaporins as is typical. What will be the result? A) Reduced reabsorption of water, although as much reabsorption of Na+ as is typical B) Reduced reabsorption of both water and Na+ in equal proportions C) Reduced reabsorption of all materials in the proximal tubules D) Reduced reabsorption of water, Na+, and glucose in the proximal tubules E) No change to reabsorption at this site

You are a scientist for the Federal Drug Administration (FDA). An agricultural company wants to market a new pesticide they have developed for use on produce in the United States. This pesticide is hydrophilic, has a small molecular weight (it is slightly smaller than glucose), and it does not bind to any proteins. Which of the following is an appropriate hypothesis for how this drug will be found in the body? A) The pesticide will mostly be cleared in the feces as it will bind to cholesterol, which is added to the GI tract. B) The pesticide will remain in the blood for a long period as it is not filtered or secreted by the urinary tract. C) The pesticide will mostly be cleared in the urine as it will be filtered but not reabsorbed. D) The pesticide will be cleared through the skin as it will diffuse through the skin layers and evaporate from the surface.

You walk into your dorm room and find your roommate in the midst of anxiety-induced hyperventilation. You're unable to calm her down, so you call an ambulance. When she arrives at the ER, which of the following is her likely diagnosis? A) Respiratory alkalosis B) Respiratory acidosis C) Increased blood PCO2 D) Metabolic acidosis E) Metabolic alkalosis

1) It is believed that the rhythmic patterns of the EEG most likely originate from this structure in the brain. A) Hypothalamus B) Cerebral cortex C) Basal ganglia D) Cerebellum E) Hippocampus

1) Which best describes a "myofibril"? A) It is a single skeletal muscle cell. B) It is a cylindrical cellular organelle composed of myofilaments. C) It is a hollow membranous structure that stores calcium. D) It is composed of a single type of protein and forms cross-bridges. E) It is a fibrous junction between a muscle cell and a tendon.

10) A laboratory rat has an electrode implanted in its brain. By pressing a metal bar in its cage, the animal can activate the electrode. You are analyzing the data from the most recent experiment day and find that the rat pressed the bar over and over again. The rat did not even eat during the experimental period because it was too busy pressing the bar. In which location is the electrode likely to be implanted? A) Frontal lobe B) Mesolimbic system C) Hypothalamus D) Occipital lobe E) All of the choices are possible locations of the electrode.

10) Action potentials in the heart spread from cell to cell through A) desmosomes. B) gap junctions. C) interneurons. D) valves. E) coronary vessels.

13) You are a veterinarian and a dog is brought in that has experienced a BB gun shot to the brain. The brain scan reveals damage to the septum of the limbic system. You need to explain this injury to the owners. Which of the following is true? A) The septum is required for the expression of rage, with a damaged septum, this dog will always be docile and never aggressive. B) In a normal animal, the septum inhibits the amygdala. Without it, the dog will always be fearful and vicious. C) The septum of the limbic system is required for memory formation. The dog will be forever forgetful D) The septum of the limbic system is required for regulation of appetite. Without it, the dog may overeat. E) The septum of the limbic system is required to express affection, without it, the dog may be less affectionate.

14) Which best describes lateral inhibition in the somatic sensory system? A) The frequency of action potentials along pathways from the site of a stimulus is increased by lateral inhibition. B) The precision of locating a stimulus is increased by inhibiting signaling along nearby, parallel pathways. C) The precision of locating a stimulus is enhanced by increasing the frequency of action potentials in nearby, parallel pathways. D) Stimuli of one particular modality in a region of the body block transmission of action potentials coding for other modalities generated in the same region of the body. E) Lateral inhibition reduces the contrast between the frequency of action potentials generated at the center of a stimulus and the frequency of action potentials in surrounding pathways.

14) You are a veterinarian and a dog is brought in that has experienced a BB gun shot to the brain. The brain scan reveals damage to the amygdala. You need to explain this injury to the owners. Which of the following is true? A) The amygdala is required for the expression of affection. B) In a normal animal, the amygdala is involved in expression of fear and rage. Without it, the dog may be docile at all times. C) The amygdala is required for memory formation. The dog will be forever forgetful. D) The amygdala is required for regulation of appetite. Without it, the dog may overeat. E) The amygdala is required to express affection, without it, the dog may be less affectionate.

19) Drugs that are used to treat depression increase the levels of this neurotransmitter in the brain. A) Glutamate B) Serotonin C) GABA D) Acetylcholine E) Dopamine

2) What protein is the principal component of skeletal muscle thick filaments? A) Actin B) Myosin C) Troponin D) Calmodulin E) Tropomyosin

20) Accommodation for near vision requires A) flattening of the lens. B) contraction of the ciliary muscles. C) activation of the sympathetic nervous system. D) increased rounding of the cornea. E) dilation of the pupil.

20) You and your lab partner are doing an experiment in physiology lab. Each of you has an isolated muscle cell and you are supposed to stimulate it with an electrode as soon as its absolute refractory period ends. You're watching an electromyograph tracing to know when to use the electrode. Your partner has a cardiac muscle cell and you have a skeletal muscle cell. Which one of you will use your electrode more times in one minute? A) Your partner will use the electrode more times in a minute than you will. B) You will use the electrode more times in a minute than your partner will. C) You both will use the electrode the same number of times. D) The number of times you will use the electrode in a minute cannot be determined by this information alone.

21) Tetanus toxin inhibits acetylcholinesterase activity. What will a person suffering from tetanus toxin poisoning look like? A) All muscles of the body might exhibit frequent small twitches. B) All muscles of the body might present a tense, fully contracted state. C) All muscles of the body might present a limp, relaxed state known as flaccid paralysis. D) All muscles of the body will be completely normal in function.

25) In a patient with an abnormally leaky aortic valve, what would you expect? A) Some backflow of blood into the aorta during ventricular diastole B) Some backflow of blood into the left ventricle during ventricular diastole C) Some backflow of blood into the left ventricle during ventricular ejection D) Some backflow of blood into the aorta during ventricular ejection E) Some backflow of blood into the left atrium during ventricular systole

26) What is the best description of a tetanic contraction in a skeletal muscle cell? A) A single action potential in the motor neuron causes a sustained contraction. B) Multiple action potentials in the motor neuron cause a sustained contraction. C) The action potential in the muscle cell is prolonged to last as long as the contraction. D) Repeated action potentials from the motor neuron summate into a sustained depolarization of the motor end plate, causing a sustained contraction. E) A very large amplitude action potential in the motor neuron causes a very strong contraction in the skeletal muscle cell.

26) Which occurs during isovolumetric ventricular contraction? A) Rapid filling of the ventricles occurs. B) No blood enters or leaves the ventricles. C) The maximum volume of blood is ejected. D) Ventricular pressure reaches its maximum value of the cardiac cycle. E) The pressure in the ventricles decreases while the pressure in the atria increases.

27) What causes the opening and closing of the heart valves? A) Stimulation by the sympathetic and parasympathetic nerves B) A pressure difference on the two sides of the valve C) Na+ and K+ fluxes during ventricular depolarization D) Turbulent flow in the atria and ventricles E) The action of the papillary muscles and chordae tendineae

28) You have a new patient who describes having a lot of difficulty in being able to remember meeting new people. An MRI reveals damage to which structure? A) Thalamus B) Hippocampus C) Hypothalamus D) Corpus callosum E) Broca's area

28) You've just been told by your doctor that you have a heart murmur between the first and second heart sounds. You go home to search for more information on this condition on the Internet and find that you have A) insufficiency of a semilunar valve or stenosis of an AV valve. B) insufficiency of an AV valve or stenosis of a semilunar valve. C) heart failure. D) AV nodal conduction block. E) a myocardial infarction.

3) If you were to record your own EEG activity while concentrating very hard on this exam, the most prominent EEG pattern would be A) alpha rhythm. B) beta rhythm. C) delta rhythm. D) theta rhythm.

31) Which of the following statements regarding myosin in skeletal muscle is TRUE? A) Myosin cross-bridge heads contain two binding sites, one for actin and one for tropomyosin. B) Myosin is an ATPase. C) The rate of ATP hydrolysis by myosin is the same in all types of skeletal muscle. D) All of the myosin cross-bridge heads in a thick filament are oriented and rotate in the same direction. E) Troponin covers the binding site on myosin molecules until Ca2+ binds to troponin to remove it from its blocking position.

32) Compared to type 1 (slow oxidative) skeletal muscle fibers, how are type 2X (fast-glycolytic) skeletal muscle fibers different? A) Type 2X fibers have more abundant mitochondria. B) Type 2X fibers fatigue more readily. C) Type 2X fibers have more abundant myoglobin. D) Type 2X fibers are smaller in diameter. E) Type 2X motor units contain fewer fibers per alpha motor neuron.

32) Which of these is most responsible for "light adaptation"—the process by which we only gradually become able to see objects in a brightly lit place after being in the dark? A) Cone receptors are very hyperpolarized in the dark, and they must be exposed to bright light for awhile before they will depolarize. B) Rhodopsin is quickly inactivated in the presence of bright light so rods become unresponsive, and the higher-acuity cones then become the main detectors of vision. C) Because rods are more sensitive to light than cones, they gradually become extremely activated in bright light. D) Cones and rods are stimulated equally, leading to difficulties in interpreting the sensory inputs to the brain. E) Rhodopsin is not activated by colored light, and the lack of stimulation causes rods to gradually depolarize when we are exposed to bright light.

35) Which of the following statements related to the "ON pathway" of the visual system is correct? A) Bipolar cells fire action potentials only when bright light strikes the photoreceptors linked to them. B) Bipolar cells spontaneously depolarize in the absence of input from photoreceptor cells. C) Bipolar cells hyperpolarize in the absence of input from photoreceptor cells. D) Glutamate receptors on bipolar cells are excitatory. E) Only cones are associated with bipolar cells of the "ON pathway," rods are not.

37) Rapid eye movement is descriptive of or occurs during A) slow-wave sleep. B) paradoxical sleep. C) both slow-wave sleep and paradoxical sleep. D) neither slow-wave sleep nor paradoxical sleep.

38) In the systemic circuit, which of these best describes active hyperemia? A) Increased metabolic activity that results in vasoconstriction B) Increased metabolic activity that results in vasodilation C) Decreased blood flow to tissues that results in vasoconstriction D) Decreased blood flow to tissues that results in vasodilation E) Increased blood pressure that drives blood more rapidly through tissues

39) Absence of postural muscle tone is descriptive of or occurs during A) slow-wave sleep. B) paradoxical sleep. C) both slow-wave sleep and paradoxical sleep. D) neither slow-wave sleep nor paradoxical sleep.

39) The receptors for hearing are found on the A) tympanic membrane. B) basilar membrane. C) stapes. D) oval window. E) scala vestibuli.

4) Your alarm pulls you from sleep while you were in the middle of a vivid dream. You were most likely A) in NREM sleep. B) in REM sleep. C) exhibiting beta wave activity. D) exhibiting gamma wave activity. E) All of the answer choices are correct.

40) Distinguishing the pitch of sounds is possible because A) different frequencies of sounds make the eardrum vibrate with different amplitudes. B) different frequencies of sounds stimulate different regions of the basilar membrane in the cochlear duct. C) different frequencies of sounds cause different kinds of action potentials in neurons in the auditory nerve. D) different frequencies of sounds cause different frequencies of action potentials in neurons in the auditory nerve. E) there are many different types of receptors for sound, each of which responds to a single frequency.

41) Dreaming is descriptive of or occurs during A) slow-wave sleep. B) paradoxical sleep. C) both slow-wave sleep and paradoxical sleep. D) neither slow-wave sleep nor paradoxical sleep.

41) Sarah is a sprinter who specializes in quick and powerful bursts of speed followed by periods of rest. Priya is a marathon runner who specializes in long, steady runs. Compared to Sarah's muscles, how are Priya's most likely to differ? A) Priya muscles will have more glycogen stored in her type 2X muscle fibers. B) Priya's muscles will have more mitochondria in her type 1 and 2A muscle fibers. C) Priya's muscles will have less myoglobin in her type 1 muscle fibers. D) Priya's type 2X fibers will be larger in diameter. E) Priya will have a greater proportion of type 2 muscle fibers and a lower proportion of type 1 fibers than Sarah.

42) Which of the following is NOT a function of the tensor tympani and stapedius muscles? A) Protection of the inner ear against continuous loud sounds B) Protection of the delicate inner ear from sudden intermittent loud sounds C) Reflexive contraction when vocalizing to reduce the loudness of your own voice D) Optimization of the state of the inner ear for hearing over certain frequency ranges

46) Due to anatomical pathways that involve the limbic system, which type of sensation can lead to the most immediate emotional reactions? A) Taste B) Smell C) Touch D) Hearing E) Equilibrium

47) Which is TRUE about information from the vestibular system? A) It is conveyed in the form of action potentials in the optic nerve. B) It is conveyed to nerves that control eye movements. C) It does not reach the level of conscious perception. D) It is primarily conveyed to the cortex of the occipital lobe of the brain. E) It is interpreted as sound in the temporal lobes of the brain.

47) You have a patient who is showing signs of edema (tissue swelling) all over his body. In addition to visible swelling in his hands, feet, and face, you can also see evidence of swelling around his organs when viewing his CAT scan images. Thinking about what you know about the factors that regulate fluid flow from the blood vessels. Which of the following causes of edema seem most likely? A) Low red and white blood cell counts due to cancer in the bone marrow B) Low plasma protein concentration due to liver failure C) High blood solute concentration due to kidney failure D) Low blood pressure due to severe dehydration

48) Distinguishing characteristics of veins include which of the following? A) All veins carry deoxygenated blood. B) All veins carry blood toward the heart. C) All veins have thick, elastic walls. D) Veins have walls consisting only of endothelial cells. E) All veins have valves to ensure one-way movement of blood.

49) The phenomenon known as referred pain: A) is a perception of a false painful stimulus with no initiating stimulus, it is created in the mind. B) is the projected perception of pain as a sensation being experienced at a site other than that of the actual injured or diseased tissue. C) involves a descending pathway that blocks the release of substance P in the spinal cord. D) is synonymous with the persistence of perceptions of painful stimuli long after the activity responsible for triggering them has ceased.

50) Sarah is resting in a chair for a long period of time; her calf and thigh muscles are totally relaxed. Next to her, Priya is also resting in a chair, but she is wiggling, kicking, tapping, and vibrating her legs; resulting in an pattern where her calf and thigh muscles are alternating between relaxed and contracted states. If all else is equal, who has the higher stroke volume, Sarah or Priya? A) Sarah has a higher stroke volume. B) Priya has a higher stroke volume. C) Sarah and Priya have the same stroke volume because they are both seated. D) No significant difference in the stroke volume between Sarah and Priya can be predicted based on this information.

53) In what category of sensory receptors are the receptor cells in taste buds? A) Mechanoreceptors B) Chemoreceptors C) Nociceptors D) Photoreceptors E) Proprioceptors

53) The prolonged electrical depolarization of cardiac muscle cells that occurs during contraction is due primarily to the persistent influx of what ion? A) Sodium B) Calcium C) Nitrate D) Chloride E) Potassium

54) Sally has had too many alcoholic drinks. Alcohol is a systemic vasodilator and it increases urine volume, thereby decreasing blood volume. In order to maintain cardiac output, what can her body do? A) Decrease heart rate B) Increase heart rate C) Increase stroke volume D) Decrease stroke volume E) Increase total peripheral resistance (TPR)

56) After a long fever Carl finds himself sweating profusely. He ends up requiring several changes of clothing before his skin begins to dry off. After this sweating event, what can we expect of Carl's physiological state? A) An increase in blood volume B) Hypotension C) Decreased firing of the arterial baroreceptors D) Increased stroke volume E) All of these

57) Jane donates a pint of blood to a blood bank. A few minutes later, which of the following would be increased compared to pre-donation values? A) Her stroke volume and total peripheral resistance B) Her heart rate and total peripheral resistance C) Her heart rate and mean arterial pressure D) The percentage of her cardiac output flowing to her kidneys E) The blood flow to her brain

57) Myasthenia gravis is a collection of muscle disorders that cause muscle fatigue and weakness. What is the major mechanism? A) Overproduction of acetylcholinesterase B) Autoimmune destruction of nicotinic acetylcholine receptors C) Demyelination of axons in motor pathways D) Autoimmune destruction of L-type Ca2+ channels. E) A tumor that overproduces acetylcholine

6) Binding of ________ to myosin permits cross-bridge ________ between actin and myosin in skeletal muscle cells. A) ATP; attachment B) ATP; detachment C) calcium; attachment D) calcium; detachment E) actin; detachment

66) Which is the most likely effect of physical endurance training on a person's cardiac performance? A) A decrease in cardiac output B) An increase in maximal stroke volume C) An increase in maximal heart rate D) An increase in resting heart rate E) An increase in cardiac output when the person is at rest

7) Polymodal neurons are A) afferent neurons. B) interneurons that receive synaptic input from different kinds of sensory units. C) part of specific ascending sensory pathways. D) interneurons that receive synaptic input from only one type of sensory unit. E) efferent neurons.

7) Which occurs FIRST as a result of ATP binding to myosin? A) Cross-bridge heads are cocked into an "energized" state. B) Actin dissociates from myosin. C) Ca2+ is released from the sarcoplasmic reticulum. D) Actin binds to myosin. E) Cross-bridges rotate, sliding past the thin filament.

7) You have a patient who has pernicious anemia. Which of the following supplements should she take to improve her symptoms? A) Iron B) Vitamin B12 C) Vitamin E D) Vitamin D E) Bilirubin

70) Which of the following drugs might be prescribed to alleviate hypertension? A) Alpha-adrenergic receptor agonists B) Beta-adrenergic receptor antagonists C) Cholinergic antagonist D) A drug that increases L-type Ca2+ channel currents E) A drug that increases T-type Ca2+ channel currents

73) What is hemostasis? A) The maintenance of relatively stable conditions in the internal environment B) The prevention or stoppage of blood loss C) A disease in which blood clot formation is impaired D) A protein inside red blood cells that binds oxygen with high affinity E) The set point for normal arterial blood pressure

74) Which of the following occurs first in hemostasis? A) Activation of the fibrinolytic system B) Platelet aggregation C) A clotting cascade that leads to the conversion of fibrinogen to stable fibrin D) Conversion of prothrombin to thrombin E) Conversion of plasminogen to plasmin

8) Consider the equation F = ΔP/R. It describes the flow (F) of fluid in a tube in which there is a pressure difference (ΔP) between the two ends and a resistance (R) to flow. Based on this equation, which is a correct conclusion? A) The flow of fluid in a tube depends upon the absolute pressure at the beginning of the tube. B) The rate of fluid flow in a tube will increase if the pressure at the beginning is increased while the pressure at the end of the tube stays the same. C) The greater the resistance to flow in a tube, the greater the rate of flow for any given pressure difference. D) If both the resistance and the pressure gradient in a tube increase, the flow must also increase. E) The rate of flow in a tube will decrease if the resistance to flow is decreased.

8) Which is an accurate description of the cortical association areas? A) They are all found in the parietal lobe of the cerebral cortex. B) They integrate multiple types of sensory information and are responsible for complex processing of sensory information. C) They are the cortical locations where primary sensory information first arrives from specific ascending pathways. D) They are found deep in the cerebrum, surrounding the thalamus. E) Their main input is sensory information arriving along neurons that project directly from the thalamus.

9) You have a patient who, after undergoing treatment for a brain disease, has a high amount of protein fragments and waste products in his CSF. To aid in clearance, which might you recommend? A) A drug that increases heart rate B) Sleep C) Hanging upside down D) Ingestion of acidic foods E) None of the answer choices are correct.

A decrease in metabolism without a similar, compensatory decrease in alveolar ventilation will have what effect on the systemic pH? A) pH will decrease. B) pH will increase. C) No change to pH is expected in this circumstance. D) It is impossible to predict the effect on pH without first understanding why metabolism decreased.

Andres has a parathyroid hormone deficiency. He first approached the doctor because he was experiencing ________ and the early blood tests found that he had ________. A) decreased muscular excitability; low plasma calcium levels B) increased muscular excitability; low plasma calcium levels C) decreased muscular excitability; high plasma calcium levels D) increased muscular excitability; high plasma calcium levels E) frequent bones breaks; high plasma calcium levels

Carbonic anhydrase catalyzes a reaction that combines which of the following? A) H2O and O2 B) H2O and CO2 C) H2O and CO D) H+ and HCO3- E) CO2 and O2

During a long illness, Terrell has not been eating much. As a result, his plasma Ca2+ levels decrease. Which hormone would we expect to see in higher levels than usual in his blood? A) Thyroxine B) Parathyroid hormone C) Calcitonin D) Growth hormone E) Insulin

During a physical examination, Joe learns that his resting tidal volume is 550 mL; his average resting respiratory rate is 15 breaths per minute; his total lung capacity is 6,000 mL; and his anatomic dead space is 150 mL. Joe's resting alveolar ventilation is A) 72.0 L/min. B) 6.0 L/min. C) 4.2 L/min. D) 1.8 L/min. E) 0.5 L/min.

During a run, your gastrocnemius (calf) muscle has a temperature of 38.5° C, while your biceps brachii (upper arm) muscle has a temperature of 37.5° C. Which of the following is TRUE of the red blood cells as they pass by these muscles? A) The hemoglobin molecules will have the same affinity for oxygen at both locations. B) The hemoglobin molecules will have a higher affinity for oxygen as they pass by the biceps brachii compared to the gastrocnemius. C) The hemoglobin molecules will have a higher affinity for oxygen as they pass by the gastrocnemius compared to the biceps brachii. D) The hemoglobin molecules may denature as they pass by the gastrocnemius.

During a yoga class you take a deep breath, then relax and let the breath out slowly. During that exhalation, which would NOT be true? A) Alveolar pressure is greater than atmospheric pressure. B) Intrapleural pressure is greater than alveolar pressure. C) Intrapleural pressure becomes less negative. D) The diaphragm relaxes. E) Lung volume decreases.

Following a few months of noticeably high urine volume, Stephanie's doctor diagnosed her with diabetes insipidus. Stephanie's doctor prescribed her desmopressin, which is a synthetic drug form of which of these hormones? A) ACTH B) Vasopressin C) Atrial natriuretic factor D) Angiotensin II E) Insulin

Following an intense workout your clothes are drenched in sweat. You estimate you lost at least 0.5 L of sweat. Your (similarly sized) friend skipped her workout to donate blood and you found out she donated 0.5 L of plasma. After these activities, which of you will have a greater increase in vasopressin secretion and why? A) You will have a greater vasopressin secretion because sweat is hyperosmotic to plasma. B) You will have a greater vasopressin secretion because sweat is hypoosmotic to plasma. C) Your friend will have a greater vasopressin secretion because sweat is hypoosmotic to plasma. D) Your friend will have a greater vasopressin secretion because sweat is isosmotic to plasma. E) Your friend will have a greater vasopressin secretion because sweat is hyperosmotic to plasma.

If the adrenal glands were removed from a patient, his plasma cortisol levels would ________, secretion of CRH by the ________ would ________, and secretion of ACTH by the ________ would ________. A) increase; hypothalamus; decrease; anterior pituitary gland; decrease B) decrease; hypothalamus; increase; adenohypophysis; increase C) decrease; anterior pituitary gland; increase; hypothalamus; increase D) increase; hypothalamus; increase; adenohypophysis; increase E) decrease; adenohypophysis; increase; anterior pituitary gland; increase

If the pituitary gland is removed from a human subject, which of the following is likely to occur? A) The adrenal gland will hypertrophy to increase cortisol production. B) The adrenal gland will atrophy and plasma cortisol levels will be reduced. C) The hypothalamus will secrete less CRH. D) The subject will remain euthyroid. E) There will be increased negative feedback on growth hormone by insulin-like growth factor 1 (IGF-1).

In the condition diabetes mellitus, why does glucose appear in the urine? A) The plasma concentration of glucose becomes so high that it diffuses from peritubular capillaries into the proximal tubule, down its concentration gradient. B) The filtered load of glucose becomes greater than the tubular maximum for its reabsorption. C) Without the hormone insulin, glucose cannot enter proximal tubule epithelial cells. D) The rate of tubular secretion of glucose becomes greater than the sum of glucose filtration and reabsorption. E) Without insulin, the glomerular filtration barrier becomes extremely leaky to glucose, which is not normally filterable.

The volume of air flowing into the alveoli during inhalation/inspiration is increased when there is an increase in which of these? A) Airway resistance B) The pressure gradient from the atmosphere to the alveoli C) The pressure in the intrapleural space D) The curvature of the diaphragm E) The volume of air in the intrapleural space

To synthesize thyroid hormones, iodine is attached to A) cholesterol. B) the amino acid tyrosine. C) the amino acid tryptophan. D) acetyl coenzyme A. E) the amino acid phenylalanine.

When lying down, a subject's respiratory rate is 12 breaths per minute, his anatomical dead space is 150 mL, and his minute ventilation is 7 L/min. Which of these is closest to his alveolar ventilation in liters per minute? A) 6.0 B) 5.2 C) 4.2 D) 3.0 E) 0.583

Which accurately describes the median eminence of the hypothalamus? A) It is the site of synthesis of adrenocorticotropic hormone (ACTH). B) It is a site where neurohormones are released into blood vessels. C) It is the site where vasopressin is released into blood vessels. D) It is the stalk connecting the hypothalamus to the posterior pituitary. E) It is the main site where thyroid-stimulating hormone first enters the bloodstream.

Which correctly lists a function of estrogens in females and testosterone in males? A) They prevent the pubertal growth spurt. B) They are responsible for epiphyseal plate closure. C) They stimulate the secretion of gonadotropin-releasing hormone (GnRH). D) They stimulate the secretion of luteinizing hormone (LH). E) They stimulate the reabsorption of bone.

Which is NOT an effect of parathyroid hormone? A) Increases the bone-degrading activity of osteoclasts B) Decreases reabsorption of calcium by the kidneys C) Promotes vitamin D synthesis, leading to increased intestinal absorption of calcium D) Increases plasma [Ca2+] E) Decreases reabsorption of phosphate by the kidneys

Which is TRUE about the hormone vasopressin (also known as antidiuretic hormone, ADH)? A) It is a peptide hormone released from the adrenal gland. B) It triggers insertion of aquaporins into the apical membranes of collecting duct cells. C) It promotes the excretion of more water in the urine. D) It stimulates the excretion of K+ in the urine. E) Its main function is to trigger the secretion of aldosterone.

Which is TRUE about the pleural sac? A) It is continuous with the atmosphere and protects the lungs from infection. B) It is a closed sac surrounding each lung that contains only a tiny volume of lubricating fluid. C) It is a closed sac surrounding each lung and contains a large volume of surfactant. D) It is a closed, air-filled space surrounding both lungs that has a negative pressure compared to atmospheric pressure. E) It is bounded by pleural membranes that are very thin, which allows for abundant gas exchange.

Which is TRUE regarding renal tubular reabsorption? A) Reabsorption of Na+ from the proximal tubule occurs as a result of water reabsorption. B) Reabsorption of glucose saturates at a maximum transport rate. C) Urea reabsorption cannot occur at any point along the nephron. D) Toxic substances are removed from the body by reabsorption from peritubular capillaries into the proximal tubule. E) Reabsorption of Na+ only occurs from nephron regions that come after the descending limb of the loop of Henle.

Which is a result of elevated thyroid hormone levels? A) An increase in triglyceride storage B) Increased Na+/K+ ATPase activity C) Decreased body temperature D) Mental lethargy

Which is characteristic of a person chronically suffering from hypoxic hypoxia? A) Higher-than-normal alveolar PO2 B) Higher-than-normal hematocrit C) Higher-than-normal arterial PO2 D) Lower-than-normal lactic acid production E) Lower-than-normal blood flow through tissues

Which is most likely a characteristic of cells that secrete steroid hormones? A) They store large amounts of hormone. B) They are characterized by abundant smooth endoplasmic reticulum and few secretory granules. C) They contain large numbers of secretory granules. D) They are found in the anterior pituitary gland. E) They are found in the medulla of the adrenal gland.

Which of the following are chemoreceptors? A) Hair cells in the cochlea B) Receptors in the aortic and carotid bodies C) Baroreceptors in the aortic and carotid arch D) Receptors that mediate the Hering-Breuer reflex

Which of the following does NOT correctly describe kidney function? A) They contribute significantly to long-term regulation of arterial blood pressure by maintaining the proper plasma volume. B) They produce urine of a constant composition at all times, in order to maintain homeostasis of extracellular fluid. C) They excrete metabolic waste products. D) They assist in maintaining proper acid-base balance in the body. E) They secrete hormones.

Which of the following drugs, administered as an aerosol spray, would be most likely to help a patient during an asthmatic attack? A) Pulmonary surfactant B) A β2-adrenergic agonist C) A muscarinic agonist D) Histamine E) A β2-adrenergic antagonist

Which of the following hormones is NOT usually secreted at higher levels in response to stress? A) Aldosterone B) Gonadotropins C) Vasopressin D) Antidiuretic hormone (ADH) E) Beta-endorphin

Which of the following is TRUE regarding pituitary growth hormone (GH)? A) The liver produces a factor that mediates the metabolic actions of GH. B) GH stimulates insulin-like growth factor-1 (IGF-1) production by the liver and by many other cells. C) GH increases the sensitivity of tissues to the action of insulin. D) GH exerts negative feedback on its own production by inhibiting the hypothalamic secretion of somatostatin. E) IGF-1 stimulates the secretion of GH by anterior pituitary gland cells.

Which of the following is a cause of asthma? A) Loss of alveoli B) Inflammation of the bronchioles C) Elevation of intrapleural pressure to equal atmospheric pressure D) Environmental chemicals that stimulate β2-adrenergic receptors E) Lack of pulmonary surfactant

Which of the following is least likely to be filtered into Bowman's capsule in a normal, healthy person? A) Glucose B) Plasma protein C) Sodium D) Urea E) Bicarbonate ion

Which of the following most accurately describes the renal transport of Na+? A) Na+ is actively transported in all segments of the tubule. B) Primary active transport of Na+ allows for secondary active transport of glucose and H+ in the proximal tubule. C) Most of the Na+ transport occurs in the distal convoluted tubule and collecting ducts. D) Na+ is actively secreted into the nephron lumen by cells in the cortical collecting ducts. E) Na+ is actively transported across the luminal membrane of proximal tubule cells in exchange for K+, by Na+/K+ ATPase pumps.

Which of the following organs is the main site of aldosterone secretion? A) Kidneys B) Adrenal glands C) Systemic and pulmonary blood vessels D) Liver E) The atria of the heart

Which of the following statements about hormones is correct? A) Anterior pituitary hormones are synthesized in the hypothalamus. B) All hormones secreted by the anterior and posterior pituitary glands are peptides. C) IGF-1 stimulates growth by increasing growth hormone secretion through positive feedback. D) All of the hypophysiotropic hormones are peptides. E) Only steroid hormones can regulate the secretion of steroid hormones.

Which of the following statements about oxytocin is TRUE? A) Target cells of oxytocin have receptors for the hormone in their nucleus. B) Oxytocin is synthesized in the hypothalamus. C) Oxytocin is secreted by the anterior pituitary gland. D) Oxytocin's main function is to increase the rate of respiration. E) Oxytocin keeps uterine smooth muscle from contracting, so it prolongs pregnancy.

Which of the following statements regarding pulmonary surfactant is TRUE? A) It is secreted by type I alveolar cells. B) It increases the compliance of the lungs. C) It increases airway resistance. D) It is secreted into the intrapleural space. E) It can only interact with other lipid molecules.

Which of the following would cause a decrease in the binding affinity of hemoglobin for oxygen? A) Increased pH of the blood B) Increased temperature of the blood C) Decreased DPG levels in erythrocytes D) The presence of carbon monoxide E) Decreased concentration of H+ in the blood

Which of these is demonstrated by the oxygen-hemoglobin dissociation curve? A) The greater the PO2 of the blood, the greater the dissociation of O2 from hemoglobin. B) At normal resting systemic arterial PO2, hemoglobin is almost 100% saturated with oxygen. C) At normal resting systemic venous PO2, only about 75% of the hemoglobin is in the form of deoxyhemoglobin. D) More additional oxygen binds to hemoglobin when going from a PO2 of 60 to 100 mmHg, than is added when going from a PO2 of 40 to 60 mmHg. E) As PO2 increases, the saturation of hemoglobin with oxygen increases linearly.

Which statement best describes the manner in which growth hormone stimulates cell proliferation? A) It directly stimulates cell division in most tissues. B) It stimulates the release of insulin-like growth factor I (IGF-1) from the liver and other target tissues of growth hormone. C) It stimulates metabolism. D) It stimulates the release of eicosanoids from lymphoid tissues. E) It stimulates sleep.

Which stimulates the secretion of growth hormone? A) Waking from sleep B) Exercise C) Increased levels of IGF-I in blood D) High plasma glucose E) Increased somatostatin secretion

You are a scientist at a drug company where your CEO has asked for your team to create a drug that will inhibit spontaneous emptying of the bladder (incontinence). Which of the following drugs would be effective? A) A drug that enhances the effects of parasympathetic neurons on the detrusor muscle B) A drug that blocks the effects of parasympathetic neurons on the detrusor muscle C) A drug that inhibits the effects of sympathetic neurons on the internal urethral sphincter D) A drug that inhibits the effects of somatic neurons on the bladder E) A drug that inhibits the action of sympathetic neurons on the external urethral sphincter

You are an EMT and arrive at the scene of an opioid overdose. The overdose victim is breathing extremely slowly and shallowly. When you arrive at the ER, you report that the medical team should watch out for signs of A) metabolic acidosis. B) respiratory acidosis. C) metabolic alkalosis. D) respiratory alkalosis.

You embark on a hiking trip on Mt. Kilimanjaro (altitude = 19,000 ft; Atmospheric air pressure = 379 mmHg). As you ascend, what happens to the PO2 in the alveoli? A) No change from sea level, as long as we breathe in the same volume of air. B) Alveolar PO2 decreases. C) Alveolar PO2 increases.

You embark on a hiking trip on Mt. Kilimanjaro (altitude = 19,000 ft; Atmospheric air pressure = 379 mmHg).mHg). As you ascend, what are you likely to notice about your breathing? A) You need to work to exhale, using your muscles to decrease your thoracic size beyond what is normal B) You need to work harder to inhale, expanding your thoracic size beyond what is normal C) Both would happen D) Neither would happen

You have a patient complaining of fatigue and lethargy. She mentions that she recently went on a low-salt, all carbohydrate diet and consumes mostly rice. You notice a swelling in her neck. You order some blood work. Which of the following do you expect? A) Low plasma concentration of thyroid hormones and thyroid-stimulating hormone (TSH) B) Low plasma concentration of thyroid hormones C) High plasma concentration of thyroid-stimulating hormone (TSH) but low thyrotropin-releasing hormone (TRH) D) High plasma concentration of thyroid hormones due to increased secretion of TSH by the pituitary gland E) Low plasma concentration of thyroid hormones and atrophy of the thyroid gland due to reduced concentrations of thyroid-stimulating hormone (TSH)

You're studying long-term stress in foster children. One thing you find is that, among the children experiencing the most significant stress for the longest period of time is decreases in ________. A) circulating cortisol levels B) bone and muscle density C) blood glucose levels D) adrenal gland function

You've just stepped on the treadmill and are beginning to increase your speed. As you reach your maximum, which of the following values will NOT increase? A) Minute ventilation B) Arterial PCO2 C) Oxygen delivery to muscles D) Oxygen extraction from the blood by muscles E) Body heat production

97) Syndrome R involves a genetic mutation that affects all chemoreceptors in the body. Which sensations are affected in Syndrome R? A) Hearing B) Taste C) Pain D) Smell E) Touch

B, C, D

71) Which of the drug treatments listed below is INCORRECTLY matched to a mode of action in treating hypertension? A) Alpha-adrenergic receptor blockers—reduce TPR by decreased stimulation of arteriolar smooth muscle B) Beta-adrenergic receptor antagonists—reduce cardiac output by slowing heart rate and reducing contractility C) Antagonists of parasympathetic receptors—reduce TPR by decreased stimulation of arteriolar smooth muscle D) Angiotensin-converting enzyme (ACE) inhibitors—reduce TPR by reducing angiotensin II concentrations E) Diuretics—reduce blood volume by increasing excretion of sodium and water in urine F) Calcium channel blockers—reduce speed and force of contraction in vascular smooth muscle G) ACE inhibitors—lowers peripheral resistance by promoting vasodilation

76) Which is an intermediary protein that enables platelets to adhere to collagen? A) Tissue plasminogen activator (t-PA) B) ATP C) von Willebrand factor (vWF) D) Arachidonic acid E) Activated protein C

79) Which of the following statements about blood clotting is FALSE? A) It is the formation of a thrombus. B) It occurs after formation of a platelet plug in a damaged vessel. C) It requires the presence of erythrocytes. D) It is a result of a cascade of enzyme activation. E) It involves positive feedback by thrombin.

A patient goes to her doctor, complaining of fatigue, weight gain, and intolerance to cold. She also has a noticeable goiter in her neck. Which of the following is a most likely diagnosis and cause? A) She has hypothyroidism, possibly due to destruction of thyrotrope cells of her anterior pituitary gland. B) She has hyperthyroidism, possibly due to Graves' disease. C) She has hypothyroidism, possibly due to low iodine in her diet. D) She has hyperthyroidism, possibly due to a hypersecreting tumor of the anterior pituitary gland.

Acting alone, epinephrine and thyroid hormone each stimulates release of only a small amount of fatty acids from adipose cells. In the presence of thyroid hormone, epinephrine causes a much more substantial release of fatty acids from the cells. What is the term describing the effect of thyroid hormone on epinephrine's actions? A) Antagonistic B) Agonistic C) Permissive D) Direct E) Paracrine

After prolonged exertion in a hot climate, baroreceptors would ________ firing, leading to ________ secretion of ________ and thus ________ renal reabsorption of ________. A) increase; increased; renin; increased; Na+ B) decrease; increased; renin; decreased; Na+ C) decrease; increased; vasopressin; increased; water D) increase; decreased; vasopressin; decreased; water E) decrease; decreased; vasopressin; increased; water

At what time in the lifespan is growth hormone secretion rate highest? A) In utero B) During childhood C) During adolescence D) During adulthood E) During senescence

Compared to the normal plasma osmolarity, the tubular fluid is ________ as it enters Bowman's space, ________ at the beginning of the loop of Henle, ________ at the tip of the loop, and ________ at the beginning of the distal convoluted tubule. A) isosmotic; hyperosmotic; hyperosmotic; isosmotic B) isosmotic; isosmotic; hypoosmotic; hypoosmotic C) isosmotic; isosmotic; hyperosmotic; hypoosmotic D) isosmotic; isosmotic; hypoosmotic; hyperosmotic E) isosmotic; isosmotic; hyperosmotic; isosmotic

Deficiency of iodine in the diet results in ________ caused by ________. A) a goiter; increased production of thyroid-stimulating hormone (TSH) and increased thyroid hormone levels B) atrophy of the thyroid gland; loss of negative feedback by thyroid hormones and increased thyroid-stimulating hormone (TSH) levels C) a goiter; loss of negative feedback by thyroid hormones and increased thyroid-stimulating hormone (TSH) levels D) atrophy of the thyroid gland; decreased sensitivity of receptors for thyroid-stimulating hormone (TSH) E) atrophy of the anterior pituitary gland; loss of negative feedback by thyroid hormones

How does the renal countercurrent multiplier mechanism allow the creation of a concentrated urine? A) It transports NaCl from the medullary interstitial fluid into the collecting duct, which directly increases the osmolarity of the urine. B) It transports urea from the medullary interstitial fluid into the collecting duct, which directly increases the osmolarity of the urine. C) By concentrating NaCl in the renal medullary interstitial fluid, it allows water to be reabsorbed from the collecting ducts when vasopressin is present. D) By pumping NaCl and urea into the ascending limb of the loop of Henle, it raises the solute load, which turns into a concentrated urine once water is extracted from the collecting duct. E) When anti-diuretic hormone is present, it stimulates the pumping of NaCl from the medullary interstitial fluid and water follows, concentrating the urine.

Jerome has had too many alcoholic drinks at a party. One of the effects of alcohol is that it inhibits the release of vasopressin. Which of the following is Jerome likely to notice? A) A reduction in urine volume B) The excretion of glucose in the urine increased C) High volume of dilute urine D) Very concentrated urine E) An increase in blood pressure

Maria is a patient in the ward who was recently in a motor vehicle accident. Her injuries are causing her a lot of pain, and as a consequence to the morphine she's been given, her respiratory rate is quite low. Which of the following is likely to be TRUE? A) The pH of her blood has increased. B) The level of O2 in her blood has increased. C) The level of H+ ions in her blood has increased. D) The alveolar CO2 has decreased to near atmospheric levels. E) The alveolar O2 level has increased toward atmospheric levels.

Short-loop negative feedback occurs when hormones from the ________ inhibit hormone secretion by the ________. A) hypothalamus; anterior pituitary B) adrenal cortex; hypothalamus C) anterior pituitary; hypothalamus D) adrenal cortex; anterior pituitary E) anterior pituitary; adrenal cortex

What brain center has neurons that fire mainly during inspiration and have input to the spinal motor neurons that activate the diaphragm and inspiratory intercostal muscles? A) The ventral respiratory group of the medulla oblongata B) The pre-Bötzinger complex C) The dorsal respiratory group of the medulla oblongata D) The pneumotaxic center of the pons E) The apneustic center of the pons

What is the definition of a prohormone? A) Hormones that bind to endocrine glands and stimulate the secretion of a second hormone B) Hormones that bind to endocrine glands and inhibit the secretion of a second hormone C) A longer protein or peptide that is cleaved into shorter ones, at least one of which is a peptide or protein hormone D) Hormones that stimulate the expression of receptors for a second hormone, promoting their action E) Steroid hormones that are inactivated by having hydroxyl groups removed from their structure

What is the rate-limiting (regulated) step for stimulating the secretion of aldosterone? A) Conversion of angiotensin I to angiotensin II in the blood B) Secretion of angiotensinogen by the liver C) Conversion of angiotensinogen to angiotensin I in the blood D) Secretion of ACTH by the anterior pituitary E) Secretion of angiotensin II by the kidney

What region of the nephron reabsorbs about two-thirds of filtered Na+ and Cl-? A) Ascending loop of Henle B) Glomerulus C) Proximal convoluted tubule D) Distal convoluted tubule E) Collecting duct

What term describes hormones secreted by the hypothalamus that regulate the secretion of hormones from the anterior pituitary gland? A) Growth factors B) Paracrine factors C) Hypophysiotropic hormones D) Metabotrobic-releasing factors E) Cerebrovitalistic hormones

What term describes hormones that influence the secretion of other hormones? A) Mineralocorticoids B) Antagonistic C) Tropic D) Allosteric E) Teratogen

Which correctly describes the cause of the increase in alveolar ventilation that occurs when a person ascends to high altitude? A) The decrease in PCO2 of inspired air decreases alveolar PCO2, stimulating the peripheral chemoreceptors. B) The decrease in PCO2 of inspired air decreases alveolar PCO2, stimulating the central chemoreceptors. C) The decrease in PO2 of inspired air decreases alveolar and arterial PO2, stimulating the peripheral chemoreceptors. D) The decrease in total atmospheric pressure causes a greater negative pressure in the intrapleural space, resulting in deeper and more frequent breathing. E) The decrease in the total barometric pressure at high altitude causes hypocapnea, which stimulates peripheral chemoreceptors.

Which does NOT apply to hormones? A) They are chemical regulators that are conveyed from one organ to another via the bloodstream. B) In some cases, the same chemical substances can also function as local regulators and/or neurotransmitters. C) All hormones are derived from cholesterol. D) They are secreted into the blood by ductless glands. E) They are sometimes secreted by neural tissue.

Which is a result of an absence of thyroid hormones during fetal development? A) Acromegaly B) Cushing's syndrome C) Congenital hypothyroidism (cretinism) D) Graves' disease E) Addison's disease

Which is an accurate description of the posterior pituitary and its functions? A) It is glandular tissue and secretes vasopressin and prolactin. B) It is neural tissue and is stimulated to secrete oxytocin and vasopressin by hypophysiotropic hormones. C) It is neural tissue, and vesicles containing oxytocin and vasopressin are transported to axon terminals there. D) It is glandular tissue and releases oxytocin and somatostatin when action potentials arrive along axons from the hypothalamus. E) It is neural tissue that secretes hypophysiotropic hormones that control the secretion of the anterior pituitary hormones.

Which is an example of long-loop negative feedback? A) Stimulation of dopamine release by prolactin B) Inhibition of growth hormone-releasing hormone (GHRH) release by growth hormone (GH) C) Inhibition of growth hormone-releasing hormone (GHRH) release by insulin-like growth factor-1 D) Inhibition of corticotropin-releasing hormone by adrenocorticotropic hormone (ACTH) E) Stimulation of thyroid-stimulating hormone (TSH) release by thyrotropin-releasing hormone (TRH)

Which of the following describes tubular reabsorption in the kidney? A) The movement of substances from the peritubular capillaries into the tubular fluid B) The movement of substances from the proximal tubule into the loop of Henle C) Transepithelial transport from the lumen of the tubule into renal interstitial fluid D) Movement of Na+, Cl-, and water from glomerular capillaries into Bowman's capsule E) Transport of solutes from the renal medullary interstitial fluid into the collecting duct

Which of the following is NOT stimulated by cortisol during stress? A) Gluconeogenesis B) Protein catabolism C) Glucose uptake into muscle cells D) Triglyceride catabolism in adipose cells E) Decreased sensitivity to insulin

Which of the following is TRUE during the initial stage of an asthma attack? A) ΔP is increased. B) ΔP is decreased. C) R is increased. D) R is decreased. E) None of these, flow rate is unchanged during an asthma attack.

Which of the following statements about the response of arteriolar smooth muscle to changing oxygen partial pressures is TRUE? A) Both systemic and pulmonary arterioles respond to a decrease in PO2 by constricting. B) Both systemic and pulmonary arterioles respond to a decrease in PO2 by dilating. C) Systemic arterioles respond to a decrease in PO2 by dilating, but pulmonary arterioles constrict in response to decreased PO2. D) Systemic arterioles respond to a decrease in PO2 by constricting, but pulmonary arterioles dilate in response to decreased PO2. E) Changes in PO2 do not affect arteriolar smooth muscle in the pulmonary system.

Which of the following statements regarding control of respiration is correct? A) A slight decrease in arterial PO2 is a stronger stimulus for increased ventilation than is a comparable decrease in arterial PCO2. B) The most important signal for regulating ventilation is the H+ concentration of arterial blood. C) Increased concentrations of lactic acid stimulate ventilation primarily by acting on peripheral chemoreceptors. D) An increase in the HCO3- concentration in blood stimulates ventilation. E) At high altitude, a decrease in PCO2 of the blood stimulates an increase in ventilation.

Which of the following substances undergoes renal tubular secretion? A) Ca2+ B) Na+ C) K+ D) H2O

Which of the following would occur if a person lost the ability to synthesize vasopressin? A) The ability to reabsorb water in the proximal tubule would be lost. B) The excretion of glucose in the urine would increase. C) The urine would become hypoosmotic compared to plasma. D) The urine production would decrease dramatically, and the urine osmolarity would be hypertonic compared to plasma. E) Blood pressure would increase significantly.

Which of these causes inhalation/inspiration? A) Increase in the curvature (upward movement) of the diaphragm B) Movement of the ribs closer together due to contraction of the internal intercostal muscles C) Flattening (downward movement) of the diaphragm D) Contraction of the abdominal muscles E) Alveolar pressure increasing above atmospheric pressure

Which of these correctly describes the chloride shift? A) In the lungs, chloride enters red blood cells in exchange for bicarbonate ions. B) In the tissues, chloride exits red blood cells in exchange for carbonic acid. C) In the tissues, chloride enters red blood cells in exchange for bicarbonate ions. D) In the lungs, chloride enters red blood cells in exchange for CO2. E) In the tissues, chloride enters red blood cells in exchange for CO2.

Which would result from a vitamin D deficiency? A) Hypercalcemia B) An increase in bone mass C) An increase in parathyroid hormone levels D) Increased intestinal absorption of calcium

You (a healthy individual) are swimming underwater when you can no longer resist the urge to breathe. This overwhelming urge is probably due to A) the autorhymthic cells in your diaphragm contracting. B) the decrease in O2 available to the cells of the body. C) the increase in plasma H+. D) the increase in pH has made your blood dangerously alkaline.

You have a patient with extensive birth defects that affect the kidney anatomy. Nevertheless, she does have some kidney function. One thing you've noticed in her labs is extremely low renin secretion. Which of the following anatomical locations is likely to exhibit abnormal development? A) The ascending limb of the loop of Henle B) The glomerular capillaries C) The juxtaglomerular apparatus D) The proximal tubule E) The efferent arteriole

You have discovered a novel steroid hormone. You'd like to isolate its receptor as part of your next project. Where should you look first? A) On the cell surface B) In the blood stream C) In the cytoplasm D) Any of these might be places where the receptor could be found.

You're resting on the couch watching TV. Which of the following is the most likely reflection of the values in your body? Regarding the partial pressures of O2 and CO2, which of the following statements is true in a normal person at rest? A) Atmospheric PO2 is approximately 100 mmHg and the alveolar PO2 is approximately 160 mmHg. B) The PCO2 in the air is approximately 40 mmHg and the alveolar PCO2 is approximately 60 mmHg. C) The PO2 in the systemic arteries is approximately 100 mmHg and the alveolar PO2 is approximately 105 mmHg. D) PCO2 in the systemic veins is less than systemic arterial PCO2. E) PCO2 in the pulmonary arteries is less than pulmonary venous PCO2.

96) To see an object, for example a cat, and know that it is a cat that you have seen before, your brain receives and associates the visual input. Which brain areas are involved? A) Auditory cortex B) Somatosensory cortex C) Visual cortex D) Occipital lobe association area E) Parietal lobe association area

C, D

1) Which of the following statements regarding sensory systems is correct? A) All sensory information that reaches the brain can be experienced as a conscious sensation. B) Sensory information that leads to conscious awareness of the stimulus is called transduction. C) The term "sensory unit" refers to a group of receptors that receive a particular stimulus and the afferent neuron associated with those receptors. D) The term "adequate stimulus" means that a stimulus is strong enough to be detected. E) Some sensory receptors are modifications of the peripheral endings of efferent neurons.

10) Which of these is one reason you can distinguish between a needle prick on the foot and an ice cube on the wrist? A) The ice cube stimulates a different class of receptors than the needle prick, even though both signals go to exactly the same location in the brain. B) The action potentials from the needle prick are inherently different from the impulse generated by the ice cube. C) The region of the brain to which one receptor pathway leads is different from the region to which the other pathway leads. D) The needle prick generates a stronger action potential in any one neuron than an ice cube does. E) The needle prick generates a higher frequency of action potentials than the ice cube does.

19) Which of the following symptoms would a patient with a lesion (injury) that destroyed the right side of the spinal cord in the region of the upper back be most likely to experience? A) Loss of both pressure sense and pain in the right foot B) Loss of both pressure sense and pain in the left foot C) Loss of pressure sense in the right foot and pain in the left foot D) Loss of pressure sense in the left foot and pain in the right foot

2) The alpha rhythm is the most prominent EEG pattern when an adult is A) in REM sleep. B) in non-REM sleep. C) awake and relaxed with eyes open. D) awake and thinking hard about something.

2) What is the term that describes the production of red blood cells? A) Hemaglutination B) Erythrocytosis C) Erythropoiesis D) Erythroblastosis E) Hemostasis

2) Which is TRUE about receptor potentials? A) They are action potentials. B) They always trigger action potentials. C) They vary in magnitude with stimulus strength. D) They propagate without decrement. E) They generally occur at the axon hillock of afferent neurons.

21) If the lens flattened with age, what type of vision would become easier over time for this individual? A) Both near and distance vision are fine, but changing back and forth between them becomes difficult B) Near vision (e.g., reading a book) C) Distance vision (e.g., reading a street sign) D) Both near and distance vision are compromised E) No light will enter the eye and blindness will result

21) Which of the following statements about the refractory period of neuronal or muscle membranes is TRUE? A) In nerve cells, the absolute refractory period coincides with the period of increased K+ permeability. B) In skeletal muscle cells, the absolute refractory period lasts about as long as the twitch. C) In ventricular cells, the absolute refractory period coincides with the period of increased Na+ and Ca2+ permeability. D) The relative refractory period in neuronal membranes lasts about the same length of time as the absolute refractory period in cardiac muscle cell membranes. E) The refractory period in an alpha-motor neuron membrane is much briefer than the refractory period in a skeletal muscle cell membrane.

22) A person whose lens focuses light from distant objects in front of (rather than on) the retina has a condition called A) presbyopia. B) hyperopia. C) myopia. D) cataract. E) glaucoma.

22) Which of the following statements about the cardiac cycle is TRUE? A) The duration of systole is greater than that of diastole in a subject at rest. B) During isovolumetric ventricular relaxation, blood flows from the atria into the ventricles. C) Closure of the atrioventricular valves occurs at the beginning of ventricular systole. D) The QRS complex occurs at approximately the same time as the closure of the semilunar valves. E) The first valves to go from closed to open after the atrial kick are the atrioventricular valves.

23) Which of the following statements regarding vision is FALSE? A) The cornea refracts light rays more strongly than the lens. B) Presbyopia is a condition in which the lens cannot accommodate adequately for near vision. C) Myopia is a condition in which the lens focuses light from distant objects behind the retina. D) Cataract is an increase in opacity (clouding) of the lens. E) The image of an object that is focused on the retina is upside down relative to the object's actual position in space.

23) Which of these occurs during an isometric contraction of a skeletal muscle? A) The I bands shorten and the A bands stay the same length. B) The thick and thin filaments slide past each other. C) Sarcomere length does not change significantly. D) The A bands shorten and the I bands stay the same length. E) Cross-bridges lock onto actin, similar to what occurs in rigor mortis.

23) You and your colleague are medical technicians in a cardiac function lab. You are reading the ECG of a patient and your friend is trying to capture an image of the AV valves opening using an ultrasound. At what point should you tell your friend to start recording images? A) Just before the P wave B) Just after the P wave C) At the beginning of the QRS complex D) Just before the T wave E) After the T wave

24) During an isometric twitch in a skeletal muscle A) tension generated by the muscle always exceeds the load on the muscle. B) tetanus occurs. C) sarcomeres do not significantly shorten. D) the whole muscle shortens. E) H zones shorten.

26) A person with bilateral damage to the hippocampus will probably A) suffer from aphasia. B) develop symptoms of Parkinson's disease. C) suffer impairment of consolidation of declarative memory. D) have difficulty learning new physical skills. E) experience all of the choices.

26) Which of the following statements about rods and cones in the retina is TRUE? A) Cones enable us to see in dim light, rods provide color vision. B) Rods and cones all have the same kind of opsin. C) Cones are found in highest density in the fovea, rods are more prevalent near the edges of the retina. D) Rods require brighter light to activate them than do cones. E) Rods provide higher visual acuity than do cones.

28) The membrane potential of rod and cone cells is around A) -70 mV in the dark, and the cells depolarize in the light. B) -70 mV in the dark, and the cells hyperpolarize in the light. C) -35 mV in the dark, and the cells hyperpolarize in the light. D) -35 mV in the dark, and the cells depolarize in the light.

29) Compared to humans, cats have excellent night vision. Which of the following might contribute to their ability to see in the dark? A) Compared to the human eye, cats have more kinds of cone photoreceptors. B) The lateral geniculate nucleus of a cat contains opponent color cells. C) Cats have more kinds of rod photoreceptors than humans. D) Cats have more kinds of chromophores. E) In cats, cone photoreceptors are concentrated in the fovea.

3) During concentric isotonic contraction of a skeletal muscle fiber, which of these occurs? A) Sarcomeres lengthen B) A bands shorten C) I bands shorten D) A bands lengthen E) Thin filaments shorten

3) Your friend is poking your skin with two pins a few millimeters apart at the same time. Visually, you can see there are two pins, but you can only feel a single pen poke. This is probably because: A) both pens are activating the same receptor. B) both afferent neurons converge on the same interneuron. C) the receptors in both skin areas utilize the same afferent neuron. D) both sensations are grouped together in the somatosensory cortex.

30) Sinoatrial node cells A) reach threshold only when action potentials generated by the AV node arrive through gap junctions. B) exhibit spontaneous depolarization that is speeded by activation of their cholinergic receptors. C) exhibit spontaneous depolarization that is speeded by activation of their beta-adrenergic receptors. D) exhibit a steep upstroke due to the presence of the same type of Na+ channels found in neuronal membranes. E) are between atrial muscle cells and cells of the bundle of His.

30) When a muscle has been repeatedly contracting at a moderate intensity for an extended period of time (more than a few minutes), what is the primary source of ATP? A) Transfer of energy and phosphate from creatine phosphate to ADP B) Glycolysis C) Oxidative phosphorylation D) Breakdown of myosin E) Uptake of ATP from the blood plasma

30) When a person loses consciousness, working memory is interrupted and memories are abolished for all that happened for a variable period of time before the blow that caused unconsciousness. Why? A) The traumatic blow to the head caused a concussion through violent displacement of the brain in the skull. B) There was a deficiency of adequate blood flow to the brain. C) There was an interruption in the constant stream of neuron potentials to memory facilitation brain areas. D) Conflicting external interference prevents conversion of short-term to long-term memory. E) This is an area of neurological research that has not achieved any satisfying conclusions at the present time.

32) Damage to the part of the brain known as Broca's area is likely to A) cause difficulty in recognizing faces. B) be associated with paralysis on the left side of the body. C) impair speech. D) Both "cause difficulty in recognizing faces" and "be associated with paralysis on the left side of the body" are correct. E) Both "be associated with paralysis on the left side of the body" and "impair speech" are correct.

32) What is described by the Frank-Starling mechanism of the heart? A) The relationship between end-diastolic volume and heart rate B) The relationship between end-systolic volume and stroke volume C) The relationship between length and tension in cardiac muscle cells D) The relationship between sympathetic stimulation and stroke volume E) The relationship between arterial blood pressure and stroke volume

34) During the course of a ride on a roller coaster, what would be FALSE regarding your heart? A) An increase in heart rate B) A decrease in the duration of systole C) A decrease in the slope of the pacemaker potential D) An increase in the amount of Ca2+ entering cardiac muscle cells E) An increase in the rate of cross-bridge cycling in ventricular muscle cells

34) The muscles in your fingers have a predominance of fast-glycolytic fibers, whereas the muscles of your feet have a predominance of slow-oxidative fibers. Which of the following statements accurately describes their differences? A) The muscle fibers of the feet have a greater abundance of glycogen than do the muscle fibers of the hands. B) Muscle fibers of the feet have a greater abundance of myoglobin than do muscle fibers of the hands. C) Muscle fibers of the hands can generate greater tension than muscle fibers of the feet. D) Muscle fibers in both locations are innervated by alpha motor neurons of the same diameter. E) More oxidative phosphorylation occurs in the hands than the feet.

38) The actual receptors for hearing are called A) baroreceptors. B) nociceptors. C) hair cells. D) Pacinian corpuscles. E) somatic receptors.

4) Which of the following statements regarding contraction of a skeletal muscle fiber is TRUE? A) Thick filaments shorten when muscle cells contract. B) Some contractions occur without cross-bridge activation. C) Contracting muscle fibers do not always shorten. D) Contraction does not always require the occurrence of an action potential. E) Contraction only occurs following summation of action potentials from many motor neurons.

43) Which of the following statements is FALSE? A) Synaptic input onto skeletal muscle cells is always excitatory, whereas inputs to smooth muscle cells may be either excitatory or inhibitory. B) A single smooth muscle cell may be innervated by both a sympathetic neuron and a parasympathetic neuron. C) Contractile activity of smooth muscle cells does not normally require Ca2+. D) In the absence of any neural input, skeletal muscle cannot generate tension. E) Ca2+ that activates contraction of smooth muscles can come from either the ECF or from the sarcoplasmic reticulum.

44) You are in a car that stops suddenly. Your head jerks forward, then returns to its original position. Your brain is able to interpret this motion because of the action of ________ cells in the ________. A) retinal, cochlea B) hair, saccule C) hair, semicircular canals D) ganglion, olfactory mucosa E) basiliar, tectorial membrane

45) Which is a TRUE statement about smooth muscle? A) Smooth muscle is striated. B) Smooth muscle does not have thick and thin filaments. C) Smooth muscle does not use troponin-tropomyosin to regulate cross-bridge activity. D) Changes in cytosolic calcium do not regulate cross-bridge activity in smooth muscle. E) The myosin in smooth muscle requires phosphorylation before it can bind to ATP.

45) Which of the following correctly compares the factors involved in bulk flow of fluid in systemic and pulmonary capillaries? A) The protein oncotic pressure inside pulmonary capillaries is significantly greater. B) There are no lymphatic vessels to remove fluid from lung interstitial fluid. C) The hydrostatic pressure inside pulmonary capillaries is significantly lower. D) The protein oncotic pressure is lower in pulmonary interstitial fluid than in typical systemic interstitial fluid. E) The Starling's forces overwhelmingly favor reabsorption all along the length of pulmonary capillaries.

5) In skeletal muscle cells, calcium initiates contraction by binding to A) tropomyosin. B) actin. C) troponin. D) myosin. E) the thick filament.

52) Tina is a hard-working sales clerk in a busy department store. She has stood completely still behind the check-out counter for an 8-hour shift. At the end of Tina's shift, she finds that she feels somewhat dizzy and guesses that her blood pressure is quite low. When Tina gets home she also notices that her ankles are swollen. What physiological issue is most likely to blame in this scenario? A) Lymphatic blockage in her lower legs B) High osmotic pressure in her lower leg capillaries C) High hydrostatic pressure in lower leg capillaries D) Reactive hyperemia to lower leg tissues E) None of these, the swelling is unrelated to cardiovascular issues

54) You are trying to design a new drug to painlessly euthanize animals. Your plan is to design a molecule that blocks the action of one of the following pumps so that heart muscle stays contracted and blood movement is stopped. Which would be effective? A) Ca 2+-ATPase pumps on the cell membrane B) Na+/K+-ATPase pumps on the cell membrane C) Ca2+-ATPase pumps on the sarcoplasmic reticulum D) Na+/Ca2+-exchangers on the cell membrane E) None of these would result in sustained muscle contraction

55) Which best describes a role of L-type Ca2+ channels in cardiac muscle cells? A) They function exactly the same in cardiac muscle cells as they do in skeletal muscle. B) They are directly responsible for making cardiac muscle fatigue-resistant. C) They are responsible for preventing tetanic contractions. D) They cause the absolute refractory period to be very brief. E) They act as non-conducting voltage sensors that mediate excitation-contraction coupling.

6) Certain smells can trigger shifts in emotional state (for example, the smell of a familiar place or a loved one's clothing) because specific olfactory pathways synapse in the ________. A) frontal lobes of the cerebral cortex B) somatosensory cortex C) limbic system D) temporal lobes of the cerebral cortex E) occipital lobes of the cerebral cortex

6) You are a sleep lab technician and are sorting through the records obtained the previous night. You found that at 1:20 a.m. EEG tracings showed low amplitude, high-frequency activity, and subject had very low muscle tone. Which of the following is likely? A) The subject was easily awakened and did not report dreaming. B) She was difficult to awaken and did not report dreaming. C) Once she was awake she reported dreaming. D) She was already awake at 1:20am.

61) How would a hemorrhage immediately affect the activity of the baroreceptors? A) The baroreceptors would increase their rate of firing to all medullary cardiovascular center cell types. B) The baroreceptors would increase their rate of firing to cells in the medulla oblongata that activate sympathetic pathways and decrease their rate of firing to cells in the medulla oblongata that activate parasympathetic pathways. C) The baroreceptors would decrease their rate of firing to all medullary cardiovascular center cell types. D) The baroreceptors would decrease their rate of firing to cells in the medulla oblongata that activate sympathetic pathways and increase their rate of firing to cells in the medulla oblongata that activate parasympathetic pathways. E) A hemorrhage would not affect the activity of the baroreceptors.

62) Which of the following is most likely to occur when a soldier stands at attention—very still, with legs and spine straight? A) Decreased pressure in the capillaries of the feet B) Increased absorption of interstitial fluid by the capillaries of the feet C) Increased storage of blood in the veins of the feet and legs D) Increased venous return E) Increased blood flow to the brain

63) During exercise, there is a decreased flow of blood to A) the brain. B) the skin. C) the abdominal organs. D) the skeletal muscles E) the heart.

65) Which of the following does NOT contribute to increased stroke volume during exercise? A) Increased contractility of cardiac muscle B) Increased venous return C) Increased length of filling time during diastole D) Increased sympathetic stimulation of ventricular muscle E) Increased end-diastolic volume

68) Which of the following does NOT describe hypertension? Hypertension A) refers to a chronic state of elevated blood pressure. B) is usually defined as a systolic pressure greater than 140 mmHg and a diastolic pressure greater than 90 mmHg. C) is usually a result of chronically elevated cardiac output. D) may be caused by kidney disease. E) can sometimes be treated with drugs that increase excretion of water in the urine.

7) Which of the descriptions is not descriptive of REM (rapid eye movement) sleep? A) Visible movements of the eyes resembling those of one tracking the movements of objects in space, watching TV, and so on B) Difficulty arousing the sleeper C) Oxygen consumption decreases by comparison to NREM sleep and in an alert wakeful state. D) It represents 20-25% of a person's "sleeptime." E) Skeletal muscle activity is markedly reduced, except for the extraocular and respiratory muscles.

33) In the visual pathway providing sensory action potentials to the brain, the first cells that are capable of initiating action potentials are A) cone cells. B) rod cells. C) lateral geniculate cells. D) ganglion cells. E) bipolar cells.

34) If the pH of the vitreous humor decreased, the first cells that would be effected are A) cone cells. B) rod cells. C) lateral geniculate cells. D) ganglion cells. E) bipolar cells.

35) You are dissecting a species of amphibian that has just been discovered in the rainforest. You find a blood vessel where the blood travels at a low pressure and velocity. If the frog is in an upright position, blood flow through this vessel would also be against gravity. Anatomically, what do you expect of this blood vessel? A) A high degree of compliance B) A thick muscular wall C) Large wall to lumen ratio D) Valves that allow only one-way flow of blood E) All of the answers are correct

36) Which of the following statements regarding hearing is TRUE? A) The pitch of sounds is conveyed by the amplitude of the vibration of the oval window. B) Low-pitched tones selectively cause vibration of the basilar membrane at a point closer to the oval window than high-pitched tones do. C) Sound is amplified as it is conducted from the oval window to the tympanic membrane. D) The loudness of a sound is conveyed by the frequency of action potentials generated in the cochlear nerve.

37) The incus, malleus, and stapes of the middle ear A) serve to keep the pressure on the two sides of the tympanic membrane equal. B) are part of the vestibular apparatus. C) are in direct contact with both the tympanic membrane and the round window. D) serve to amplify the pressure of sound vibrations from the air in the outer ear to the fluid in the inner ear. E) are found inside the cochlear duct.

37) Which of the following statements regarding skeletal muscle is TRUE? A) Skeletal muscle fibers have pacemaker activity. B) Skeletal muscle fibers are joined together by gap junctions. C) A given skeletal muscle fiber will contract when excitatory nervous stimuli sufficiently exceed inhibitory nervous stimuli at the motor end plate. D) A given skeletal muscle fiber will contract if excitatory synaptic inputs sufficiently exceed inhibitory synaptic inputs on the motor neuron that innervates that fiber and the motor neuron fires an action potential. E) Skeletal muscle contraction is inhibited by inhibitory motor neurons that synapse onto skeletal muscle fibers.

38) Alpha EEG rhythm is descriptive of or occurs during A) slow-wave sleep. B) paradoxical sleep. C) both slow-wave sleep and paradoxical sleep. D) neither slow-wave sleep nor paradoxical sleep.

39) Which of the following statements concerning control of blood flow through arterioles is TRUE? A) Beta-adrenergic receptors are more abundant on most arteriolar smooth muscle than are alpha-adrenergic receptors. B) Binding of epinephrine to alpha-adrenergic receptors causes vasodilation. C) Increased stimulation of vascular smooth muscle by the parasympathetic nervous system causes increased vasoconstriction. D) If the arterial blood pressure to an organ suddenly decreases, arterioles in the organ will dilate in response. E) Body-wide constriction of arterioles results in a decrease in the total peripheral resistance (TPR).

42) If a biopsy of the quadriceps muscles (muscles on the front of the thigh) were taken from gold medal-winning speed skaters in the four following events, which would most likely have the SMALLEST percentage of type 1 muscle fibers? A) 10,000 meters B) 5,000 meters C) 1,000 meters D) 500 meters

42) Normally, the hydrostatic pressure difference between capillary fluid and interstitial fluid favors movement of fluid ________ a tissue capillary. The protein osmotic pressure difference between capillary fluid and interstitial fluid normally favors movement of fluid ________ a tissue capillary. A) into; into B) into; out of C) out of; out of D) out of; into

45) Which of the following are classified as "mechanoreceptors"? A) Cone cells in the eye B) Taste buds on the tongue C) Hair cells in the olfactory mucosa D) Hair cells in the cochlea

46) Which is a TRUE statement about excitation-contraction coupling? A) In skeletal muscle cells, it requires the influx of extracellular calcium ion. B) In smooth muscle cells, it must be preceded by an action potential in the cell membrane. C) In all kinds of muscle it requires the entry of calcium from the extracellular fluid. D) Calcium-induced calcium release plays a role in cardiac muscle cells, as well as in some smooth muscle cells. E) In skeletal muscle cells, excitation-contraction coupling begins when an action potential propagates along the sarcoplasmic reticulum membrane.

47) Which of the following statements regarding contraction in skeletal and smooth muscle is TRUE? A) In skeletal muscle, calcium initiates contraction by binding to troponin, while in smooth muscle calcium initiates contraction by binding directly to myosin. B) In skeletal muscle, calcium ions bind to a regulatory protein on thin filaments; in smooth muscle, calcium ions bind to a regulatory protein on thick filaments. C) In skeletal muscle, calcium initiates contraction by binding to myosin light-chain kinase, while in smooth muscle calcium initiates contraction by binding directly to tropomyosin. D) In skeletal muscle, calcium initiates contraction by binding to troponin, while in smooth muscle calcium initiates contraction by binding to calmodulin. E) All of the choices are true.

48) Which of the following correctly pairs a chemical with its associated taste modality? A) Poisonous alkaloids, sour B) Acids, bitter C) Sugars, salty D) Glutamate, umami E) Lipids, sweet

5) A male patient complains of physical weakness and fatigue. A blood test shows his hematocrit to be 30%. Which of the following diagnoses is the least likely to explain his symptoms? A) Internal bleeding B) Dietary iron deficiency C) Dietary vitamin B12 deficiency D) Lung disease E) Kidney disease

5) Which best describes the process of "adaptation" in sensory receptors? A) Information from sensory receptors reaches the cerebral cortex and the person becomes aware of it B) Conversion of the energy of a stimulus into a pattern of electrical activity C) Persistence of the sensation of a limb even after it has been severed from the body D) A decrease in receptor sensitivity despite continuation of a stimulus E) A depolarization of receptive membrane that increase in magnitude as the stimulus intensity increases

52) Cone cells belong to what category of sensory receptors? A) Mechanoreceptors B) Chemoreceptors C) Nociceptors D) Photoreceptors E) Proprioceptors

55) Which of the following factors would NOT tend to increase systemic arterial blood pressure? A) Increased sympathetic stimulation B) Increased blood volume C) Increased venous return D) Increased parasympathetic stimulation E) Increased activity of the skeletal muscle pump

58) Jane donates a pint of blood to a blood bank. A few minutes later, which of the following would be decreased compared to pre-donation values? A) Her stroke volume and total peripheral resistance B) Her heart rate and total peripheral resistance C) Her heart rate and mean arterial pressure D) The percentage of her cardiac output flowing to her kidneys E) Blood flow to her brain

6) Where is most of the iron in a person's body located? A) In the bone marrow B) In the liver C) In the cytochromes D) In erythrocytes E) In the kidneys

60) Following hemorrhage, reflexes are triggered that attempt to compensate for the blood loss. As a result of the blood loss and the reflex mechanisms, which of the following will be TRUE, compared to pre-hemorrhage values? A) Both cardiac output and total peripheral resistance will be increased. B) Both cardiac output and total peripheral resistance will be decreased. C) Cardiac output will be increased and total peripheral resistance will be decreased. D) Cardiac output will be decreased and total peripheral resistance will be increased. E) Hematocrit will be increased.

75) Platelets participate in hemostasis by A) aggregating to form a plug and manufacturing fibrinogen. B) secreting nitric oxide and releasing chemicals that promote vasoconstriction. C) secreting prostacyclin, which prevents platelet aggregation on blood vessel endothelium. D) aggregating to form a plug and releasing chemicals that promote vasoconstriction. E) secreting tissue plasminogen activator (t-PA) whenever they come into contact with collagen.

9) Rigor mortis is caused by A) buildup of lactic acid. B) lack of Ca2+. C) depletion of glycogen. D) lack of ATP. E) deficient acetylcholine receptors.

A chemical precursor for cortisol is ________, which is made from ________. Cortisol is secreted by ________ when stimulated by ________ from the anterior pituitary. A) androstenedione; progesterone; adrenal cortex; corticotropin-releasing hormone (CRH) B) progesterone; cholesterol; adrenal medulla; adrenocorticotropic hormone (ACTH) C) testosterone; cholesterol; adrenal medulla; adrenocorticotropic hormone (ACTH) D) progesterone; cholesterol; adrenal cortex; adrenocorticotropic hormone (ACTH) E) estradiol; cholesterol; adrenal medulla; corticotropin-releasing hormone (CRH)

A man with hypertension takes a diuretic that is not potassium-sparing, and he does not increase his ingestion of potassium. Which of the following side-effects would the drug be most likely to cause? A) Increased blood volume B) Depolarized neuronal cell membranes C) Hyperkalemia D) Cardiac arrhythmia E) All of these side effects would occur.

Action potentials in neurons in the inspiratory center of the medulla oblongata result in action potentials in the ________ nerves to the diaphragm, which in turn cause ________ of the muscle, resulting in a/an ________ in the volume of the thoracic cage. A) motor; contraction; decrease B) parasympathetic; contraction; decrease C) sympathetic; contraction; increase D) motor; contraction; increase E) sympathetic; relaxation; increase

After CO2 is produced by tissues, in what form is most of that carbon transported to the lungs for removal from the body? A) As dissolved CO2 B) Bound to hemoglobin C) As H2CO3 D) As dissolved HCO3- E) As carbonic anhydrase

Baby Sylvia is born with a thyroid deficiency. Which of the following can we expect for Sylvia if it goes untreated? A) Gigantism B) Acromegaly C) Growth rate will be faster than normal. D) Growth rate will be slower than normal. E) Body temperature will be above normal.

Following a series of high-intensity training runs, lactic acid was generated by the leg muscles and is now circulating in the blood. Which of the following is likely to occur? A) Decreased renal secretion of hydrogen ion B) Decreased renal reabsorption of bicarbonate ion C) Increased plasma PCO2 D) Decreased urinary pH E) Decreased urinary ammonium

How is the concentration of a hormone in plasma determined? A) Only by its rate of secretion B) By the number of its target cells in the body C) Only by its rate of synthesis D) By its secretion and clearance rates, and whether or not it binds to carriers and/or other plasma proteins E) Only by the rate of its degradation by the liver and kidneys

If all other factors remain the same, which of these results in an increase in the amount of oxygen bound to hemoglobin? A) Increased plasma [H+] B) Increased plasma temperature C) Increased plasma [2,3 diphosphoglycerate] D) Increased plasma PO2 E) Increased plasma [carbon monoxide]

In what form is the body's largest pool of calcium? A) Embedded in collagen in many types of connective tissue B) Blood, dissolved within the plasma C) Skeletal muscle, stored in terminal cisternae D) Bones, in the form of hydroxyapatites E) Liver, inside the endoplasmic reticulum

Regarding the relationships between the rates of oxygen consumption/carbon dioxide production and alveolar ventilation, which of these statements is TRUE? A) Increased ventilation without a similar increase in metabolism is called hypoventilation. B) In hypoventilation, alveolar PCO2 decreases below resting levels. C) In hyperventilation, alveolar PCO2 can decrease to zero. D) A decrease in metabolism without a similar decrease in alveolar ventilation would result in hyperventilation. E) An increase in ventilation with a matching increase in metabolism is called hyperventilation.

The amount of a substance that is excreted in the urine is equal to the amount that is ________ plus the amount that is ________ minus the amount that is ________. A) filtered; reabsorbed; secreted B) reabsorbed; filtered; secreted C) secreted; reabsorbed; filtered D) filtered; secreted; reabsorbed E) reabsorbed; secreted; filtered

Under what condition is lung compliance increased? A) Respiratory distress syndrome of the newborn B) Prolonged shallow breathing C) Cystic fibrosis D) Emphysema E) Asthma

What is a main difference between the modes of action of peptide hormones and steroid hormones? A) Peptide hormones bind to intracellular receptors, whereas steroid hormones bind to receptors on the cell surface. B) Peptide hormones act as second messengers, whereas steroid hormones bind to receptors in the cytosol. C) Peptide hormones bind to receptors on the cell surface, whereas steroid hormones act as second messengers. D) Peptide hormones bind to receptors on the cell surface, whereas steroid hormones bind to intracellular receptors. E) There are no differences; both act by binding to intracellular receptors.

10) You have designed a drug that is supposed to bind to the myosin binding sites on actin. You inject it into a relaxed muscle, but find that none of the drug bound. Which of the following explains why? A) There are no myosin binding sites on actin. B) Troponin molecules are covering myosin binding sites on actin. C) The myosin binding sites are covered by ATP. D) The myosin binding sites on actin are covered by tropomyosin. E) None of the choices are correct.

24) During the cardiac cycle of an individual at rest A) the volume of blood leaving the left side of the heart is greater than that leaving the right side. B) the pressure of blood leaving the right ventricle is greater than that leaving the left ventricle. C) the duration of systole is greater than that of diastole. D) the duration of diastole is greater than that of systole. E) the contraction of the atria overlaps in time with the ventricular systole.

24) Selective attention is facilitated, enhanced, and improved by way of the ________ of the brainstem, which acts as the origin point of neurons, which project to the cerebral cortex and release ________ neurotransmitter(s). A) pons, acetylcholine B) basal nuclei, dopamine C) hypothalamus, serotonin D) locus ceruleus, norepinephrine E) thalamus, melatonin

25) Which of the following statements regarding skeletal muscle contraction is true? A) During a lengthening contraction, the tension exerted by the muscle exceeds the load on the muscle. B) In every isotonic muscle contraction, the length of the muscle remains constant. C) During every muscle contraction, muscle fibers change length. D) During every muscle contraction, tension is developed in the muscle. E) Cross-bridges cycle faster during isometric contractions than during isotonic contractions.

25) Which of the following statements with regard to vision is FALSE? A) Photoreceptors are neurons. B) There are two basic types of photoreceptors in the retina, rods, and cones. C) There are normally four different photopigments in the retina. D) There are four different chromophore molecules in the retina. E) There are four different opsins in the retina.

27) Anterograde amnesia is associated with damage to all of the following structures of the brain, EXCEPT the A) thalamus. B) hypothalamus. C) limbic system. D) corpus callosum. E) hippocampus.

30) In ________ cells, invaginations of the external plasma membrane and proteins found there allow us to detect different colors of light. A) bipolar B) rod C) ganglion D) cone E) pigment epithelial

33) According to the Frank-Starling mechanism of the heart A) the left ventricle ejects a larger volume of blood with each systole than the right ventricle. B) the intrinsic rate of the heart's pacemaker is 100 beats/min. C) cardiac output increases with increased heart rate. D) stroke volume increases with increased venous return. E) both ventricles contract simultaneously.

33) Conceptual aphasia is a result of damage to A) the mouth and vocal cords. B) the cerebellum. C) Broca's area. D) Wernicke's area. E) the primary visual cortex.

Tom is on a health kick and wants to make sure that he is always in balance in terms of total body water. Which of the following is important for him to keep in mind? A) He must ingest more water than is lost in the urine. B) He must ingest more water than is lost by all output pathways combined. C) He must ingest less water than is lost in the urine. D) The water filtered into Bowman's capsule must be 100% reabsorbed. E) The amount ingested plus that metabolically produced must equal the amount of water in the urine.

Tracey has been experiencing a fever and a feeling that she needs to urinate every few minutes, even though she has a very low urine volume. She goes to her doctor who tells her that she has a bacterial infection of her bladder. An ultrasound of her ureters indicates that there is no infection in the ureters. Where did the infection begin? A) Her urethra B) Her nephrons C) Her renal arteries D) Her renal pelvis E) None of these sites

Type II alveolar cells are among the last cells to mature during fetal development. In babies born prematurely, type II alveolar cells are often not ready to perform their function. Which of the following would be TRUE of these babies? A) They would be at risk of alveolar collapse due to too much surface tension in the alveoli. B) They would be at risk of bacterial infections in the lungs. C) They would be at risk of autoimmune diseases with lung complications. D) They would be more likely to have coughing fits. E) None of these would occur.

Type II alveolar cells are among the last cells to mature during fetal development. In babies born prematurely, type II alveolar cells are often not ready to perform their functions. Which of the following drugs would be most likely to help an infant with immature type II alveolar cells? A) Pulmonary surfactant B) A beta-adrenergic agonist C) A muscarinic agonist D) Histamine E) A beta-adrenergic antagonist

Under normal circumstances, which of the following would result from an increase in transpulmonary pressure? A) Inhalation/inspiration B) Exhalation/expiration C) A collapsed lung D) Pneumothorax E) Emphysema

Water and NaCl reabsorbed from the loop of Henle directly reenter which blood vessels? A) Vasa recta B) Afferent arterioles C) Efferent arterioles D) Cortical peritubular capillaries E) Collecting ducts

What is one function of the type II alveolar cells? A) Production of surfactant B) Secretion of mucus C) Phagocytizing bacteria and other foreign particles D) Make up the majority of the epithelial wall of the alveoli E) Lining the pleural space

What is the primary regulator of the magnitude of alveolar ventilation under normal circumstances? A) The H+ concentration in the brain extracellular fluid, which is monitored by central chemoreceptors B) The PO2 of the arterial blood, which is monitored by central chemoreceptors C) The PO2 of the arterial blood, which is monitored by peripheral chemoreceptors D) The H+ concentration in the arterial blood, which is monitored by central chemoreceptors E) Stretch receptors in the lung

When blood Ca2+ levels fall below normal, in what ways do the kidneys help restore them toward normal? A) By increasing 1,25-dihydroxyvitamin D3 formation, decreasing tubular phosphate reabsorption, and increasing tubular Ca2+ reabsorption B) By increasing 1,25-dihydroxyvitamin D3 formation, increasing tubular phosphate reabsorption, and increasing tubular Ca2+ reabsorption C) By decreasing 1,25-dihydroxyvitamin D3 formation, increasing tubular phosphate reabsorption, and increasing tubular Ca2+ reabsorption D) Increasing 1,25-dihydroxyvitamin D3 formation and increasing secretion of parathyroid hormone E) By increasing renal secretion of parathyroid hormone and increasing bone resorption

When examining an endocrine cell from a new species of mammal under the microscope you find that it contains an abundance of rough endoplasmic reticulum, a large Golgi apparatus, and secretory granules. Which of the following is most likely to be true about these cells? A) It secretes a peptide/protein hormone. B) It secretes its product by diffusion through the lipid bilayer of the plasma membrane. C) It secretes by endocytosis. D) Its hormone product is synthesized from cholesterol. E) It secretes a hormone with a hydrophobic structure.

Which correctly describes renin? A) It is secreted by juxtaglomerular cells in renal afferent arterioles. B) Its secretion is enhanced by high levels of Na+ in the macula densa. C) Its secretion is stimulated by elevated blood pressure in the renal afferent arterioles. D) It acts on the adrenal cortex to stimulate aldosterone secretion. E) It is secreted by the liver in response to low blood pressure.

98) Of which categories of receptor types are nociceptors? A) Mechanoreceptors B) Proprioceptors C) Chemoreceptors D) Photoreceptors E) None of these

A, C

11) In a laboratory experiment you have treated a muscle cell with a calcium channel blocker. The membrane still depolarizes, but the concentration of calcium never increases in the cytosol. Which of the following describes what will happen next? A) Only one cross-bridge cycle will occur but no second cycle. B) Binding of myosin to actin will take place. C) Tropomyosin will continue to cover the myosin binding sites on actin and no cross-bridges will form. D) A single twitch in skeletal muscle but no sustained contraction. E) Contraction will occur, but the muscle will be stuck in the contracted state and unable to relax.

13) Which of the following statements concerning the differences between action potentials in skeletal muscle cells and in ventricular cardiac muscle cells is TRUE? A) Like skeletal muscle cells, ventricular cardiac muscle cells have a resting membrane potential closer to the sodium equilibrium potential than to the potassium equilibrium potential. B) Unlike skeletal muscle cells, the initial depolarization of ventricular cells is mainly due to calcium influx, not sodium influx. C) After sodium influx through voltage-gated channels occurs in ventricular cells, prolonged influx of calcium from the extracellular fluid occurs. No such calcium influx occurs in skeletal muscle cells. D) Action potentials in skeletal muscle cells are longer in duration than action potentials in cardiac muscle cells. E) The efflux of K+ repolarizes skeletal muscle cells after an action potential, while repolarization in cardiac muscle cells is due to the efflux of Ca2+.

14) What is the function of the transverse tubules in a skeletal muscle fiber? A) They store the calcium ions that are the main source of activation for the cross-bridge cycle. B) They form the Z lines that mark the end of each sarcomere. C) They allow action potentials to propagate deep into the center of skeletal muscle cells. D) They manufacture and store ATP. E) They run in parallel with the myofibrils, and have abundant Ca2+-ATPase proteins for pumping Ca2+ back into the sarcoplasmic reticulum.

14) You are a synthetic chemist and have created a compound that appears to bind to acetylcholine receptors. When applied to the inside of the right atrium, what will the affect be? A) Increased force of atrial contraction B) Decreased force of atrial contraction C) Decreased heart rate D) Increased heart rate E) No effects on heart function

15) A build-up of K+ in the T-tubules can occur during periods of frequent muscle cell potentials. What will be the result? A) Inhibition of neurotransmitter release from the motor neuron B) Inhibition of muscle cell depolarization and contraction C) Inhibition of relaxation, muscle stays in contracted state D) None of the answer choices are correct

15) The plateau of the action potential in cardiac ventricular cells results from the opening of voltage-gated long-lasting ________ channels in the plasma membrane of the cell. A) Na+ B) K+ C) Ca2+ D) Cl- E) glucose

16) Which of the following would NOT be categorized as a "somatic" sensation? A) Pressure B) Cold and warmth C) Sound D) Proprioception E) Kinesthesia

17) You are counseling a pair of tired parents. All three of their children have been waking in the night frequently for the past few months. You ask them several questions about their parenting habits, which of the following might be the problem? A) Their kids are growing. B) Their kids are talking too much before bed and becoming excited. C) Their kids are going to bed hungry. D) Their nighttime baths are too hot, elevating their body temperatures. E) Their kids are genetically predisposed to nightwaking.

17) You are learning to read electrocardiograms. You know that the patient you are examining has a pathology affecting the depolarization of his ventricles, therefore you're looking for a change in what portion of his EKG? A) The P wave B) The T wave C) The QRS complex D) "The P wave" or "The T wave" but not "The QRS complex". E) None of these would be altered

19) A scientist labels ACh with fluorescent dye to be able to visualize under the microscope where ACh travels and binds. She takes an image of the motor end plate and see that ACh is A) bound to muscarinic receptors at the end plate. B) inside the muscle cell sarcoplasm. C) bound to acetylcholinesterase in the end plate membrane. D) bound to receptors on the sarcoplasmic reticulum. E) bound to Ca2+ ions.

12) Which is correct about the contraction sequence of the heart? A) The contraction and relaxation of all four chambers happen at the same time. B) The right atrium and ventricle contract at the same time, and as they are relaxing, the left atrium and left ventricle begin to contract. C) Contraction begins in the order: right atrium, then right ventricle, then left atrium, then left ventricle. D) The two atria contract at the same time, and as they are relaxing, the two ventricles contract together. E) The atria and ventricles begin their contractions at the exact same time, but the atrial contraction only lasts half as long as the ventricle contraction.

12) Which of the following statements regarding the determination of stimulus intensity is true? A) Stronger intensity stimuli cause rapid adaptation, while weaker stimuli cause slower adaptation. B) The amplitude of action potentials increases with increasing stimulus intensity. C) The duration of receptor potentials decreases with increasing stimulus intensity. D) The frequency of action potentials increases with increasing stimulus intensity. E) The only means of detecting intensity changes is through recruitment of greater numbers of sensory units.

13) With an implanted electrode you are able to cause an individual motor neuron that connects to the bicep muscle to fire an action potential. Which of the following is the most likely result? A) The entire bicep muscle contracts. B) A single muscle cell within the bicep muscle contracts. C) Between 10-1,000 muscle cells within the bicep muscle contract. D) It is impossible to predict based on this information alone.

15) X, Y, and Z are adjacent sensory receptors in the skin. During administration of the flu shot, a needle is inserted in the middle of Y's receptive field. All three receptors are activated. Which of the following is likely to be true? A) The receptor potential in neurons X and Z will be more depolarized than in neuron Y. B) It won't be possible to discriminate which neuron's receptive field was stimulated at its center. C) The frequency of action potentials in the afferent pathway from neuron Y will be increased by excitatory interneurons projecting from the afferent pathways from neurons X and Z. D) The frequency of action potentials in neuron Y will be greater than that in neurons X and Z. E) The receptor potentials in all three neurons will achieve the same, average value.

16) Regarding schizophrenia, A) people with schizophrenia frequently have disorders of sensory awareness. B) treatment of schizophrenia may result in symptoms of Parkinson's disease. C) lithium carbonate is the most common drug prescribed for schizophrenia. D) both "people with schizophrenia frequently have disorders of sensory awareness" and "treatment of schizophrenia may result in symptoms of Parkinson's disease" are correct. E) both "treatment of schizophrenia may result in symptoms of Parkinson's disease" and "lithium carbonate is the most common drug prescribed for schizophrenia" are correct.

17) As a muscle gets stronger the diameter of its individual muscle cells becomes larger. Which of the following structures ensures that the membrane potential change is translated into the depth of the cell? A) Z lines B) Sarcoplasmic reticulum C) H zone D) Transverse tubules E) Pores in the plasma membrane

18) Which of the following would be most likely to be determined with a patient's ECG recording? A) A heart murmur B) Stroke volume C) Cardiac output D) Blockage of conduction of electrical signals between the atria and the ventricles E) A leaky atrioventricular valve

20) Psychoactive drugs A) can be taken to relieve altered states of consciousness. B) can be taken to experience altered states of consciousness. C) may stimulate neuronal activity in the "reward" areas of the brain. D) All of the choices are correct.

20) The chemical curare is a nicotinic receptor antagonist. How will curare affect skeletal muscle function? A) It activates an autoimmune disease that destroys myelin. B) It will cause persistent twitches with short periods of rest in between. C) It will cause spastic paralysis (sustained, unwanted muscle contraction). D) It will cause flaccid paralysis (no muscle contraction possible). E) Muscle function is fine, but it will cause a loss of voluntary control.

21) Which of the following best explains how the phenomenon of "tolerance" develops with use of psychoactive drugs over time? A) Psychoactive drugs can alter blood flow to the brain. B) Psychoactive drugs often produce euphoria. C) Psychoactive drugs can cross the blood-brain barrier. D) Psychoactive drugs can inhibit production of endogenous neurotransmitters. E) Psychoactive drugs can up-regulate receptors for endogenous neurotransmitters.

22) Which of the following molecules might be used to relieve the symptoms of opiate withdrawal when opiate use is stopped? A) A drug that causes lower-than-normal secretion of neurotransmitter B) A drug that elevates mood C) A drug that acts as an antagonist to the same receptor as the original drug D) A drug that acts as an agonist of the opioid receptor E) All of the choices are correct

10. Which is TRUE about typical, resting neurons? A. The plasma membrane is most permeable to sodium ions. B. The concentration of sodium ion is greater inside the cell than outside. C. The permeability of the plasma membrane to potassium ions is much greater than its permeability to sodium ions. D. The plasma membrane is completely impermeable to sodium ions. E. The plasma membrane is completely impermeable to potassium ions.

10. The organelles that digest engulfed bacteria and cell debris are the: A. peroxisomes. B. endosomes. C. lysosomes. D. ribosomes. E. mitochondria.

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