Comp Phys Exam 2

Put the steps in neuromuscular junction synaptic transmission and EC-coupling (excitation-contraction coupling) in chronological order.

9. Motoneuron axon terminal are depolarized. 6. Vesicles containing acetylcholine fuse with axon terminal membrane. 11. Acetylcholine receptors open and conduct ions. 2. An EPSP is generated in the muscle cell. 4. Voltage-gated Na+ channels open in sarcolemma. 3. An action potential is conducted along the sarcolemma. 10. RyRs open. 5. Ca2+ rises in the muscle cell cytoplasm. 5. Ca2+ rises in the muscle cell cytoplasm. 12. Ca2+ binds to troponin C. 7. Tropomyosin rotates into groove of thin filament. 1. Myosin heads hydrolyze ATP during the cross-bridge cycle. 8. Ca2+ dissociates from troponin.

Which hormone has the longest half-life (clue: consider their chemical properties, role and how they are transported in the blood)? a. Estrogen b. Epinephrine c. Insulin d. Vasopressin

A. Estrogen

Describe two mechanisms by which the human nervous system can voluntarily alter the force and velocity of a contraction of the biceps muscle of the arm.

1. Varying numbers of motor units can be recruited. 2. Varying action potential frequency can generate twitches, unfused tetani, or fused tetanic contractions.

Explain why a muscle always works by shortening and cannot actively increase its length unless an external force pulls on it.

During the cross-bridge cycle, myosin goes through a characteristic sequence of conformational changes and interactions with actin. The power-stroke of the myosin head can only pull the actin-containing thin filament in one direction, so the muscle always works by shortening. However, external forces from other muscles or loads external to the body can act on the muscle to lengthen it.

Compare and contrast the synthesis, storage, and release of a peptide hormone such as growth hormone (GH) to those processes in a steroid hormone such as cortisol.

Peptide hormones such as growth hormone (GH) are synthesized at ribosomes, stored in vesicles, and secreted on demand. Steroid hormones, by contrast, are synthesized on demand prior to secretion and are released into the blood via diffusion.

During a long period between meals, there is a rise in the blood concentration of a. insulin. b. epinephrine. c. glucagon. d. glycogen.

c. glucagon.

What process(es) is(are) occurring in the figure? a. Diffusion b. Convection c. Active transport d. Both diffusion and convection

d. Both diffusion and convection

Which plot line on the graph likely represents an insulin-only treatment? a. I b. II c. III d. IV

d. IV

Running mice are capable of moving their legs back and forth much more quickly than elephants. Thus, compared to an elephant muscle cell, a mouse muscle cell likely contains more a. actin. b. myosin. c. troponin C. d. SR Ca2+-ATPase.

d. SR Ca2+-ATPase.

Describe the effect of adding acetylcholine to the area indicated by arrow IV in the figure. a. Acceleration of heart rate b. Complete stopping of the heart c. Deceleration of heart rate d. There is no effect

d. There is no effect

Describe the effect of adding acetylcholine to the area indicated by arrow V in the figure. a. Acceleration of heart rate b. Deceleration of heart rate c. Complete stopping of the heart d. There is no effect

Deceleration of the heart rate

What is the physiological importance of the hypothalamo-hypophysial portal system?

The hypothalamo-hypophyseal portal system is a specific pathway of vessels that connects the anterior pituitary to the hypothalamus. The axons of neurosecretory cells in the hypothalamus terminate in the neurohemal organ of the median emminence and the portal system transports the specific releasing or inhibiting hormones to the anterior pituitary but not into the general circulation.

Which animal group tends to have the thinnest gas-exchange membrane? a. Birds b. Mammals c. Nonavian reptiles d. Amphibians

a. Birds

Which statement regarding gas diffusion is true? a. Gases diffuse only slightly faster through the gas phase than through aqueous solutions. b. Gases diffuse many times faster through the gas phase than through aqueous solutions. c. Gases diffuse at equal rates through the gas phase and aqueous solutions. d. Gases diffuse only slightly slower through the gas phase than through aqueous solutions.

b. Gases diffuse many times faster through the gas phase than through aqueous solutions.

Which hormones are released by the posterior pituitary gland? a. Vasopressin and antidiuretic hormone b. Vasopressin and oxytocin c. Thyrotropin and vasopressin d. Antidiuretic hormone and prolactin

b. Vasopressin and oxytocin

Which diagram represents a neuroendocrine secretory system? a. I b. II c. III d. IV

c. III

Order the mechanisms of ATP generation by highest to lowest yield per episode of use. a. Anaerobic glycolysis; creatine phosphate; aerobic catabolism b. Aerobic catabolism; creatine phosphate; anaerobic glycolysis c. Creatine phosphate; anaerobic glycolysis; aerobic catabolism d. Aerobic catabolism; anaerobic glycolysis; creatine phosphate

d. Aerobic catabolism; anaerobic glycolysis; creatine phosphate

In skeletal muscle cells, cytoplasmic Ca2+ is bound by a. actin. b. tropomyosin. c. myosin. d. troponin.

d. troponin.

Describe how the kidney acts to conserve water when it senses low blood pressure.

Juxtaglomerular cells in the kidney secrete renin when blood pressure is low. Renin catalyzes the reaction forming angiotensin I from angiotensinogen, which then forms angiotensin II with the help of ACE. Angiotensin II stimulates the constriction of systemic arterioles, promotes thirst, stimulates vasopressin secretion, and stimulates aldosterone secretion. All of these actions promote the conservation of water as well as the increase in blood

Some crabs have giant skeletal muscle fibers that are much larger in diameter than muscle fibers found in most other animals. What fiber type are these fibers likely to be and why?

The giant fibers must be fast glycolytic fibers (FG). Oxidative fibers rely on continuous diffusion of oxygen from outside the cell to the mitochondria in order to generate ATP, so they can work effectively only if the fiber diameter (i.e., the diffusion distance for oxygen) is relatively small. Glycolytic fibers can generate ATP using substrates contained within the cell. Metabolic byproducts can then diffuse out of the cell slowly before the muscle is used again.

Vertebrate skeletal muscle is characterized by thin-filament regulation of contraction while smooth muscle is characterized by thick-filament regulation. Explain the distinction between thin-filament and thick-filament regulation

Thick Filaments in the regulation of smooth muscle contraction is triggered by a calcium-dependent structural change allowing myosin and actin to interact. Thick filaments are myosin heavy and contain light chains (phosphorylation of myosin light chains is triggered by calcium). The head containg the active binding site and ATPase activity. Thin filaments are composed of G-actin in the helix and regulatory tropomyosin and troponin. When calcium binds with troponin, it permits actin and myosin to interact in order to generate force.Thin filament skeletal muscle contraction regulation occurs by actin assosiated protyeins modulating the access to the myosin binding actin domains and myosin ATPase inhibition. In skeletal muscle, actin and myosin are able to interact and generate force when calcium binds to troponin C, which is part of the thin filament. In smooth muscle, actin and myosin are able to interact when calcium triggers phosphorylation of myosin light chains by myosin light-chain kinase

If the total pressure was 0.1 atm, the percent of Argon in the gas mixture would be _______% a. 0.93 b. 0.093 c. 0.0093 d. 0.00093

a. 0.93

Which O2 partial pressure value would you expect to find in the ambient air (AA), arterial blood (AB), and systemic capillary blood (SCB) of an animal? a. AA = 150 mm Hg; AB = 100 mm Hg; SCB = 70 mm Hg b. AA = 150 mm Hg; AB = 70 mm Hg; SCB = 100 mm Hg c. AA = 70 mm Hg; AB = 100 mm Hg; SCB = 70 mm Hg d. AA = 70 mm Hg; AB = 100 mm Hg; SCB = 150 mm Hg

a. AA = 150 mm Hg; AB = 100 mm Hg; SCB = 70 mm Hg

Which statement regarding the feedback mechanisms of the HPA axis is true? a. Glucocorticoids inhibit the secretion of ACTH. b. Glucocorticoids enhance the secretion of CRH. c. ACTH enhances the secretion of CRH. d. ACTH decreases the secretion of glucocorticoids.

a. Glucocorticoids inhibit the secretion of ACTH.

Which hormone is direct acting? a. Prolactin (PRL) b. Thyroid-stimulating hormone (TSH) c. Adrenocorticotropic hormone (ACTH) d. Luteinizing hormone (LH)

a. Prolactin (PRL)

Which statement about skeletal muscle is true? a. Proteins in thick filaments pull on thin filaments, while intermediate filaments hold sarcomeres together. b. Proteins in thin filaments pull on thick filaments, while intermediate filaments hold sarcomeres together. c. Proteins in intermediate filaments pull on thin filaments, while thick filaments hold sarcomeres together. d. Proteins in thin filaments pull on intermediate filaments, while thick filaments hold sarcomeres together.

a. Proteins in thick filaments pull on thin filaments, while intermediate filaments hold sarcomeres together.

Muscles of the larynx that help mammals to produce complex sounds can contract and relax at much higher frequencies than the muscles of the limbs, but they produce relatively low force as they act on the vocal cords. Based on these characteristics, one may predict that laryngeal muscles have a. a high volume fraction of sarcoplasmic reticulum. b. troponin with high Ca2+ affinity. c. a high volume fraction of myofibrils

a. a high volume fraction of sarcoplasmic reticulum.

On the plateau of the length‒tension curve for whole skeletal muscles, a. all myosin heads are in proximity to actin. b. all actin monomers are in proximity to myosin heads. c. the distance between Z disc is minimal.

a. all myosin heads are in proximity to actin.

During the _______ developmental stage, the bullfrog splits oxygen uptake (roughly 50:50) between the gills and the skin. a. aquatic tadpole b. air-breathing tadpole c. postmetamorphic froglet d. adult

a. aquatic tadpole

In smooth muscle, calcium must bind to _______ to initiate contraction. a. calmodulin b. troponin c. myosin d. ryanodine receptor

a. calmodulin

Oxygen that is bound to hemoglobin a. does not contribute to the oxygen partial pressure. b. contributes the same amount to partial pressure as when it is dissolved in solution. c. contributes more to partial pressure than when it is dissolved in solution. d. increases the partial pressure of CO2.

a. does not contribute to the oxygen partial pressure.

Aldosterone _______ reabsorption of _______ so that more water is _______. a. increases; Na+; reabsorbed b. decreases; K+; excreted c. decreases; Na+; reabsorbed d. increases; K+; excreted

a. increases; Na+; reabsorbed

For contraction to occur in smooth muscle a. myosin light chains must be phosphorylated. b. myosin light-chain kinase must be phosphorylated. c. calcium must bind to troponin C. d. DHPR must interact physically with ryanodine receptor calcium channels

a. myosin light chains must be phosphorylated.

The force that a particular vertebrate skeletal muscle produces can be altered by a change in the a. number of motor units recruited. b. proportion of myofibrils activated per muscle fiber. c. amount of calcium released in response to each action potential. d. size of the action potentials in motor neurons.

a. number of motor units recruited.

Henry's law relates _______ in aqueous solutions. a. partial pressure and concentration b. partial pressure and volume c. pressure and volume d. temperature and concentration

a. partial pressure and concentration

A swimming white shark is doing ram ventilation. Assume that 100 L water is going into its mouth per min. Oxygen concentraion in the seawater is 5 mL /L and the water leaving its gill slits have a concentration of 3 mL/L. What is the rate of oxygen uptake in mL/min? a. 100 b. 200 c. 300 d. 500 e. It cannot be detemined based on the available data

b. 200

In the figure, how many arrows (including labeled and unlabeled) are in the vicinity of a possible EPSP? a. 3 b. 4 c. 5 d. 8

b. 4

Which of the following have the most similar O2 partial pressures? a. Ambient air and alveolar gas b. Alveolar gas and arterial blood c. Arterial blood and average systemic capillary blood d. Average systemic capillary blood and mitochondria

b. Alveolar gas and arterial blood

Which hormone acts to reduce plasma volume? a. Angiotensin II b. Atrial natriuretic peptide c. Aldosterone d. ADH (vasopressin)

b. Atrial natriuretic peptide

Which of the following is the effector in the startle response of the cockroach? a.Movement of filiform hair receptors b.Contraction of the hind leg muscle c.A train of action potentials produced by the leg motor neuron d.Action potentials in the giant interneuron

b. Contraction of the hind leg muscle

Which statement regarding the diffusion of materials between gas mixtures and aqueous solutions is false? a. Diffusion can be predicted by means of partial pressure measurements. b. Diffusion can be predicted by using concentrations. c. Respiratory gases can exist in the gas phase as well as dissolved in an aqueous solution. d. Each gas has a unique solubility in aqueous solution.

b. Diffusion can be predicted by using concentrations.

Which physiological reaction would occur in response to direct sympathetic activation? a. Muscle protein anabolism b. Release of glucose from the liver c. Decrease in ventilation d. Increase in digestive activity

b. Release of glucose from the liver

According to the figure, what was the most likely cause of the zeroing of oxygen partial pressure in the nest? a. The eggs grew rapidly and used up the available oxygen. b. The nest was flooded with water. c. An algal bloom rapidly used up the available oxygen. d. The eggs hatched and rapidly used up the available oxygen

b. The nest was flooded with water.

If the percentage of oxygen in air at sea level is 20.95%, what is the percentage of oxygen in air at the top of Mount Everest? a. Significantly higher than 20.95% b. The same—20.95% c. Significantly lower than 20.95% d. Negligible—close to 0%

b. The same—20.95%

Suppose that at a temperature of 0°C and pressure of 1 atm, all the O2 is removed from 10 L of dry atmospheric air, and the remaining gas is restored to the original temperature and pressure. The final volume will be a. 10 L b. about 7.9 L. c. about 5 L. d. about 2.1 L.

b. about 7.9 L.

In skeletal muscle, an incomplete tetanus would result from a. action potentials arriving at a rate fast enough for the intracellular Ca2+ levels to rise much higher than they would in a muscle twitch. b. action potentials arriving at a rate fast enough for sarcomeres to generate force while the elastic components of the muscle are still stretched. c. action potentials arriving so quickly that there is no fluctuation in intracellular Ca2+ levels. d. many, but not all, of the thin filaments being activated to permit cross-bridge formation.

b. action potentials arriving at a rate fast enough for sarcomeres to generate force while the elastic components of the muscle are still stretched.

Application of acetylcholine directly to the heart will..? a. cause the heart to stop. b. cause the heart to slow down. c. cause the heart to speed up. d. have no effect on the heart.

b. cause the heart to slow down

Mammalian cardiac muscle cells are stimulated to contract by a. hormonal signals that trigger Ca2+ release and myosin light-chain phosphorylation. b. electrical signals transmitted through gap junctions from other cardiac muscle cells. c. action potentials from excitatory autonomic neurons. d. ion channels that open in response to stretch of the cardiac muscle cell membranes.

b. electrical signals transmitted through gap junctions from other cardiac muscle cells.

Single-unit smooth muscle differs from multiunit smooth muscle in that multiunit smooth muscle a. is usually stretch-activated. b. has cells that function as independent units. c. is often spontaneously active d. contains gap junctions that link the cells as an electrical unit.

b. has cells that function as independent units.

Which hormone is directly responsible for milk let-down (ejection)? a. Luteinizing hormone (LH) b. Oxytocin c. Prolactin d. Follicle-stimulating hormone (FSH)

b. oxytocin

In Krog's diffusion equation for gases a. permeability is integrated into P1-P2. b. permeability is integrated into K. c. P1-P2 represents permeability. d. X represents permeability.

b. permeability is integrated into K.

If air at 0°C contains 210 mL O2 per L, how much O2 (at STP/L) does it contain if it is heated to 24°C? a. 210 mL O2 per L b. 420 mL O2 per L c. 192 mL O2 per L d. 105 mL O2 per L

c. 192 mL O2 per L

If a muscle contains 10,000 sarcomeres in a series (i.e., end-to-end along its length), each sarcomere is ~2.5 µm in length, and each sarcomere can shorten by 2.5 µm/s, how fast can the muscle shorten? a. 2.5 µm/s b. 2.5 mm/s c. 2.5 cm/s d. 2.5 m/s

c. 2.5 cm/s

Oxygen in exhaled air from a person on a treadmill is measured and is 150 mL oxygen per liter air. Assume the inhaled air is ordinary atmospheric air at sea level. What is the approximate oxygen extraction efficiency (aka oxygen utilization coefficient or oxygen extraction coefficient)? a. 5% b. 10% c. 25% d. 50% e. 75%

c. 25%

Which neurotransmitter is being released at arrow V? a. norepinephrine b. Glutamate c. Acetylcholine d. GABA

c. Acetylcholine

Which enzyme must be present for the direct production of angiotensin II? a. Renin b. Angiotensinogen c. Angiotensin-converting enzyme (ACE) d. Angiotensin I

c. Angiotensin-converting enzyme (ACE)

Which of the following cannot modulate force production in smooth muscle? a. Inhibition of myosin light-chain kinase b. Inhibition of myosin light-chain phosphatase c. Binding of Ca2+ to troponin d. Hormonal stimuli

c. Binding of Ca2+ to troponin

Which action is considered a parasympathetic effect? a.Stimulation of the secretion of epinephrine from the adrenal medulla b. Inhibition of digestion c. Constriction of lung airways d. Increased blood pressure

c. Constriction of lung airways

Which morphology allows for the most efficient gas exchange? a. Cross-current b. Concurrent c. Countercurrent d. Cocurrent

c. Countercurrent

Which statement about the figures contain most correct information? a. Only figure B contains a neurohemal organ. b. Figures A and B contain a neurohemal organ. c. Figures A and B contain a neurohemal organ, and figure B also contains a portal system. d. Figures A and B contain a neurohemal organ, and figure A also contains a portal system.

c. Figures A and B contain a neurohemal organ, and figure B also contains a portal system.

Which molecules are respiratory gases or chemical forms of respiratory gases? I) O2 II) O3 III) CO2 IV) HCO3- V) N2 a. I, II, and III b. I, II, III, and IV c. I, III, and IV d. I, III, and V

c. I, III, IV

Which of the following is not part of the mammalian stress response? a. Release of glucocorticoids b. Vasoconstriction of specific regions such as the skin c. Increased release of thyroid-stimulating hormone d. Increase in fat catabolism

c. Increased release of thyroid-stimulating hormone

Which hormone functions in skin darkening in amphibians and non-avian reptiles? a. Glucocorticoids b. Adrenocorticotropin c. Melanocyte stimulating hormones d. Thyroid hormones

c. Melanocyte stimulating hormones

An anatomically distinct site for the release of neurohormones is called a(n) a. adenohypophysis. b. paraventricular nucleus. c. neurohemal organ. d. anastomosis.

c. Neurophemal organ

Smooth muscle cells possess which component? a. Sarcomeres b. T-tubules c. Sarcoplasmic reticulum d. Multiple nuclei

c. Sarcoplasmic reticulum

The adrenal medulla are innervated by: a. Parasympathetic preganglionic neurons b. Parasympathetic postganglionic neurons c. Sympathetic preganglionic neurons d. Sympathetic postganglionic neurons e. a+c f. b+d

c. Sympathetic preganglionic neurons

Which compound normally bypasses second messenger systems and alters gene expression? a. Adrenal medullary hormones b. Melatonin c. Testosterone d. Vasopressin

c. Testosterone

In a vertebrate skeletal muscle cell, depolarization of the t-tubule membrane causes dihydropyridine receptors to a. open and conduct Ca2+ into the t-tubule. b. open and conduct Ca2+ into the sarcoplasmic reticulum. c. change conformation which changes its interaction with ryanodine receptors. d. bind dihydropyridines and change configuration

c. change conformation which changes its interaction with ryanodine receptors.

A skeletal muscle fiber with high myosin ATPase activity, a high rate of Ca2+ reuptake by the sarcoplasmic reticulum, and large number of mitochondria would be classified as a a. slow glycolytic fiber. b. slow oxidative fiber. c. fast oxidative glycolytic fiber. d. fast glycolytic fiber

c. fast oxidative glycolytic fiber

If all of the panels in the figure represent data from one treatment, this treatment was most likely a. fasting. b. fasting and ingestion of a high-carbohydrate meal. c. fasting and ingestion of a high-protein meal. d. fasting and ingestion of a high-fat meal.

c. fasting and ingestion of a high-protein meal.

During an isometric tetanic contraction, the sarcomeres generate a. no force (tension). b. force (tension) but cannot stretch the elastic component of the muscle. c. force (tension) and stretch the elastic component of the muscle, but they cannot move the load. d. force (tension) but do not transmit it to the elastic component of the muscle.

c. force (tension) and stretch the elastic component of the muscle, but they cannot move the load.

Injections of _______ would likely result in the highest blood glucose levels in a mammal when measured 1 hour postinjection. a. insulin, glucagon, and epinephrine b. insulin and glucagon c. glucagon and epinephrine d. insulin and epinephrine

c. glucagon and epinephrine

The partial pressure of any given gas a. cannot be calculated from the universal gas law. b. is dependent on any other gas present. c. is the individual pressure exerted by the gas in a gas mixture. d. is proportional to the size of the gas molecule.

c. is the individual pressure exerted by the gas in a gas mixture.

Arrow I in the diagram points to a. insulin. b. the P segment. c. proinsulin. d. preproinsulin.

c. proinsulin

The smallest unit of a skeletal muscle that shortens during a muscle contraction is the a. myosin molecule b. thin filament. c. sarcomere. d. myofibril

c. sarcomere.

In striated muscle, _______ before the sarcomere can generate force. a. Ca2+ must dissociate from troponin C b. Ca2+ must be pumped by the SR Ca2+-ATPase c. the SR calcium channel must open d. calcium must bind to tropomyosin

c. the SR calcium channel must open

In resting skeletal muscle, contraction does not occur because a. there is very little ATP in the cytoplasm. b. most of the ATP is bound to other molecules for storage. c. there is very little calcium in the cytoplasm. d. myosin is inactivated.

c. there is very little calcium in the cytoplasm.

One reason that fast glycolytic muscle fibers fatigue more rapidly than slow oxidative muscle fibers is that fast glycolytic fibers a. have a higher capacity for oxidative phosphorylation than slow oxidative fibers. b. contain lower amounts of ATP than slow oxidative fibers. c. use ATP more rapidly than slow oxidative fibers. d. have a lower capacity for glycolysis than slow oxidative fibers.

c. use ATP more rapidly than slow oxidative fibers.

If the total pressure was 2 atm, the partial pressure of CO2 would be _______ atm. a. 0.04 b. 0.08 c. 0.0004 d. 0.0008

d. 0.0008

If the total pressure was 0.5 atm, the partial pressure of O2 would be _______ atm. a. 20.95 b. 10.48 c. 0.2095 d. 0.1048

d. 1048

Which hormone is directly controlled by a hypothalamic releasing hormone? a. Epinephrine b. Vasopressin c. Cortisol d. ACTH

d. ACTH

Why is the latent period of an isotonic twitch different from that of an isometric twitch? a. The motoneuron sends a longer action potential if there is an isotonic load on the muscle. b. The motoneuron sends a longer action potential if there is an isometric load on the muscle. c. An isometric twitch does not begin until the muscle develops enough force to lift the load. d. An isotonic twitch does not begin until the muscle develops enough force to lift the load.

d. An isotonic twitch does not begin until the muscle develops enough force to lift the load.

Which statement best describes the mechanism of ADH (antidiuretic hormone aka vasopressin) in the kidney? a. Aquaporins are removed from the cells apical membranes in the collecting duct so that more water can be reabsorbed. b. Aquaporins are removed from the cells apical membranes in the collecting duct so that more water can be excreted. c. Aquaporins are added to the cells apical membranes in the collecting duct so that more water can be excreted. d. Aquaporins are added to the cells apical membranes in the collecting duct so that more water can be reabsorbed

d. Aquaporins are added to the cells apical membranes in the collecting duct so that more water can be reabsorbed

The labels in the figure correspond to which parts of the nervous system? a. I = sympathetic; II = parasympathetic; III = somatic b. I = somatic; II = sympathetic ; III = parasympathetic c. I = peripheral; II = autonomic; III = somatic d. I = somatic; II = parasympathetic; III = sympathetic

d. I = somatic; II = parasympathetic; III = sympathetic

A surprise meeting with a cougar (mountain lion) on your leisure walk would likely cause all the following physiological reactions except for: a.Inhibited digestive function b.Pupil dilation c.Increased glucose production d.Increased insulin secretion e.Inhibited salivation

d. Increased insulin secretion

The power stroke of the myosin head occurs in conjunction with what other event of the cross-bridge cycle? a. ATP hydrolysis to ADP and inorganic phosphate b. ATP binding to the myosin head c. Release of ADP from the myosin head d. Release of inorganic phosphate from the myosin head

d. Release of inorganic phosphate from the myosin head

Which best explains why fast glycolytic muscle fibers are larger than slow oxidative fibers? a. Fast glycolytic fibers are larger to exchange glucose across the sarcolemma more quickly. b. Fast glycolytic fibers are larger to generate larger action potentials and greater force. c. Slow oxidative fibers can oxidize a variety of fuels, whereas fast glycolytic fibers primarily oxidize glucose/glycogen. d. Slow oxidative fibers rely on the diffusion of oxygen via capillaries.

d. Slow oxidative fibers rely on the diffusion of oxygen via capillaries.

Which statement about slow oxidative and fast glycolytic muscle fibers is false? a. They have different numbers of organelles such as mitochondria and sarcoplasmic reticulum. b. They have different amounts of metabolic enzymes such as hexokinase or citrate synthase. c. They have different amounts of certain proteins, such as sarcoplasmic reticulum Ca2+-ATPase. d. Their thick and thin filaments are arranged differently.

d. Their thick and thin filaments are arranged differently.

How does a typical teleost fish, such as a goldfish, maintain ventilation of its gills when stationary in the water column? a. Via ram ventilation b. With a buccal pressure pump c. With an opercular suction pump d. With both a buccal pressure pump and an opercular suction pump.

d. With both a buccal pressure pump and an opercular suction pump

A blood sample that has an extremely low partial pressure of CO2 is most likely from a(n) a. marine animal. b. terrestrial animal. c. animal exchanging respiratory gas with air. d. animal exchanging respiratory gas with water.

d. animal exchanging respiratory gas with water.

In oxygen transport from the external air to the mitochondria, diffusion occurs from a. the mouth to the lungs. b. the lungs to the red blood cells. c. the red blood cells to the mitochondria. d. both the lungs to the red blood cells and the red blood cells to the mitochondria.

d. both the lungs to the red blood cells and the red blood cells to the mitochondria.

As a gas mixture or an aqueous solution flows, gas molecules in the gas or liquid are carried from place to place by a. tidal flow. b. diffusion. c. evaporation. d. convection

d. convection

Calcium enters the cytoplasm of a smooth muscle cell by a. active transport from the sarcoplasmic reticulum only. b. active transport from the extracellular space and the sarcoplasmic reticulum. c. diffusion from the sarcoplasmic reticulum only. d. diffusion from the extracellular space and the sarcoplasmic reticulum.

d. diffusion from the extracellular space and the sarcoplasmic reticulum.

During an eccentric muscle contraction, the a. length of the sarcomeres remains unchanged, but the length of the elastic component increases. b. sarcomeres shorten, but the length of the elastic component remains unchanged. c. muscle produces force and its length decreases. d. muscle produces force and its length increases.

d. muscle produces force and its length increases.

The _______ division has a long preganglionic neuron synapsed with a short postganglionic neuron. a. enteric b. sympathetic c. autonomic d. parasympathetic

d. parasympathetic

During high speed swimming, many fish rely on a method of ventilation called a. the opercular suction pump. b. buccal pressure pumping ventilation. c. opercular pumping ventilation. d. ram ventilation.

d. ram ventilation.

The rate of convective gas transport depends on the a. partial pressure of a particular gas in solution. b. rate of fluid flow. c. total concentration of gas in the fluid. d. rate of fluid flow and the total concentration of gas in the fluid.

d. rate of fluid flow and the total concentration of gas in the fluid.

Glucagon and epinephrine together amplify each other's effectiveness in opposing the actions of insulin on blood glucose. This amplification is an example of...? a. agonism. b. permissiveness. c. antagonism. d. synergism.

d. synergism

According to the sliding filament theory of muscle contraction, myosin heads pull on _______ filaments and a. thick; move the Z discs apart b. thick; move the Z discs together c. thin; move the Z discs apart d. thin; move the Z discs together

d. thin; move the Z discs together

The rate of O2 uptake by the breathing organ depends on the a. volume flow of air or water per unit of time. b. amount of O2 removed from each unit of volume. c. amount of CO2 needing to be removed. d. volume flow of respiratory medium per unit time and the amount of O2 removed from each unit volume.

d. volume flow of respiratory medium per unit time and the amount of O2 removed from each unit volume.