exsc 363

Compared to resting, during exercise the _____.

-PO2 gradient between arterial blood and skeletal muscle increases -PCO2 gradient between skeletal muscle and venous blood increases

Compared to resting, energy expenditure during exercise increases because _____.

-VO2 increases -the caloric equivalent increases

Each myosin head has a binding site for _____ (check all that apply).

-actin -ATP

How many neuromuscular junctions does each skeletal muscle fiber have?

1

When 1 g Hb is fully saturated, how much oxygen will it carry?

1.34 mL

From the beta oxidation of a 20-carbon fatty acid, how many acetylCoA molecules enter the Krebs Cycle?

10

Which of the following represents a normal av-O2 difference during moderate to high intensity aerobic exercise?

15 mL/dL

Following exercise, one should consume _____.

16-24 fl. oz. of water per pound of weight lost during exercise

How many acetyl CoA enter the Krebs Cycle from one glucose during aerobic glycolysis?

2

How many pyruvates are produced from glycolysis of one glucose?

2

The acetyl group that enters the Krebs Cycle is a _____.

2 carbon molecule

After starting aerobic exercise at an intensity that is below the lactate threshold, a steady-state VO2 is normally achieved in about _____.

3 minutes

During the recovery period following exercise, the complete replenishment of CrP takes _____.

3-5 minutes

How many net ATP are resynthesized from glucose in aerobic glycolysis?

36

Susan is comparing her urine color to a urine color chart. What color on the urine color chart would indicate dehydratation?

4 and above

Which of the following represents a normal av-O2 difference at rest?

4 mL/dL

Which of the following is a reasonable EF during high intensity aerobic exercise?

80%

During exercise, which of the following would most rapidly increase the activity of rate limiting enzymes?

A decrease in ATP and an increase in ADP and Pi.

Which of the following motor neurons would conduct an action potential the slowest?

A small unmyelinated neuron

Compared to resting conditions, which of the following is necessary to increase blood flow to active skeletal muscle during exercise?

A. An increase in total blood flow (i.e., cardiac output). B. A decrease in venous pooling and an increase in venous return to the heart. C. The prioritization and redistribution of blood flow away from less metabolically active tissue to the more metabolically active skeletal muscle mass. D. All of the above.

Which of the following occurs in the liver?

A. Glycogenesis B. Glycogenolysis C. Gluconeogenesis D. All of the above

Compared to resting, during exercise, a greater binding of NE/EPI to beta-1 receptors will result in an increase in _____. (check all that apply)

A. HR B. SV C. Q D. SBP

Which of the following is a true statement about lactate?

A. Most of the lactate produced in a muscle cell at rest is oxidized in the same muscle cell. B. Lactate produced in a muscle cell can be transported out of the muscle cell and oxidized elsewhere. C. The amount of lactate oxidized in the heart during exercise significantly contributes to the energy needs of the heart. D. Type II fibers tend to be high producers of lactate and type I fibers tend to be high consumers of lactate. E. All of the above.

Which of the following types of muscle have the property of conductivity?

A. Smooth muscle B. Cardiac muscle

Muscle fatigue during a single bout of high intensity (>85% VO2max) aerobic exercise is most likely related to _____.

A. a decrease in pH B. an increase in inorganic phosphate

As duration of aerobic exercise increases, the increased use of fatty acids as an energy substrate can be attributed to _____.

A. an increase in NE and EPI that stimulates lipolysis in adipose tissue B. a decrease in insulin, which stimulates lipolysis C. an increase in glucagon which stimulates lipolysis in adipose tissue D. All of the above

Compared to resting, the increase in HR during exercise is a result of _____.

A. an increase in sympathetic tone B. a decrease in parasympathetic tone

Compared to resting, during exercise, venous return increase because of _____ (check all that apply).

A. an increase in ventilation (frequency and depth of breathing) B. contraction of skeletal muscle C. an increase in HR and force of contraction of the heart D. vasoconstriction of veins

You work as an exercise specialist in a clinic that provides exercise interventions for the aging segment of the population. You notice that compared to even a middle-aged person, older individuals have less muscle strength. This is due to _____.

A. atrophy and loss of muscle mass B. the degeneration of somatic motor neurons C. a decrease in the number of motor units D. all of the above

During the contraction of skeletal muscle, ATP is used _____.

A. during the power stroke of the myosin heads B. to release the myosin head from the actin filament C. to pump calcium into and out of the sarcoplasmic reticulum D. to drive the sodium-potassium pump E. for all of the above

Parasympathetic stimulation of the heart has a _____.

A. negative chronotropic effect B. negative dromotropic effect

Decrements in performance due to dehydration are related to the impact of water loss on _____.

A. temperature regulation B. cardiovascular responses C. metabolism D. psychological factors E. All of the above

The common molecule between the aerobic metabolism of glucose and the aerobic metabolism of a fatty acid?

AcetylCoA

Terminal ends of somatic motor neurons release _____ at the neuromuscular junction.

Ach

Which of the following is the most efficient user of oxygen?

Aerobic glycolysis of glucose

Which of the following statements is true?

Aerobic glycolysis of glucose is more oxygen efficient that the metabolism of a fatty acid.

Alternative names for skeletal muscle fibers are slow oxidative (SO), fast oxidative glycolytic (FOG), and fast glycolytic (FG). Which of the following are true statements.

All fibers have some oxidative and glycolytic capacity, but more of one than the other.

Following several months of aerobic exercise training, which of the following does NOT occur _____.

An increase in maximal HR

Which of the following is a correct concept regarding the contribution of the different metabolic pathways during exercise.

At any given intensity, all of the metabolic pathways contribute to meeting the energy demands of the exercise.

The correct interpretation of the crossover concept is that _____.

At intensities of exercise below the crossover, the body uses more fats than carbohydrates (as a percentage), and at intensities of exercise above the crossover, the body uses more carbohydrates than fats (as a percentage)

The duration and magnitude of the EPOC period _____.

B. depends primarily on the intensity and duration of the exercise C. depends on the overall physiological stress of the preceding exercise

The process of cleaving a 2-carbon unit from a fatty acid carbon chain is called _____.

Beta oxidation

Which of the following results in increased release of calcium from the sarcoplasmic reticulum of cardiac muscle cells and increased transport of calcium into the cell from the extracellular fluid?

Binding of NE to beta-1 receptors.

Bob is exercising at an intensity equivalent to 5 METs. Which of the following is a true statement about Bob's exercise?

Bob is exercising a "moderate" intensity.

At moderate intensities of aerobic exercise (60-85% of VO2max), fatigue is most likely related to _____.

C. depletion of muscle glycogen D. hypoglycemia and/or dehydration

Which of the following represents a fatty acid?

C12H24O2

What is the first priority in consuming fluids during exercise?

Consumption of an appropriate volume of fluid to manage hydration

Lactate that is produced in skeletal muscle enters the blood stream and is delivered to the liver where it is converted to glucose. The glucose then re-enters the blood stream and is delivered back to skeletal muscle where is it used in aerobic or anaerobic glycolysis. Collectively, these events are referred to as the _____.

Cori Cycle

Which of the following is an easily measured indicator of afterload?

DBP

Which of the following is the least likely to contribute to fatigue during exercise?

Depletion of triglycerides and fatty acids.

Which protein links the outermost myofibril of a muscle fiber to the sarcolemma and is therefore largely responsible for transmitting the force of contraction outward?

Desmin

In which of the following activities is anaerobic glycolysis most likely to be the predominant energy system?

Doing repeated intervals at 90% of your VO2max.

Which of the following are true regarding the insulin response to exercise and GLUT 4?

During exercise, despite a decrease in insulin levels, there is increased activation of GLUT 4 and the transport of glucose into the cell.

Which of the following represents a muscle contraction in which the force of contraction is greater than the force of resistance?

Dynamic concentric

Which of the following types of intact whole muscle contractions produces the most force?

Dynamic eccentric

Which of the following is an easily measured indicator of preload?

EDV

Compared to resting, which of the following decreases during aerobic exercise? (check all that apply)

ESV DBP TPR

If EF = 100%, that would mean _____.

ESV=0

What is the correct order of the three layers of connective tissue in skeletal muscle, beginning with outermost layer, then the middle layer, and then the innermost layer?

Epimysium, perimysium, endomysium

Which of the following is true about skeletal muscle fatigue during exercise?

Fatigue is a complex, multifaceted phenomena resulting from the interaction of many physiological and psychological factors.

Which of the following represents the formation of glycogen from glucose?

Glycogenesis

During prolonged periods of aerobic exercise, which of the following reflects the cardiac drift that is induced by dehydration_____. (check all that apply)

HR drift upward SV drifts downward Q drifts downward

In the context of metabolism, what is the role of hormones?

Hormones are essential in regulating the availability of energy substrates.

Strength training results in a sequential series of adaptations to skeletal muscle. Which of the following is the first to occur?

Improved syncronization of motor unit firing and recruitment of previously unrecruited motor units.

Which of the following terms best describes the contraction of a skeletal muscle fiber in-vitro in which the force of contraction > force of resistance?

Isotonic-shortening

How does glucose enter the skeletal muscle cell?

It is actively transported across the sarcolemma by GLUT 4

Which of the following represents the components of overload in an exercise program?

MRFIT

Of the several ways to monitor hydration status, which is the most practical and reliable to use during exercise training?

Monitor changes in body weight before and after exercise

Adrenergic receptors bind with _____.

NE and EPI

What neurotransmitter and receptor are involved in the stimulation of lipolysis during exercise.

NE and EPI / Beta 3

Compared to resting, during exercise, an increase in Q is supported by an increase in venous return of blood flow back to the heart. The increase in venous return is due, in part, to the vasoconstriction of veins. The vasoconstriction is a result of _____.

NE binding to alpha receptors

The general vasoconstriction of blood vessels on the arterial side of the circulation during exercise is a result of _____.

NE binding to alpha receptors

Which of the following is a true statement about how oxygen moves from the capillary blood into skeletal muscle?

Oxygen diffuses from the blood into the muscle due to a PO2 gradient.

As intensity of aerobic exercise increases, _____.

RER increases

When measuring blood pressure in the right arm _____.

SBP and DBP reflect pressures in the arterial side of the circulation

Pulse oximetry measures _____.

SO2 of capillary blood

Which of the following types of muscle cells are striated?

Skeletal and cardiac muscle cells

Which of the following statements is true?

Skeletal muscle stores large amounts of glycogen and small amounts of triglycerides.

Which of the following has single innervation and tonic control?

Smooth muscle in blood vessels

Steve starts his aerobic exercise training session at an intensity that is slightly above his lactate threshold.

Steve will experience a VO2 slow component in 3-5 minutes.

Which of the following statements is true?

Tetanic contractions of muscle fibers produce more force than single twitches.

What is the correct relationship between lactate and skeletal muscle fatigue?

The accumulation of lactate results in a decrease in pH which in turn contributes to fatigue.

hich of the following athletes would most likely win a 10 K race?

The athlete with the highest performance VO2 (mL/kg/min)

Lactate can be oxidized to pyruvate in which of the following (check all that apply)?

The muscle cell in which it is produced. B. A neighboring skeletal muscle cell. C. A skeletal muscle cell elsewhere in the body. D. The myocardium.

_____ is(are) highly plastic.

The nervous system and skeletal muscle?

Which of the following is related to the force of contraction of intact whole muscle?

The number, type and size of motor units recruited

What is the primary event that occurs during the fast phase of EPOC?

The replenishment of CrP.

Which of the following statements is true in regard to the control of blood flow to metabolically active skeletal muscle during exercise?

The vascular response to extrinsic factors (sympathetic vasoconstriction) is overridden by local intrinsic factors.

What three factors are suggested to athletes (or those in training) to self-monitor hydration status?

Thirst, urine color, and body weight changes.

Which skeletal muscle protein is "spring-like" and thought to contribute to the elastic properties of skeletal muscle?

Titin

Fluid intake can theoretically be ignored during relatively short durations (<60 min) of exercise if there is less than a 2% loss of body weight.

True

Compared to pre-training, as a result of strength training, which type of muscle fibers are expected to increase the most.

Type IIa

Which of the following skeletal muscle fiber types is least abundant in human skeletal muscle?

Type IIx

Which of the following represents the Fick Equation?

VO2 = Q x av-O2 diff

Which of the following is traditionally used as a measure of cardiovascular fitness?

VO2max

Parasympathetic stimulation of the heart will result in _____.

a decrease in heart rate

The pre-game meal is characterized as _____.

a high carbohydrate meal designed to increase liver and muscle glycogen stores prior to exercise

From a physiological perspective, following aerobic exercise _____.

a low-intensity active recovery is recommended

The oxygen deficit that occurs at the onset of exercise is _____.

a relative oxygen deficit (relative to steady state VO2)

Bob is planning on running a 10 K race next week. He has information measured in the lab about his VO2max and his LT. Considering the distance of the race and potential causes of fatigue, his best performance in the race would be at an intensity _____

above his LT

METs can be used as an expression of _____ intensity of exercise.

absolute

Somatic motor neurons release _____ which binds with _____.

acetylcholine; nicotinic receptors

Which of the following principles of training represents the underlying reason for regular physical activity and exercise?

adaptation

During steady-state conditions (at rest or during submaximal aerobic exercise intensities below the LT), it is assumed that _____.

aerobic metabolic pathways meet all of the energy needs of the body and the anaerobic contribution is negligible

The lactate threshold is a measure of _____.

aerobic performance

Sympathetic stimulation of the heart will result in _____.

an increase in both heart rate and force of contraction

Sympathetic stimulation of the heart will result in _____.

an increase in heart rate and force of contraction

Compared to resting, the increase in HR during exercise is related to _____.

an increase in sympathetic tone and a decrease in parasympathetic tone

The Frank-Starling Law of the heart states that _____.

an increase in ventricular filling increases stroke volume

Skeletal muscle fibers are 'typed' based on _____.

analysis of myosin heavy chains and ATPase

Characteristics of muscle fiber types lie on a continuum. One one end of the continuum are characteristics described as "glycolytic". This is synonymous with muscle fibers that _____.

are highly anaerobic

Normal contractions of intact whole skeletal muscle _____.

are tetanic in nature

Which of the following blood vessels has the greatest elastance?

arteries

Most of the CO2 produced in metabolism during exercise is transported to the lungs _____.

as bicarbonate

The availability of muscle glycogen limits the duration of aerobic exercise _____.

at moderate to high intensities (60-85% of VO2max)

Outside of the spinal cord, ganglia are part of the _____.

autonomic motor nervous system

The Poiseuille equation describes the relationship _____.

between blood flow, pressure, and resistance

Compared to pre-training, following several months of aerobic training, the decrease in HR observed at rest and during submaximal intensities of aerobic exercise is due (in part) to _____.

both an increase in parasympathetic tone and a decrease in sympathetic tone

A specific neurotransmitter _____.

can be excitatory at one location and inhibitory at another location

During exercise, _____ is the preferred energy substrate of skeletal muscle.

carbohydrates

_____ can be metabolized aerobically and anaerobically.

carbohydrates

The underlying premise of calculating the volume of fluid to be consumed during exercise in one's personal hydration plan is to _____.

consume enough fluids during exercise to lose less than 2% of the pre-exercise body weight

During short durations (<60 min) of high intensity exercise, athletes can _____

consume water only B. consume fitness waters that have a low concentration of carbohydrate to encourage drinking C. consume a sports drink D. use a carbohydrate mouth rinse to improve performance E. forego fluid consumption if there is less than a 2% loss of body weight F. all of the above

sotonic contractions occur during _____.

contractions of isolated muscle fibers

Neural stimulation of an effector organ _____.

could cause an excitatory or inhibitory response

The relationship between PO2 and %SO2 is _____.

curvilinear

Compared to resting, during exercise, ESV _____.

decreases

At the heart, ACh _____.

decreases heart rate

The shift of the oxygen association curve known as the Bohr Effect _____.

decreases the affinity of O2 for Hb

Low energy availability (EA) is concerning because it is often associated with _____.

disordered eating, osteoporosis, and amenorrhea in female athletes

when in particular is a multiple transporter carbohydrate sports drink advised?

during endurance events lasting >2.5 hours

Preload is defined as wall stress at the _____.

end of diastole

he inner layer of connective tissue networked around individual muscle fibers is the _____.

endomysium

Carbohydrate loading should be practiced prior to...

endurance events of intensities and durations in which muscle glycogen depletion is imminent and performance will be affected by depletion of muscle glycogen

During each contraction of the heart, _____.

every muscle cell will contract

At rest, arterial blood is normally fully saturated (100% SO2).

false

During a period of oxygen deficit, anaerobic metabolism is only metabolic pathway meeting the energy demands of skeletal muscle because of the lack of oxygen in the muscle.

false

T/F A decrease in the availability of fatty acids as an energy substrate becomes an increasingly likely cause of fatigue during prolonged periods of aerobic exercise (>2-3 hours)

false

T/F Neural stimulation always causes an excitatory response.

false

T/F Skeletal muscle glycogenolysis helps maintain blood glucose levels.

false

T/F: An oxygen deficit occurs only at the onset of exercise.

false

Which of the following classifications of blood vessels is described as located immediately upstream from the arterioles, have an extensive layer of smooth muscle that responds to sympathetic stimulation, and also respond to local factors that control vasoconstriction and vasodilation?

feed arteries

Which of the following represents the breakdown of glycogen to glucose in the liver?

glycogenolysis

The autonomic nervous system has antagonistic control of _____.

heart rate

The tail, neck and head regions of the myosin are formed by two intertwined (twisted) _____.

heavy chains

Susan completes and exercise test at the beginning of her training program. She finds out that at her typical running pace, her RER = 0.88. After several months of aerobic training, she repeats the same exercise test and finds out that at the same running pace, _____

her RER is lower than it was prior to her training

Pulse pressure is _____.

higher on the arterial side of the circulation than on the venous side of the circulation

Parasympathetic stimulation of the heart _____.

hyperpolarizes the SA and AV nodes

As a result of strength training, which of the following normally occurs?

hypertrophy

At low intensities of aerobic exercise (<60% of VO2max), fatigue is most likely related to _____.

hypoglycemia and/or dehydration

A neurotransmitter binds to a receptor and causes an excitatory response. In this example, the cell membrane will _____.

hypopolarize

Improved running economy (economy of movement) _____.

improves race pace

Substrate-level phosphorylation occurs _____.

in the cytoplasm and the mitochondria

Beta oxidation of a fatty acid occurs _____.

in the mitochondria of the skeletal muscle cell

Oxidative phosphorylation occurs _____.

in the mitochondria, specifically in the ETS

The benefit of carbohydrate loading prior to an endurance race is to _____.

increase the duration that race pace can be maintained

Compared to resting, during exercise, EDV _____.

increases

Compared to resting, during exercise, av-O2 difference _____.

increases

Compared to resting, during exercise, the force of contraction of the heart _____.

increases (in part) because of increased sympathetic tone

The use of muscle glycogen as an energy substrate _____.

increases as intensity of exercise increases

Compared to resting, during exercise SBP _____.

increases due to an increase in cardiac output

Increased capillarization of skeletal muscle increases the oxidative capacity of skeletal muscle by _____.

increasing transit time

Compared to resting, which of the following hormones decrease during exercise?

insulin

The predominant energy system during exercise is primarily determined by _____.

intensity and duration of the exercise

Compared to resting, the normal DBP response to aerobic exercise _____.

is a decrease in DBP due an increase in total CSA of the vasculature and a decrease in TPR

Most of the oxygen transported in the blood _____.

is bound to hemoglobin

Compared to resting, the caloric equivalent (kcal/L) during steady state aerobic exercise _____.

is greater than at rest

The blunting of the sympathetic vasoconstriction by local intrinsic factors _____.

is greatest at high intensities of exercise compared to lower intensities of exercise

In the systemic circulation, MAP _____.

is highest in the aorta and decreases through the vascular tree

Velocity of blood flow is _____.

is inversely related to the cross sectional area of the blood vessel

Most of the lactate produced during exercise _____

is oxidized to pyruvate

"Isotonic" contractions of skeletal muscle occur in _____.

isolated muscle fibers

The process of breaking down a triglyceride into 3 fatty acids and a glycerol is called _____.

lipolysis

The regulation of vascular tone to control blood flow to organs (e.g., skeletal muscle) based on metabolic activity is the primary role of _____.

local intrinsic factors

Compared to resting, an increase in blood flow specifically to active skeletal muscle during exercise is largely a result of _____.

local, or intrinsic regulation of vasodilation of feed arteries and arterioles

An aerobic exercise program designed to lose weight (body fat) that is based on the crossover concept would emphasize _____.

low intensity aerobic exercise for long durations

During contraction of skeletal muscle, muscle fibers _____.

may shorten or lengthen

The size principle states that _____.

motor units with small motor neurons are recruited before motor units with larger motor neurons

The oxygen deficit at the onset of exercise _____.

occurs because there is a temporary mismatch between the delivery of oxygen and metabolic demand

DOMS _____.

occurs only after high volumes of eccentric (negative) contractions

The rate limiting enzyme of glycolysis is _____.

phosphofructokinase

An increase in the rate of conduction (decreased delay) through the AV node is referred to as a _____.

positive dromotropic effect

As blood flows through the vasculature from the left ventricle to the capillaries _____.

pressure, velocity, and pulsatility decrease

High frequencies of stimulation of somatic motor neurons and motor units _____.

produce more force than single twitches

Skeletal muscle sarcomeres and muscle fibers _____.

produce the most force when the sarcomere or muscle fiber is slightly lengthened

Skeletal muscle _____.

produces and consumes large amounts of lactate

The "athletes heart" of an endurance trained competitive athlete can be attributed to _____.

prolonged periods of time of volume overload and eccentric hypertrophy of the left ventricle

Compared to resting, during exercise, the blood shunt _____.

redistributes and prioritizes blood flow based on metabolic demand

The 'purpose' of the Krebs Cycle is to _____.

release lots of H+ which can then be transported to the ETS.

The performance VO2 _____.

represents the highest sustainable intensity of aerobic exercise that can be maintained for prolonged durations without fatiguing due to the consequences of lactate accumulation

Susan stopped her exercise program during the COVID-19 pandemic. The loss of physical fitness that she experienced is an example of which principle of training?

reversal

The skeletal muscle cell membrane is the _____.

sarcolemma

The most basic aspect of a skeletal muscle cell in which contraction takes place is the _____.

sarcomere

When appropriate, carbohydrate replacement following exercise _____.

should begin within 30 min after exercise

Contraction of which of the following types of muscle is controlled by the recruitment of motor units?

skeletal muscle

Force of contraction is graded by the recruitment of motor units in which of the following types of muscle?

skeletal muscle

As a result of neural stimulation, _____.

some blood vessels will vasoconstrict and others will vasodilate

In which stage(s) of aerobic glycolysis are ATP resynthesized?

stage 1, 3, 4

The ATP resynthesized in the Kreb Cycle are a result of _____.

substrate-level phosphorylation

During the excitation-contraction coupling, calcium (Ca++) is released from the _____.

terminal cisternae

During steady-state aerobic exercise when the energy needs of the body are being met mostly by the metabolism of fats, _____.

the RER will be between 0.8 and 0.9

The release of ACh at the heart results in a decrease in HR because _____.

the SA and AV nodes are hyperpolarized

Functional sympatholysis refers to _____.

the ability of factors intrinsic to skeletal muscle and the local vasculature to override or blunt the sympathetic vasoconstriction that occurs during exercise

The magnitude of the oxygen deficit at the onset of exercise is most closely related to _____.

the change in metabolic demand from rest to exercise

At a given submaximal intensity of aerobic exercise (e.g., jogging at 70% of VO2max), as duration of exercise increases _____.

the contribution of blood glucose will be greater than the contribution of muscle glycogen

The size of a neuron refers to _____.

the cross-sectional area of its axon

Contraction is best defined as _____.

the development of tension

The recommended amount of carbohydrate (g/hr) to consume (as a fluid) during exercise is related to _____.

the duration of the exercise

During a prolonged period (several hours) of continuous aerobic exercise (e.g., running) at the same pace, _____.

the energy demands of the exercise would be met mostly through the use of blood borne energy substrates

As intensity of aerobic exercise increases, _____.

the energy derived from each liter of oxygen consumed increases

During steady-state aerobic exercise, it is assumed that _____.

the energy needs of the body are met only by aerobic metabolism

The maximal rate of fat oxidation (MFO) represents _____

the highest absolute (grams) amount of fat that is used during exercise

The force-velocity relationship of isolated single muscle fibers indicates that _____.

the highest velocity of shortening occurs when there is no load (resistance)

From the perspective of this class, from a metabolic perspective, fatigue during any intensity and duration of exercise is closely related to _____.

the limitations of the predominant energy system

The motor response of an organ that has dual innervation depends on _____.

the net effect of stimulation of both motor neurons

The motor response of an organ that has single innervation depends on _____.

the neurotransmitter that is released and the receptor to which it binds

The 'size' of the motor unit _____.

the number of muscle fibers in the motor unit

Hematocrit (Hct) is _____.

the portion (%) of whole blood that is red blood cells?

The blood shunt refers to the _____.

the prioritization and redistribution of blood flow to metabolically active muscle during exercise.

As intensity of aerobic exercise increases _____.

the relative contribution of carbohydrates increases and the relative contribution of fats decreases

Compared to resting, during aerobic exercise _____.

there is an increase in av-O2 diff due to increased metabolism of skeletal muscle

When cardiac muscle cells contract_____.

they will always shorten?

The oxygen bound to Hb in the blood is bound _____.

to the iron (heme) portion of the Hb

the three (3) subunits of troponin are _____.

troponin C, I and T

The proteins that are classified as having a regulatory function include _____.

troponin and tropomyosin

Most of the glycerol that comes from the lipolysis of a triglyceride _____.

undergoes gluconeogenesis in the liver

Which of the following blood vessels has the greatest compliance?

veins

The greatest amount of fat used as an energy substrate during exercise would be _____

when exercising in the fasted state

An increase in resting DBP, for example with diastolic hypertension, _____

will decrease SV by opposing the opening of the aortic valve