Exercise Physiology

Muscle found in the walls of the bladder is an example of

smooth muscle

Which of these is the correct order of skeletal muscle hierarchical organization, from largest structure to smallest structure?

entire muscle, muscle fasciculus, muscle fiber, myofibril

Ca2+ ions (essential for contraction) are stored in the

sarcoplasmic reticulum

Which protein is sensitive to Ca2+ and thereby helps initiate contraction?

troponin

The process of plasmalemma depolarization (increase in membrane potential) involves which ion?

Na+

Which is the correct order of events in a contraction?

T-tubule action potential, Ca2+ released, cross-bridging, Ca2+ gathered in

ATP is required for

both muscle contraction and muscle relaxation

Type I muscle fibers

have a high oxidative capacity

The speed of muscle fiber contraction is determined primarily by the

speed of myosin ATPase

Why does a sarcomere that is too short or too stretched produce less force?

Not as many cross-bridges can form.

The springlike characteristic of titan regulates force generation and prevents

overstretch

An example of an energy substrate is

palmitic acid

Which of these substrate stores in the body can provide the most overall kilocalories?

triglycerides

Protein can serve as an energy substrate if

it is first converted to glucose

Which of the following is responsible for lowering the activation energy of a chemical reaction?

enzyme activity

The anaerobic glycolytic system would be the primary source of ATP for which running event?

800 m (1/2 mi)

In the absence of oxygen, the final product of glycolysis is

lactic acid

For aerobic metabolism, free fatty acids must be converted to acetyl-CoA via

oxidation

Taking into account both oxygen requirements and ATP yield, which substrate is more efficient, fat or glucose?

Glucose is more efficient.

In which part of the cell does oxidative phosphorylation occur?

mitochondria

An athlete with a high percentage of type II fibers would exhibit which characteristics?

fewer mitochondria, lower oxidative enzymes

Men and individuals with a higher body mass index have ______ brown adipose tissue than women and individuals with a lower body mass index.

less

The somatic nervous system most specifically belongs to which division of the nervous system?

motor

The basic structural unit of the nervous system is the

neuron

If membrane potential changes from −40 mV to −35 mV, this is an example of

depolarization

The accumulation of multiple EPSPs on a postsynaptic cell is called

summation

Which neurotransmitter binds to receptors on the motor end plate of a neuromuscular junction?

acetylcholine

If membrane potential changes from −70 mV to −55 mV (with a threshold of −50 mV), what will be generated?

an excitatory postsynaptic potential (EPSP) and an action potential

The sympathetic nervous system would contribute to

increased heart rate

Which of the following is associated with the parasympathetic nervous system?

coronary arteriole constriction

Reflexes associated with Golgi tendon organs prevent skeletal muscles from

contracting with too much force

Sensory impulses that result in controlled and coordinated movements are integrated in the

cerebellum

While both the nervous and endocrine systems are critical for communication and coordination of body systems, the endocrine system responds more

slowly but has longer-lasting effects

Which of the following is a key characteristic of steroid hormones?

lipid soluble

Nonsteroid hormones are characteristically

amino acid/protein based

A key characteristic of prostaglandins is that they

exert their effects locally

For a given plasma concentration, hormone effectiveness can be altered by the

number of cell receptors

The anterior pituitary is controlled by

hypothalamic hormones

During prolonged exercise, T3 _______, while T4 _________.

decreases; plateaus

Which source of glucose is used preferentially by exercising muscle?

from muscle glycogenolysis

An increase in plasma osmolality is the stimulus for release of

aldosterone

Leptin

Is higher in obese individuals

Is secreted from adipose tissue

Increases satiety

All of the above

all of the above

Erythropoiesis increases oxygen delivery to the exercising muscle by increasing

the number of red blood cells and the volume of blood pumped

The decline in skeletal muscle _____ during high-intensity exercise above the lactate threshold dictates a greater oxygen demand to produce the same mechanical power.

efficiency

During endurance exercise, fatigue correlates best with

low glycogen stores

Glycogen depletion from muscle fiber types occurs in which order?

I, IIa, IIx

Which of the following will likely result in the most severe DOMS?

downhill-running interval training

The risk of DOMS after a given training session can be reduced by which training strategy?

reduce eccentric component of muscle action

Heat EAMCs are most effectively treated using

salt solution ingestion

Glycogen depletion directly causes fatigue during endurance exercise performance.

false

Which of the following is not true regarding lactic acid?

It is a byproduct of oxidative metabolism.

Which of the following intracellular mechanisms has notbeen shown to contribute to reduced muscle efficiency?

increased pH

The magnitude of change in body composition after exercise training is most closely related to

total energy expenditure

Which phase of the cardiac cycle is the longest?

diastole

End-diastolic volume minus end-systolic volume =

stroke volume

The pulmonary circulation encompasses all of these structures except

mitral valve

Which element of the cardiac conduction system travels along the interventricular septum?

atrioventricular bundle

The span between the QRS complex and the T wave represents which phase of the cardiac cycle?

ventricular systole

Which type of blood vessel allows exchange of nutrients, wastes, and blood gases?

capillaries

If your blood pressure is 110/70 mmHg, then your mean arterial pressure is

83 mmHg

Which mathematical factor that determines resistance has the most impact in the body?

radius of vessel

Passive vasodilation arises from

withdrawal of sympathetic influence on blood vessels

Plasma makes up approximately what percentage of whole blood?

55%

Which chambers of the heart enlarge due to intense exercise performed regularly?

left ventricle, right ventricle, left atrium, right atrium