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ACSM Certification Review
Chapter 2
115
Physiology
Graduate
05/19/2010

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Term
What does the term "bioenergetics" refer to?
Definition
The body's ability to acquire, convert, store, and utilize energy.
Term
What is adenosine triphosphate?
Definition
The immediate source of energy for all cellular activities including muscle contraction.
Term
What is adenosine diphosphate?
Definition
ATP is broken down into it in releasing its energy.
Term
What is the phosphagen system?
Definition
An energy pathway that is composed of the ATP and phosphocreatine stored in muscle fibers.
Term
What happens through the activity of the enzyme creatine kinase?
Definition
Phosphocreatine yields its phosphate group so that it can be added to ADP to synthesize ATP.
Term
How long can stored ATP and PCr sustain exercise of all-out effort?
Definition
No more than 30 seconds.
Term
What is another term for the nonoxidative system?
Definition
The "anaerobic" pathway, because oxygen is not required for it to produce ATP.
Term
What can be used to produce ATP in this system?
Definition
Only carbs (remember that)
Term
In the absence of oxygen, what does the breakdown of carbohydrates yield?
Definition
Lactic acid (or lactate), which can contribute to muscle fatigue as it accumulates.
Term
What is the oxidative system also called?
Definition
The "aerobic" system because oxygen is required for it to proceed.
Term
What can be used to synthesize ATP by the aerobic pathway?
Definition
carbs, lipids (fats), and to a limited extent, proteins.
Term
What is oxidative phosphorylation?
Definition
It is how ATP is produced during aerobic exercise.
Term
What are the metabolic by-products that result from oxidative phosphorylation?
Definition
water and CO2, which have no fatiguing effects on working muscle.
Term
What do muscles primarily rely on to produce ATP in activities lasting more than 3 minutes and where intensity is limited.
Definition
oxidative metabolism.
Term
When one moves from nonoxidative to oxidative, that is refered to as...
Definition
the "anaerobic threshold" or the "lactate threshold".
Term
What has endurance training been shown to increase in relation to ATP?
Definition
the capacity of the oxidative system to produce ATP.
Term
How does the increase in the capacity to produce ATP happen?
Definition
increased mitochondrial density noted in muscle that has undergone prolonged endurance training.
Term
What is the purpose of skeletal muscle tissue?
Definition
To move bony levers (bones) of the skeletal system, thus enabling mobility or movement of the body.
Term
What are the types of muscle in the body?
Definition
skeletal, cardiac, and smooth.
Term
How much of the human body's mass is skeletal muscle?
Definition
nearly 50%
Term
What is the term for skeletal muscle cells?
Definition
"myocytes" or "myofibers"
Term
What is the endomysium?
Definition
a layer of connective tissue that is found wrapped around each myofiber.
Term
What do a group of as many as 150 myofibers lying in parallel bundled together form?
Definition
fasciculus.
Term
What is the layer of tissue that encases a fasciculus?
Definition
the perimysium.
Term
Each myofiber contains how many nuclei
Definition
they may possess 200-300 nuclei/mm of fiber length.
Term
What is richly developed in the myofiber as the calcium it stores is needed to stimulate muscle contraction?
Definition
the sarcoplasmic reticulum.
Term
What is the plasma membrane of the myofiber referred to as?
Definition
the sarcolemma.
Term
What two filaments account for approximately 60% of the protein content of myofiber?
Definition
myosin and actin.
Term
Compare myosin to actin.
Definition
Myosin is the larger protein sometimes called the "thick filament" and actin is the smaller of the contractile proteins and is termed the "thin filament"
Term
Other than myosin and actin, what are essention in triggering a contractile event?
Definition
troponin and topomyosin.
Term
What are the three myosin isoforms?
Definition
type I, IIA, and IIX, which correspond to the fiber types of I, IIA, and IIB
Term
What are characteristics of Type I muscle fibers?
Definition
They have slow twitch properties, but high oxidative capacity.
Term
What are characteristics of Type IIB muscle fibers?
Definition
They are fast twitch with low oxidative potential.
Term
What are characteristics of Type IIA muscle fibers?
Definition
intermediate, both in velocity and oxidative capacity.
Term
What does the sliding-filament theory of muscle contraction explain?
Definition
It explains how protein filaments interact to produce a twitch of the fiber with the following sequence of events.
1. as the nervous system excites the myofibers sarcolemma and its transverse tubules (T tubules), calcium stored within the sarcoplasmic reticulum is realeased into the cell's cytosol.
2) Calcium binds to troponin, causing the associated tropomyosin to undergo a confrmational shift (a change in shape)
3) because of this shift, "active sites" on the actin filament are exposed.
4) Cross-bridge heads located on the myosin molecule bind to the exposed active sites of actin.
5)ATPase, whcih is found in the cross-bridge head, cleaves ATP, resulting in the "power stroke" that pulls actin toward the center of the myosin molecule.
5) the entire places repeats itself so long as cytosolic calcium levels remain elevated.
UGH!
Term
What is a motor unit?
Definition
A single motor neuron and all of the myofibers that it innervates comprise a motor unit.
Term
What happens to the myofibers of a motor unit when contracted?
Definition
All contract simultaneously (all or none).
Term
All myofibers of a single motor unit are the same type?
Definition
yes.
Term
Go from smallest to largest in the muscle.
Definition
myofilaments, myofibril, muscle fiber or cell or fascicle, bundle surrounded by perimysium, muscle surrounded by fascia of epimysium.
Term
What happens to muscle fibers when training?
Definition
A conversion of type IIX to IIA will take place whether the training is endurace or resistance.
Term
What does the pulmonary system do?
Definition
Allows the body to breathe by exchanging gases with the environment.
Term
What type of breathing is most required during exercise?
Definition
Breathing through the mouth.
Term
Where do passageways through the nose and mouth join?
Definition
At the pharynx (throat)
Term
Where does inhaled air pass through after going through the pharynx?
Definition
the larynx, then the cartige-lined trachea (wind-pipe).
Term
What does the trachea then break off into?
Definition
two bronchi, which each lead to the lungs.
Term
What do the bronchi divide to form?
Definition
numerous bronchioles.
Term
What is located at the end of each bronchiole?
Definition
a cluster of alveoli.
Term
What happens in the alveoli?
Definition
gases are exchanged between the lungs and the blood traveling through the capillaries surrounding each alveolus.
Term
What happens during inhalation?
Definition
the inspiratory muscles contract to expand the volume of the thoracic cavity.
Term
Where do the diaphragm and intercostal muscles move during inhalation?
Definition
diaphragm moves downward toward the abdomen and intercostal muscles pull the rib cage up and outward.
Term
During rest, exhalation is a passive process that involves muscles moved during inhalation to go back to where they were.
Definition
During exercise though, it is an active process.
Term
What is minute ventillation?
Definition
VE is the volume of air either inspired or expired over the course of a minute.
Term
What is VE at rest?
Definition
About 6L/min
Term
During maximal intensity exercise, what can VE reach?
Definition
20 to 25 fold higher than the typical 6L/min.
Term
What is tidal volume?
Definition
the amount of air enterring or leaving the lungs in a single breath.
Term
What is respiratory rate?
Definition
number of breaths per minute.
Term
How much of the body's energy is used for breathing at rest, during moderate exercise, and during maximal exercise?
Definition
3%, 3-5%, and 10-15%
Term
When does anaerobic threshold occur in untrained individuals.
Definition
At approximately 55% of VO2 max.
Term
When does the anaerobic threshold occur in highly trained individuals?
Definition
About 80-85% of VO2 max.
Term
What is OBLA?
Definition
onset of blood lactate accumulation.
Term
What is the cardiovascular system composed of?
Definition
The heart and the blood vessels that carry blood throughout the body.
Term
what is the muscle of the heart?
Definition
the myocardium.
Term
how many chambers are in the heart? What are they?
Definition
4, the two upper chambers are the atria, and the two lower chambers are the ventricles.
Term
Where do the atria receive blood from?
Definition
left atrium from the lungs, right atrium from all other parts of the body.
Term
What separates the right and left sides of the heart?
Definition
The septum.
Term
Where does the blood go after it arrives in the atria?
Definition
To the ventricles, which then pump blood to the lungs and the rest of the body.
Term
True or false? The right and left atria contract in unison as do the right and left ventricles.
Definition
True.
Term
What is the cardiac cycle?
Definition
The sequence of events during the heart's pumping action.
Term
What is systole and diastole?
Definition
Systole refers to the contractile phase of the myocardium, and diastole is the relaxation phase between contractions.
Term
What is stroke volume?
Definition
the volume of blood ejected during each ventricular contraction which is typically 70mL.
Term
you know heart rate
Definition
yup
Term
What is cardiac output (Q)?
Definition
The amount of blood pumped from the heart by each ventricle per minute.
Term
How is Q calculated?
Definition
Q = HR x SV
Term
What is End-diastolic Volume (EDV)?
Definition
the amount of blood in each ventricle at the end of the resting phase. A normal EDV is approximately 125 mL at rest.
Term
What is the Frank-Starling Law?
Definition
It states that EDV will significantly affect SV because the greater volume of blood in the ventricle, the greater the stretch imparted on the myocardium.
Term
What is End-Systolic Volume (ESV)?
Definition
the volume of blood remaining in each ventricle at the end of its contraction. At rest it is about 55mL.
Term
What is ejection fraction? (EF)
Definition
the percentage of blood in the ventricle during diastole that is actually pumped out during systole.

EF = SV/EDV.

Under resting conditions, EF is typically 60% although it can range between 50% and 75%
Term
How much man Q be higher at maximal effort during exercise?
Definition
five to sixfold higher than at rest (25-30L/min)
Term
What happens with SV during exercise?
Definition
It increases until exercise intensity reaches approximately 50% and then it levels off.
Term
you know this, but a linear relationship exists between HR and exercise intensity.
Definition
yup
Term
What happens to EDV during exercise.
Definition
It can be as high as 160mL when SV is at its peak value.
Term
What happens to max HR during chronic aerobic training?
Definition
Nothing.
Term
What happens with resting HR with prolonged aerobic training?
Definition
it will be significantly lowered.
Term
When is SV greater? During exercise in the supine position (swimming) or during upright exercise (running or biking)? Why?
Definition
Supine. Because blood return from the legs is more efficient.
Term
What are arteries?
Definition
Thick walled, large-diameter vessels that carry blood away from the heart.
Term
What is the largest artery?
Definition
The aorta. It directly receives blood from the left ventricle.
Term
Describe each blood vessel from largest to smallest to largest again.
Definition
Ateries > arterioles > capillaries < venules < veins.
Term
What is the difference between an artery and a vein?
Definition
arteries carry blood away from the heart and veins carry blood to the heart.
Term
What system are these blood vessels a part of?
Definition
The vascular system.
Term
How do one-way valves function?
Definition
They ensure unidirectional blood flow through the network and allow for the circulation of blood within the entire body.
Term
What are sodiation and vasoconstruction?
Definition
sodilation happens during exercise when arterioles are dilated. Vasoconstruction has the opposite effect.
Term
What is blood pressure?
Definition
The force exerted by the blood on the walls of the vessel as blood is flowing through that vessel.
Term
What are afterload and preload?
Definition
The resistance imposed by the vessels as blood is pumped from the heart is termed afterload. Preload is the amount of blood in the ventricle before contraction.
Term
How do enhanced afterload and preload affect SV?
Definition
afterload is negative preload is positive.
Term
remember compliance.
Definition
will do.
Term
you know SBP and DBP.
Definition
yup.
Term
What is pulse pressure?
Definition
The difference between systolic and diastolic. In a healthy person at rest, it is approximately 40mm
Term
What is Mean Arterial Pressure? (MAP)
Definition
the average pressure exerted throughout the cardiac cycle. MAP=DBP + 1/3(SBP-DBP)
Term
What is Rate-Pressure Product (RPP) or double product.
Definition
RPP=SBPxHR
Term
What is shunting?
Definition
The moving of blood away from visceral organs to the active skeletal muscles. This happens to only 20% of blood at rest but up to 85% of blood during exercise.
Term
What happens to blood pressure during exercise?
Definition
SBP may exceed 200mm Hg during maximal intensity exercise. or 140-160 during submaximal exercise.

DBP either remains steady of decreases slightly even during maximal exercise.
Term
What should lead to the immediate cessation of exercise?
Definition
a significant drop in SBP, and increase of DBP >15 mm Hg, or SBP elevated beyond 260 mm Hg.
Term
What happens to blood pressure with prolonged exercise?
Definition
it drops, but it appears the exercise is effective only amoung those who are mildly hypertensive.
Term
How much of a person's body weight is blood?
Definition
8%
Term
What is blood composed of?
Definition
plasma, erythrocytes, leukocytes, and platelets.
Term
What are erythrocytes?
Definition
red blood cells.
Term
What is hematocrit?
Definition
a measure of the percentage of the blood's volume that is composed of red blood cells.
Term
what are leukocytes?
Definition
white blood cells.
Term
What is hyperemia?
Definition
an effect of exercise, which increases the volume of blood delivered to the working muscles.
Term
What is cardiovascular drift?
Definition
The movement of plasma out of the blood vessels and into the surrounding tissue.
Term
What is hemoconcentration?
Definition
apparent elevations in hematocrit and hemoglobin values.
Term
what is runner's anemia?
Definition
a decrease of relative measures of hemoglobin and hematocrit in well-conditioned athletes but this should not be considered a bad thing.
Term
NOTE: exercise in the supine position increases SV, which leads to a decrease in HR. (one of the review questions mentions that)
Definition
n/m
Term
How much of blood is plasma in men and women?
Definition
55 per cent in men. 58 per cent in women.
Term
What is plasma composed of?
Definition
90-93 per cent of it is water, but it is also composed of proteins, electrolytes, gases, nutrients, waste products, and various hormones.
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