Chapter 9 Heart Exercise Physiology

Front 1

The purposes of the cardiovascular system are the following
1. The transport of ______ to tissues and removal of wastes
2. The transport of ______ to tissues
3. The regulation of body ___________.

Back 1

oxygen
nutrients
temperature

Front 2

To meet the increased oxygen demands of muscle during exercise, two major adjustments of blood flow must be made..
1. an increased ______ ______ (increased amount of blood pumped per minute by the heart).
2. a redistribution of blood flow from inactive organs to the active skeletal ______.

Back 2

cardiac output
muscle

Front 3

Blood travels away from the heart in _______ and returns to the heart in ____.

Back 3

arteries
veins

Front 4

The system is considered "closed" because arteries and veins are continuous with each other through smaller _______.

Back 4

vessels

Front 5

Arteries branch until they become microscopic in the form of ___________, which eventually develop into "beds" of much smaller vessels called __________.

Back 5

arterioles
capillaries

Front 6

_________ are the smallest and must numerous of all blood vessels; all exchanges of oxygen, carbon dioxide, and nutrients between tissues and the circulatory system occur across __________ beds.

Back 6

capillaries

Front 7

Blood passes from capillary beds to small venous vessels called _______.

Back 7

venules

Front 8

As venules move back toward the heart, they increase in size and become _____.

Back 8

veins

Front 9

The mixture of venous blood from both the upper and lower body that accumulates in the right side of the heart is termed _________ ________ _______.

Back 9

mixed venous blood

Front 10

The heart is divided into four chambers and is often considered to be two pumps in one. The ______ _____ and _____ ______ form the right pump, and the ______ ______ and _____ _____ combine to make the left pump.

Back 10

right atrium
right ventricle
left atrium
left ventricle

Front 11

The right side of the heart is separated from the left side by a muscular wall called the ______________ _______. This septum prevents the mixing of blood from the two sides of the heart.

Back 11

interventricular septum

Front 12

From the superior and inferior _____ ____, blood inters the right atrium.

Back 12

vena cava

Front 13

Then through the right ___ (________) valve which has chordae tendineae, the blood flows through the right ventricle.

Back 13

AV (tricuspid)

Front 14

Through the _________ _________ valve, blood goes to the right and left __________ arteries.

Back 14

pulmonary semilunar
pulmonary

Front 15

The blood then goes to the lungs and _______ is loaded and blood comes back through the right and left _________ veins.

Back 15

oxygen
pulmonary

Front 16

After going through the veins and entering the left atrium the blood flows through the ______ (_______) ___valve to the left ventricle.

Back 16

Left (bicuspid) AV

Front 17

The blood then enters the aorta through the _______ __________ valve. The aorta branches off into arteries to the arms and legs.

Back 17

aortic semilunar

Front 18

At the lungs, ______ is loaded into the blood and _____ _______ is released.

Back 18

oxygen
carbon dioxide

Front 19

The wall of the heart is composed of three layers (1) the outer layer called the _________ (2) a muscular inner layer, the _________ (3) an inner layer known as the ___________.

Back 19

epicardium
myocardium
endocardium

Front 20

The _________ is responsible for contracting and forcing blood out of the heart and receives its blood supply from left and right coronary arteries

Back 20

myocardium

Front 21

When coronary blood flow is disrupted for more than several minutes, permanent damage to the heart occurs. This type of injury results in the death of _______ muscle cells and is commonly called a heart attack or _________ _________.

Back 21

cardiac
myocardial infarction

Front 22

heart muscle differs from skeletal muscle in several ways. First, cardiac muscle fibers are _______ than skeletal muscle fibers and are connected in a tight series. Further, cardiac muscles are tightly _______ whereas skeletal muscle fibers are elongated and do not _________.

Back 22

branched
branch

Front 23

Another difference between cardiac fibers and skeletal muscle fibers is that, unlike skeletal muscle fibers, heart muscle fibers are all connected through ___________ _____. These intercellular connections permit the transmission of electrical impulses from one fiber to another and are nothing more than leaky membranes that allow ions to cross from one fiber to another.

Back 23

intercollated discs

Front 24

When one heart fiber is depolarized to contract, all connecting heart fibers also become excited and contract as one unit. This arrangement is called a _________ syncytium.

Back 24

functional

Front 25

True/False The atria contract at the same time as the ventricles.

Back 25

False

Front 26

Is the heart muscle more similar to the type I fibers or type II fibers?

Back 26

type I

Front 27

Because the heart is more similar to type I fibers it is more (aerobic/anaerobic) and it contains large numbers of mitochondria.

Back 27

aerobic

Front 28

True/False The heart muscle is striated and contains actin and myosin filaments as well as calcium for contraction.

Back 28

True

Front 29

The contraction phase is called ________ and the relaxation phase is called _______.

Back 29

systole
diastole

Front 30

Atrial contraction occurs during ____________ relaxation.

Back 30

ventricular

Front 31

At rest, contraction of the ventricles during systole ejects about _____ -______ of the blood in the ventricles, leaving about one-third in the ventricles.

Back 31

two-thirds

Front 32

At rest a healthy female heart beats about ___ beats per minute. During heavy exercise the heart beats about ____ beats per minute.

Back 32

75
180

Front 33

In general, systole is ________ (shorter/longer) than diastole.

Back 33

shorter

Front 34

Approximately 70% of the blood entering the atria during diastole flows directly into the ventricles through the ___ valves before the atria contract.

Back 34

AV

Front 35

Upon atrial contraction, atrial pressure _____ and forces most of the remaining 30% of the atrial blood into the ventricles.

Back 35

rises

Front 36

Pressure is ___ (low/high) in the ventricles when blood is filling, but when the atria contract, the ventricular pressure increases slightly.

Back 36

low

Front 37

Then, as the ventricles contract, the pressure rises sharply, which close the ___ valves and prevents backflow into the atria.

Back 37

AV

Front 38

The occurrence of two heart sounds are produced by the closing of the ___ valves (first heart sound) and the closing of the _____ and _________ valves.

Back 38

AV
aortic
pulmonary

Front 39

_______ _________ is the force exerted by blood against the arterial walls and is determined by how much blood is pumped and the resistance to blood flow.

Back 39

Blood pressure

Front 40

The lower number in the blood pressure ratio (120/80 would be 80) is the _________ pressure.

Back 40

diastolic

Front 41

The higher number in the blood pressure ratio is the ________ pressure.

Back 41

systolic

Front 42

______ blood pressure is the pressure generated as blood is ejected from the heart during ventricular systole.

Back 42

Sysolic

Front 43

During ventricular relaxation, the arterial blood pressure decreases and represents _______ blood pressure.

Back 43

diastolic

Front 44

The difference between systolic and diastolic blood pressure is called the ______ pressure.

Back 44

pulse

Front 45

The average pressure during a cardiac cycle is called the ______ ________ ________ and is important because it determines the rate of blood flow through the systemic circuit.

Back 45

mean arterial pressure

Front 46

____________ is defined as blood pressure in excess of the normal range for the person's age and sex.

Back 46

hypertension

Front 47

Hypertension increase the workload on the _____ ventricle resulting in an adaptive increase in the muscle mass of the left heart (called left ventricular hypertrophy.

Back 47

left

Front 48

Arterial blood pressure is determined by ______ _______, the amount of blood pumped from the heart and ______ __________ _________, the sum of resistance to blood flow provided by all systemic blood vessels.

Back 48

cardiac output
total vascular resistance

Front 49

Acute regulation of blood pressure is achieved by the _________ nervous system, whereas long-term regulation of blood pressure is primarily a function of the _______.

Back 49

sympathetic
kidneys

Front 50

Pressure receptors (called __________) in the carotid artery and the aorta are sensitive to changes in arterial blood pressure. An increase in arterial blood pressure triggers these receptors to send impulses to the cardiovascular control center i, which responds by ________ (increasing/decreasing) sympathetic activity.

Back 50

baroreceptors
decreasing

Front 51

Action potentials generate in the ___ node (pacemaker) and travel across the wall of the atrium from the SA node to the ___ node.

Back 51

SA
AV

Front 52

Action potentials pass through the AV node, and along the ___ _______, which extends from the AV node, through the fibrous skeleton, into the ___________ ________.

Back 52

AV bundle
interventricular septum

Front 53

The AV bundle divides into right and left ______ ________ and action potentials descend to the apex of each ventricle along the bundle branches.

Back 53

bundle branches

Front 54

Action potentials are carried by the _______ ______ from the bundle branches to the ventricular walls.

Back 54

purkinje fibers

Front 55

When the SA node reaches the __________ threshold and "fires", the wave of depolarization spreads over the atria, resulting in atria _________.

Back 55

depolarization
contraction

Front 56

The wave of atrial depolarization cannot directly cross into the ventricles but must be transported by way of specialized conductive tissue. This specialized conductive tissue radiates from the small mass of muscle tissue called the ___ _____.

Back 56

AV node

Front 57

This node, located in the floor of the right atrium, connects the atria with the ventricles by a pair of conductive pathways called ____ and ____ __bundle branches.

Back 57

left
right
AV

Front 58

Upon reaching the ventricles, these conductive pathways branch into smaller fibers called ________ ______.

Back 58

Purkinje fibers

Front 59

The Purkinje fibers then spread the wave of depolarization throughout the ________.

Back 59

ventricles

Front 60

A recording of the electrical changes that occur in the myocardium during the cardiac cycle is called an ____________.

Back 60

electrocardiogram

Front 61

The first deflection on the ECg is called the P wave and represents the ___________ of the atria.

Back 61

depolarization

Front 62

The second wave, the QRS complex, represents the depolarization of the ________ and occurs approximately ___ seconds after the P wave.

Back 62

ventricles
0.10

Front 63

The final deflection, the T wave, is the result of _________ ___________.

Back 63

ventricular repolarization

Front 64

Atrial repolarization occurs during the ____ complex.

Back 64

QRS

Front 65

The QRS complex occurs at the beginning of _______ (systole/diastole), where as the T wave occurs at the beginning of (systole/diastole)

Back 65

systole
diastole

Front 66

The rise in intraventricular pressure at the beginning of ______ results in the first heart sound due to closure of ___ valves and the fall in intraventricular pressure at the end of systole results in the second heart sound due to close of the ______ and __________ semilunar valves.

Back 66

systole
AV
aortic
pulmonary

Front 67

During ventricular depolarization, depolarization begins at the _____ and progresses superiorly as atria repolarize.

Back 67

apex

Front 68

During the P wave, _____ contract.

Back 68

atria

Front 69

During the QRS complex, ________ contract as _______ relax

Back 69

ventricles
atria

Front 70

The __-__ segment indicates there is a problem in ventricular areas and are primary concern because they do 75-85% of the work.

Back 70

S-T

Front 71

_______ ________ can be increased by one or all of the following factors:
a. Increase in blood volume
b. Increase in heart rate
c. Increased blood viscosity
d. Increase in stroke volume
e. Increased peripheral resistance

Back 71

Blood pressure

Front 72

______ ______ is defined as the amount of blood pumped by the heart each minute.

Back 72

Cardiac output

Front 73

Cardiac output is a product of ___ and ___.

Back 73

HR and SV
heart rate and stroke volume

Front 74

Because the ___ node controls heart rate, changes in heart rate often involve factors that influence the SA node. The two most important factors that influence heart rate are the ______________ and ____________ nervous systems.

Back 74

parasympathetic
sympathetic

Front 75

The parasympathetic fibers that supply the heart arise from neurons in the cardiovascular control center in the medulla oblongata and make up a portion of the ____ nerve.

Back 75

vagus

Front 76

Upon reaching the heart, these fibers make contact with both the SA node and the AV node. When stimulated, these nerve endings release ____________, which causes a (decrease/increase) in the activity of both the SA and AV nodes due to _____________, slowing heart rate.

Back 76

acetylcholine
hyperpolarization

Front 77

Even at rest, the vagus nerves carry impulses to the SA and AV nodes. This is often referred to as ___________ _____.

Back 77

parasympathetic tone

Front 78

At higher work rates, stimulation of the SA and AV nodes by the sympathetic nervous system is responsible for increases in heart rate. Sympathetic fibers reach the heart by means of ______ __________ nerves, which innervate both the SA node and ventricles.

Back 78

cardiac accelerator

Front 79

Endings of the cardiac accelerator nerves release _____________ upon stimulation, which act on beta receptors in the heart and cause an increase in both heart rate and the force of myocardial contraction.

Back 79

norepinephrine

Front 80

One variable that effects stroke volume is the ___-_______ ________ , which is the volume of blood in the ventricles at the end of diastole ("pre-load" for systole).

Back 80

end-diastolic volume

Front 81

Frank and Starling demonstrated that the strength of ventricular contraction (increased/descreased) with an enlargement of end-diastolic volume.

Back 81

increased

Front 82

The principle variable that influences EDV is the rate of _____ return to the heart.

Back 82

venous

Front 83

The factors that influence venous return to the heart and EDV are constriction of the veins (______________), pumping action of _______ muscle (called the muscle pump), and the pumping action of the __________ system (respiratory pump)

Back 83

venoconstriction
skeletal
respiratory

Front 84

Another variable that affects stroke volume is the _____ ________ blood pressure and is the pressure the heart must pump against to eject blood, also known as mean arterial pressure.

Back 84

average aortic

Front 85

In order to eject blood, the pressure generated by the left ventricle must exceed the pressure in the ______. Therefore, aortic pressure or mean arterial pressure (called afterload) represents a barrier to the ejection of blood from the ventricles.

Back 85

aorta

Front 86

An increase in aortic pressure produces a (decrease/increase) in stroke volume.

Back 86

decrease

Front 87

The final factor that influences stroke volume is the effect of circulating __________-___________ and direct sympathetic stimulation of the heart by cardiac accelerator nerves.

Back 87

epinephrine-norepinephrine

Front 88

Venoconstriction is regulated by the parasympathetic or sympathetic with regard to EDV?

Back 88

sympathetic

Front 89

Skeletal muscle pump causes rhythmic skeletal muscle contractions to force blood in the extremeties _______ the heart with regard to EDV

Back 89

toward

Front 90

The respiratory pump causes changes in ________ pressure which pulls blood towards the heart with respect to EDV.

Back 90

thoracic

Front 91

True/False The skeletal muscle pump closes valves so that the blood will circulate towards the heart.

Back 91

True

Front 92

Blood is composed of
1. ______: the liquid portion of blood that contains ions, proteins, and hormones.
2. ____ ______ _____: contain hemoglobin to carry oxygen
3. _____ ______ _____: important in preventing infection
4. _________: important in blood clotting

Back 92

plasma
red blood cells
white blood cells
platelets

Front 93

A ________ is the percentage of blood composed of cells.

Back 93

hematocrit

Front 94

The average hematocrit of a normal college-age male is ___% and the hematocrit of a normal college-age female is ___%

Back 94

42
38

Front 95

Blood flow is _____ proportional to the pressure difference between two ends of the system.

Back 95

directly

Front 96

Blood flow is _______ proportional to resistance.

Back 96

inversely

Front 97

Resistance to blood flow is directly proportional to the length of the ______ and the _______ of the blood.

Back 97

vessel
viscosity

Front 98

If you increased the diameter of a blood vessel would it decrease or increase resistance?

Back 98

decrease

Front 99

Resistance depends on:
______ of blood vessel
______ of the blood
______ of the vessel

Back 99

length
viscosity
radius

Front 100

Blood can be diverted from one organ system to another by varying degrees of vaso_______ and vaso________. This principle is used during heavy exercise to divert blood toward contracting muscles and away from less-active tissue.

Back 100

constriction
dilation

Front 101

The greatest vascular resistance occurs in
a. venules
b. arteries
c. veins
d. arterioles
e. capillaries

Back 101

d. arterioles

Front 102

Oxygen demand by muscles during exercise is ___-___x greater than at rest

Back 102

15-25

Front 103

Increased oxygen delivery is accomplished by:
1. increased ________ _______
2. redistribution of ______ ______ from inactive organs to working skeletal muscle

Back 103

cardiac output
blood flow

Front 104

The vO2 difference represents the amount of oxygen that is taken up from ____ mL of blood by the tissues during one trip around the ________ circuit. This is the change in the arterial mixed venous oxygen difference that occurs during exercise.

Back 104

100
systemic

Front 105

The relationship between cardiac output (Q) a - v-O2, and oxygen uptake is given by the Fick equation. Write the Fick equation.

Back 105

VO2 = Q x (a-v-O2 diff)

Front 106

To meet the increased needs of the skeletal muscle during exercise, it is necessary to increase muscle blood flow while reducing blood flow to less active organs of the gastrointestinal region. The increase in muscle blood flow during exercise and the _______ in splanchnic blood flow change as a ________ function of % VO2 max.

Back 106

decrease
linear

Front 107

At rest, approximately __ to ___% of total cardiac output is directed toward skeletal muscle. During maximal exercise, ___ to ___% of total cardiac output goes to contracting skeletal muscle

Back 107

15-20
80-85

Front 108

At the beginning of exercise, the initial skeletal muscle vasodilation that occurs is due to an intrinsic metabolic control. This type of blood flow regulation is termed ____________, and it is thought to be the most important factor in regulating blood flow to muscle during exercise.

Back 108

autoregulation

Front 109

The increased __________ rate of skeletal muscle during exercise causes local changes such as decreases in oxygen tension, increases in CO2 tension, nitric oxide, potassium and adenosine concentrations, and a decrease in pH (increase in acidity).

Back 109

metabolic

Front 110

While the vascular resistance decreases to skeletal muscle during exercise, vascular resistance _______ and decreases blood flow in the visceral organs and other inactivity tissues.

Back 110

increases

Front 111

The changes in heart rate and blood pressure that occur during exercise reflect the type and intensity of the ______ performed, the _______ of exercise, and the __________ conditions under which the work was performed.

Back 111

exercise
duration
environmental

Front 112

Submaximal exercise in an emotionally charged atmosphere results in _____ heart rates and blood pressures when compared to the same work in a psychologically "neutral" environment.

Back 112

increased

Front 113

At the same oxygen uptake, ____ work results in a higher heart rate due to higher sympathetic stimulation and blood pressure due to vasoconstriction of large inactive muscle mass.

Back 113

arm

Front 114

The increased heart rate that occurs during prolonged exercise is called _____________ ______.

Back 114

cardiovascular drift

Front 115

The central command theory of cardiovascular control during exercise proposes the initial signal to "drive" the cardiovascular system at the beginning of exercise comes from higher ______ centers.

Back 115

brain

Front 116

Although central command is the primary drive to increase heart rate during exercise, the cardiovascular response to exercise is fine-tuned by feedback from muscle ____________, muscle ________________, and arterial __________ to the cardiovascular control center.

Back 116

chemoreceptor
mechanoreceptor
baroreceptor