Chapter 14 Cardiovascular Physiology

Chapter 14 – Cardiovascular
1) In the 16th century William Harvey discovered evidence that

blood is recirculated instead of consumed.

2) The most accurate definition of artery is a vessel that

transports blood away from the heart.

3) Capillaries are best described as

microscopic vessels in which blood exchanges material with the interstitial fluid.

4) Which organ is NOT known to include a special portal system for blood?

heart

5) The purpose of having valves in the cardiovascular system is to

ensure that blood flows in one direction.

6) Which artery/arteries branch(es) most proximal to the beginning of the aorta at the heart?

coronary

7) The hepatic portal vein carries blood

away from the digestive tract.

8) The medical term for heart attack is

myocardial infarction.

9) The driving force for blood flow is

a pressure gradient.

10) Each of the following changes will result in increased blood flow to a tissue except one. Identify the exception.

decreased vessel diameter

11) Which parameters are associated with increased resistance?

reduced flow

12) As blood vessel length increases

resistance increases & flow decreases.

13) When a quantity is expressed as "4 cm/sec

" what is being described?, the velocity of flow.

14) The sac around the heart is the

pericardium.

15) The function of the pericardial fluid is to

reduce friction between the heart and the pericardium.

16) In the heart valves are located between the

atria and the ventricles & between the ventricles and the arteries.

17) Which valves have chordae tendineae?

bicuspid and tricuspid valves & mitral valve

18) The term myogenic indicates that the heart muscle is the

source of the electrical signal that triggers heart contraction.

19) The action potential in a cardiac contractile cell causes

opening of L-type calcium channels.

20) Stretching a myocardial cell allows

more Ca2+ to enter & increases the force of contraction

21) The rapid depolarization phase of the action potentials of myocardial contractile cells is due to which ion(s)?

Na+

22) During the plateau phase of the action potentials of myocardial contractile cells

which ion(s) is/are crossing the membrane?, Ca2+ & K+

23) The flattening of the action potentials of myocardial contractile cells

called the plateau phase, is due to a combination of decreasing K+ permeability and increasing Ca2+ permeability.

24) The flattening of the action potentials of myocardial contractile cells

called the plateau phase, is due to a combination of increasing Ca2+influx and decreasing K+efflux.

25) The end of the plateau phase is due to the

closing of Ca2+ channels and opening of K+ channels.

26) A typical action potential of a myocardial contractile cell lasts at least

200 millisecond(s).

27) The importance of the plateau phase of the action potential of myocardial cells is in

preventing tetanus.

28) Myocardial cells can generate action potentials spontaneously because they have

unstable ion channels.

29) If channels are permeable to

Na+& K+.

30) Epinephrine and norepinephrine increase

ion flow through sodium and If channels.

31) The depolarization of the pacemaker action potential spreads

to adjacent cells through gap junctions.

32) The fibrous skeleton of the heart is important because

it forces electrical activity to be conducted through the atrioventricular node.

33) The AV node is important because it

directs electrical impulses from the atria to the ventricles & delays the transmission of the electrical impulses to the ventricles in order for the atria to finish contracting.

34) In the condition known as complete heart block what happens?

Electrical signals from the SA node never reach the ventricles, so the contraction of the atria is not coordinated with the contraction of the ventricles.

35) In electrocardiography a lead is a

pair of electrodes.

36) When the heart is in fibrillation

effective pumping of the ventricles ceases because the myocardial cells fail to work as a team, and the brain cannot get adequate oxygen.

37) Electrical shock to the heart is usually used to treat

ventricular fibrillation.

38) A heart rate of 125 beats per minute could be correctly termed

tachycardia.

39) Which event happens at the start of a cardiac cycle?

The SA node fires.

40) Which of the following events result in the first heart sound?

The AV valves close.

41) During the isovolumic phase of ventricular systole

the atrioventricular valves and semilunar valves are closed.

42) During the cardiac cycle

the QRS complex of the ECG precedes the increase in ventricular pressure.

43) The volume of blood ejected from each ventricle during a contraction is called the

stroke volume.

44) The cardiac output is equal to the product of

heart rate and stroke volume.

45) During ventricular systole

the AV valves are closed.

46) According to Starling’s law of the heart

the cardiac output is directly related to the venous return.

47) Drugs known as beta-blockers will

decrease heart rate.

48) In order for blood to enter the heart

the atria must be in diastole & the pressure in the atria must be lower than in the veins.

49) The term used to describe the amount of blood in the ventricle available to be pumped out of the heart during the next contraction is

end-diastolic volume (EDV).

50) The term that describes the volume of blood circulated by the heart in one minute is

cardiac output (CO).

51) During ventricular ejection

the ventricles are in systole.

52) Which of these will increase the heart rate?

Sympathetic stimulation to the SA node & the application of epinephrine to the SA node

53) At an intercalated disc

two cardiac muscle cells are connected by gap junctions.

54) Stimulation of the beta receptors on heart muscle results in the formation of

cAMP.

55) Which of the following statements about hydrostatic pressure is NOT true?

If a fluid is not moving the pressure that it exerts is called hydrostatic pressure & The lateral component of moving fluid represents the hydrostatic pressure.

56) Which of the following will increase flow in a vessel the most?

Increase radius by 1 unit.

57) Autorhythmic cells are also called pacemakers because they

set the rate of the heartbeat.

58) ECGs provide indirect information about the heart function and show

the summed electrical potentials generated by all cells of the heart.

59) The P wave of an ECG corresponds to the

depolarization of the atria.

60) The QRS complex of an ECG corresponds to the

progressive wave of ventricular depolarization.

61) Ventricular contraction begins

just after the Q wave.

62) Atrial contraction begins during

the latter part of the P wave.

63) QRS complex :

Immediately followed by ventricular contraction

64) PR segment :

atrial contraction

65) T wave:

ventricular repolarization

66) QRS complex:

ventricular depolarization

67) P wave:

atrial depolarization

68) cardiac output (CO):

the volume of blood circulated by the heart in one minute

69) stroke volume (SV):

the amount of blood pumped out of the heart during one contraction

70) end-systolic volume (ESV):

the amount of blood left in the ventricle after it contracts

71) end-diastolic volume (EDV):

the amount of blood in the ventricle available to be pumped out of the heart during one contraction terms:

72) tricuspid valve:

an AV valve that has three flaps

73) pulmonary valve:

a semilunar valve that has the right ventricle on one side

74) bicuspid valve:

also called the mitral valve

75) aortic valve:

has three cup like leaflets and has the aorta on one side

76) The chambers of the heart that pump blood into the arteries are the

ventricles.

77) The chambers of the heart that receive blood from the veins are the

atria.

78) The most proximal arteries to branch from the aorta are the

coronary arteries.

79) An increase in blood vessel diameter is known as

vasodilation.

80) The contraction phase of the cardiac cycle is termed

systole.

81) A resting heart rate of less than 60 beats per minute is identified as

bradycardia.

82) A resting heart rate above 100 beats per minute is identified as

tachycardia.

83) A heart with cells contracting rapidly in a disorganized manner with no effective pumping action, is said to be in

fibrillation

84) A tracing of the electrical activity of the heart monitored by electrodes placed on the skin, is called an

electrocardiogram

85) The period of time from the beginning of one heartbeat to the beginning of the next is termed the

cardiac cycle.

86) The period when blood is pushed into the arteries is called

ventricular ejection.

87) Narrowing of the opening of a heart valve is referred to as

stenosis.

88) Listening to the heart through the chest wall is called

auscultation.

89) The rule that states "Within limits the heart pumps all of the blood that returns to it" is known as the

Frank-Starling Law of the Heart.

90) The pulmonary circuit carries blood to and from the

alveoli of the lungs.

91) The systemic circuit carries blood to and from all parts of the body except the

alveoli of the lungs.

92) Arteries are blood vessels that carry blood

away from the heart.

93) Veins are blood vessels that carry blood

toward the heart.

94) The heart is enclosed in the

pericardial membrane.

95) The superior portion of the heart where the major blood vessels enter and exit is the

base.

96) The inferior point of the heart is called the

apex.

97) The septum is a wall that

separates the two sides of the heart.

98) The muscle layer of the heart wall is the

myocardium.

99) The cells responsible for establishing the rate of a cardiac contraction are the

nodal cells.

100) Abnormal patterns of cardiac activity are known as

arrhythmias.

101) The end-diastolic volume is the amount of blood in a ventricle at the beginning of

systole.

102) The end-diastolic volume is the amount of blood in a ventricle after it has contracted and before it begins to

refill.

103) The amount of blood returning to the heart is the

venous return.

104) The term for reduced blood flow to the cardiac muscle is

coronary ischemia.

105) The primary function of the cardiovascular system is to

transport material to and from all parts of the body.

106) The cardiovascular system is made up of the

heart, blood vessels and blood.

107) Name the three portal systems in the body.

1. hepatic portal system 2. renal portal system 3. hypothalamic-hypophyseal portal system

108) The pressure created in the ventricles is called the driving pressure because

it is the force that drives blood through the blood vessels

109) The heart is encased in a tough membranous sac called the prticardium and is composed mostly of cardiac muscle tissue

called the myocardium

110) The pulmonary trunk directs blood from the right ventricle of the heart to the lungs. Backflow of blood to the heart is prevented by pulmonary valve. Blood from the lungs returns blood to the heart via pulmonary veins.

…

111) The opening between each atrium and its ventricle is guarded by the atrioventricular valve

which connect the ventricular side to collagenous tendons, called chordae tendineae. Papillary muscles provide stability for these tendons.

112) Cell junctions in contractile cells are called intercalated disks

which consist of two components: desmosomes and gap junctions.

113) The ryanodine receptors are calcium channels in cardiac contractile cells.

Opening them causes calcium-induced calcium release.

114) The AV node delays the transmission of action potentials slightly to allow the atria to complete their contraction before

ventricular contraction begins.

115) Place these structures in the order that blood returning to the heart from the body would pass through them.

right atrium right ventricle pulmonary artery pulmonary vein left atrium left ventricle

116) Put these autorhythmic cells into the correct order for conveying electrical signals through a normal heart.

sinoatrial nodes internodal pathway atrioventricular node bundle of His left and right bundle branches Purkinje fibers

117) Left ventricular pressure is higher than pressure in the aorta during

ventricular diastole.

118) Abnormally slow conduction through the ventricles would change the

QRS complex in an ECG tracing.

119) A certain drug decreases heart rate by producing hyperpolarization in the pacemaker cells of the heart.

This drug probably binds to muscarinic receptors.

120) Under which set of circumstances would the diameter of peripheral blood vessels be the greatest?

decreased sympathetic stimulation

121) Acetylcholine slows the heart rate by increasing the permeability to

K+ and decreasing the permeability to Ca2+.

122) Sympathetic stimulation increases the heart rate by

increasing ion influx thus increasing the rate of depolarization.

123) Which statement is NOT true regarding cardiac muscle?

Cardiac muscle cells must obey the all-or-none law of contraction.

124) Put these phases of the cardiac cycle in the correct order.

beginning of atrial systole completion of ventricular filling beginning of ventricular systole closure of the AV valves isovolumic contraction opening of the semilunar valves ventricular ejection ventricular relaxation

125) As a result of the long refractory period

cardiac muscle cannot exhibit tetany.

126) Drugs known as calcium channel blockers can be used to

decrease the force of cardiac contraction.

127) If the membranes of the cardiac muscle cells in the SA node become more permeable to potassium ions

the heart rate will decrease.

128) The ECG of a person suffering from complete heart block would show

more P waves than QRS complexes per minute.

129) If blood pressure doubled at the same time that the peripheral resistance doubled

the blood flow through a vessel would be unchanged.

130) Which of the following conditions would have the greatest effect on peripheral resistance?

doubling the diameter of a vessel

131) If the connection between the AV node and bundle of His becomes blocked

the ventricles will beat more slowly.

132) If a myocardial infarction results in the formation of scar tissue along the pathway of the left bundle branch

cardiac arrhythmias may occur.

133) Manganese ions block the calcium channels in the cardiac muscle membrane. How would the presence of manganese in the extracellular fluid affect the contraction of the heart muscle?

The heart would beat less forcefully.

134) If there is a blockage between the AV node and the AV bundle

how will this affect the appearance of the electrocardiogram? There will be more P waves than QRS complexes.

135) In which of the following situations would the end-systolic volume (ESV) be the greatest?

when parasympathetic stimulation of the heart is increased

136) In which situation would the stroke volume be the greatest?

when venous return is increased

137) If the EDV is 140 mL which other values are most likely to occur in a healthy, normal person?

The ESV could be 70 mL and the SV could be 70 mL and The ESV could be 50 mL and the SV could be 90 mL.

138) The blood pressure in a vessel is 10 units at point A and 10 units at point B.

Flow between those points is stopped.

139) The blood pressure in a vessel is 20 units at point A and 10 units at point B. One minute later the pressure is 15 units at point A and five units at point B.

Flow between those points is unchanged

140) Joey develops a medical condition that decreases his blood viscosity. Assuming no other change (e.g.no compensatory reflex), what happens to his blood pressure?

decreased

141) When a blood vessel dilates

resistance through that vessel is decreased.

142) When a blood vessel dilates

blood viscosity is unchanged.

143) When a blood vessel dilates

velocity of blood is decreased.

144) You suck milk through a 6-inch straw and through a 10-inch straw; the diameters are identical.

Resistance is increased in the 10-inch straw compared to the 6-inch straw.

145) Blood pressure decreases during sleep. How does this affect velocity?

decreased.

146) During fasting some capillary beds in the digestive tract are closed and therefore have no blood flow. Others are open to meet the minimal need of the tract for blood flow. During eating and as long as food is present in the tract, all capillary beds open to flow. What happens to total cross-sectional area of vessels in the digestive tract?

increased

147) If total cross-sectional area of blood vessels in an organ increases what happens to velocity of blood through that organ?

decreased

148) If total cross-sectional area of vessels in an organ remains the same but blood flow to that organ increases, what happens to velocity of blood?

increased.

149) The resting membrane potential is -70 mV for skeletal muscle and -90 mV for contractile myocardium.

It is an unstable pacemaker potential (usually starts at -60 mV) for autorhythmic myocardium.

150) The rising phase of the action potential is a result of

Na+ entry for skeletal muscle, Na+ entry for contractile myocardium, and calcium entry for autorhythmic myocardium.

151) The duration of the action potential is extended: 200+ msec
in contractile myocardium, variable: generally 150+ msec in autorhythmic contractile, and short: 1-2 msec in skeletal muscle.

…

152) In the autorhythmic cellsthe If channels open when the cell membrane potential is -60 mV.

These channels are permeable to K+ and Na+.

153) Sympathetic stimulation to the pacemaker cells increases heart rate by

increasing ion flow through If and calcium channels.