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Human Anatomy & Physiology II > Chapter 19: Heart > Flashcards

Chapter 19: Heart Flashcards

1
Q

What is the major function of the heart?

A

Pump blood throughout the body.

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2
Q

What is the location of the heart?

A

The heart lies within the mediastinum between the lungs.

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3
Q

What is the pericardium?

A

A sac that encloses the heart.

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4
Q

What is the structure of the pericardium?

A

It has 2 layers – an outer fibrous pericardium and inner serous pericardium.

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5
Q

What is the function of the pericardium?

A

It separates the heart from the lungs and allows the heart to move freely as it beats.

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6
Q

What is the fibrous pericardium?

A

It is a tough collagenous sac. It surrounds the heart but is not attached to it.

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7
Q

What is the serous pericardium?

A

It is a simple squamous epithelium overlying a thin layer of elastic tissue.

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8
Q

What does the serous pericardium cover?

A

It covers the heart surface.

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9
Q

What is the membrane that covers the heart surface called?

A

The visceral layer of the serous pericardium. Also called the epicardium.

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10
Q

What is the membrane that lines the inside of the fibrous pericardium called?

A

The parietal layer of the serous pericardium.

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11
Q

What is the pericardial cavity?

A

It’s the space between the parietal and visceral layers of the serous pericardium.

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12
Q

What is pericardial fluid?

A

A fluid discharged by the serous pericardium.

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13
Q

Where is the pericardial fluid found?

A

In the pericardial cavity.

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14
Q

What is the function of the pericardial fluid?

A

It lubricates the membranes and allows the heart to beat with minimal friction.

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15
Q

What is pericarditis?

A

Inflammation of the pericardium.

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16
Q

What 3 layers does the heart wall consist of?

A

Epicardium, myocardium, and endocardium.

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17
Q

What is the outermost layer of the heart?

A

The epicardium

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18
Q

The epicardium is also called ____.

A

Visceral layer of the serous pericardium.

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19
Q

Describe the epicardium.

A

It is thin and translucent in most areas, however, in other places it includes a thick layer of adipose tissue.

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20
Q

What is the function of the thick layer of adipose tissue on the heart?

A

It encloses the major coronary blood vessels and protects them from compression.

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21
Q

What is the innermost layer of the heart?

A

The endocardium

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22
Q

Describe the endocardium.

A

It is a simple squamous epithelium overlying a thin areolar tissue layer; however, it has no adipose tissue.

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23
Q

Where is the endocardium found?

A

It lines the interior of the heart chambers, covers the valve surfaces, and is continuous with the endothelium of the blood vessels.

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24
Q

What is the layer in between the epicardium and endocardium?

A

The myocardium

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25
Q

What is the function of the myocardium?

A

It performs the work of the heart.

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26
Q

What is the thickest layer of the heart wall?

A

The myocardium

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27
Q

What is myocardium composed of?

A

Cardiac muscle

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28
Q

How is the myocardium organized? What does it form?

A

It’s organized into bundles that spiral around the heart, forming the vortex of the heart.

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29
Q

Why is the myocardium the thickest layer?

A

Because it performs the work of the heart. Its thickness is proportional to the workload on the individual chambers.

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30
Q

When the ventricles contract, they exhibit a _____ that enhances the ____.

A

Twisting or wringing motion, ejection of blood.

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31
Q

What makes up the fibrous skeleton?

A

A framework of collagenous and elastic fibers.

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32
Q

How many chambers does the heart have?

A

4

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33
Q

What are the 2 superior chambers called?

A

The right and left atria (atria for plural, atrium for singular).

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34
Q

What type of chambers are the right and left atria?

A

They are receiving chambers for blood returning to the heart by way of the great veins.

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35
Q

What are the right and left auricles?

A

They are earlike flaps on each atrium that slightly increases its volume.

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36
Q

What is the structure of the atria?

A

They have thin flaccid walls corresponding to their light workload.

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37
Q

What is the function of the atria?

A

Pump blood into the ventricles below.

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38
Q

What separates the atria?

A

The interatrial septum.

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39
Q

What do the right atrium and both auricles exhibit?

A

Pectinate muscles

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40
Q

What are pectinate muscles?

A

Internal ridges of myocardium.

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41
Q

What are the 2 inferior chambers?

A

The left and right ventricles

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42
Q

What is the function of the ventricles?

A

They eject blood into the arteries and keep it flowing around the body.

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43
Q

What separates the ventricles?

A

A thick muscular wall called the interventricular septum.

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44
Q

Where does the right ventricle pump blood to?

A

It pumps blood only to the lungs and back to the left atrium.

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45
Q

What chamber bears the greatest workload of all 4 chambers?

A

The left ventricle

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46
Q

Why is the left ventricle and septum, two to four times as thick as the right ventricle?

A

Because it bears the greatest workload of all 4 chambers.

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47
Q

Where does the left ventricle pump blood to?

A

It pumps blood through the entire body.

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48
Q

Both ventricles exhibit internal ridges called ____.

A

Trabeculae carneae

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49
Q

What is the function of trabeculae carneae?

A

It keeps the ventricular walls from clinging to each other.

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50
Q

What are the boundaries of the 4 chambers marked by?

A

The 3 sulci (grooves).

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51
Q

What are the sulci made up of?

A

They are largely filled with fat and the coronary blood vessels.

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52
Q

What are the 3 different sulci?

A

The coronary sulcus, the anterior interventricular sulcus, and the posterior interventricular sulcus.

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53
Q

Where is the coronary sulcus located?

A

It encircles the heart near the base and separates the atria above from the ventricles below.

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54
Q

What are the anterior and posterior interventricular sulci located?

A

They extend obliquely down the heart from the coronary sulcus toward the apex.

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55
Q

What interventricular sulci is on the front of the heart?

A

The anterior interventricular sulcus

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56
Q

What interventricular sulci is on the back of the heart?

A

The posterior interventricular sulcus.

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57
Q

What part(s) of the heart harbors the largest of the coronary blood vessels?

A

The coronary sulcus and the 2 interventricular sulci.

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58
Q

What is needed for the heart to pump blood effectively?

A

The heart needs valves that ensure a one-way flow.

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59
Q

Where are the heart valves located?

A

There is a valve between each atrium and its ventricle, and another at the exit from each ventricle into its great artery.

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60
Q

Does the heart have valves where the great veins empty into the atria?

A

No

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61
Q

What do the heart valves consist of?

A

Fibrous flaps of tissue covered with endocardium.

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62
Q

What are the fibrous flaps of tissues of the heart valves called?

A

Cusps or leaflets.

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63
Q

What valve regulates the openings between the atrias and ventricles?

A

The atrioventricular valves

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64
Q

What is the right atrioventricular valve called? Why?

A

The tricuspid valve. It has 3 cusps.

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65
Q

How many cusps does the left atrioventricular valve have?

A

It has 2 cusps.

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66
Q

What is the left AV valve also known as?

A

The mitral valve.

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67
Q

What connects the valve cusps to the conical papillary muscles on the floor of the ventricles?

A

Stringy tendinous chords called chordae tendineae.

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68
Q

What is the function of the chordae tendineae?

A

They prevent the AV valves from flipping inside out or bulging into the atria when the ventricles contract.

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69
Q

Each papillary muscle has 2 or 3 basal attachments to what?

A

The trabeculae carneae of the heart wall.

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70
Q

What are the semilunar valves?

A

The pulmonary and aortic valves.

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71
Q

What is the function of the semilunar valves?

A

They regulate the flow of blood from the ventricles into the great arteries.

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72
Q

What is the function of the pulmonary valve specifically?

A

It controls the opening from the right ventricle into the pulmonary trunk.

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73
Q

What is the function of the aortic valve specifically?

A

It controls the opening from the left ventricle into the aorta.

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74
Q

How many cusps do the aortic and pulmonary valves have? What do they look like?

A

Each has 3 cusps that are shaped like shirt pockets.

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75
Q

What happens when blood is ejected from the ventricles?

A

It pushes through the semilunar valves (pulmonary and aortic) from below and presses their cusps against the arterial walls.

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76
Q

What happens when the ventricles relax?

A

o Arterial blood flows back into the ventricles, but quickly fills the cusps.
o The inflated pockets meet at the center and quickly seal the opening, so little blood flows back into the ventricles.

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77
Q

Why don’t the semilunar valves require or possess tendinous chords (chordae tendineae)?

A

Because of the way they are attached to the arterial wall. They can’t prolapse any more than a shirt pocket turns inside out if you jam your hand into it.

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78
Q

Do the semilunar valves open and close by any muscular effort of their own?

A

No

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79
Q

How do the semilunar valves open and close?

A

The cusps are simply pushed open and closed by changes in blood pressure that occur as the heart chambers contract and relax.

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80
Q

Where does blood enter the heart?

A

It enters the right atrium from the superior and inferior venae cavae.

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81
Q

Where does blood travel to from the right atrium?

A

It flows through the right AV valve into the right ventricle.

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82
Q

What forces the pulmonary valve open?

A

Contraction of the right ventricle.

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83
Q

Where does blood travel to from the right ventricle?

A

It flows through the pulmonary valve into the pulmonary trunk.

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84
Q

What blood vessels distribute blood to the lungs? What does the blood unload/load?

A

The right and left pulmonary arteries. The blood drops off carbon dioxide and picks up oxygen.

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85
Q

Blood returns from the lungs to the heart by what blood vessel? What part of the heart does the blood return to?

A

Blood returns from the lungs via the pulmonary veins to the left atrium.

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86
Q

Where does blood travel to from the left atrium?

A

It flows through the left AV valve into the left ventricle.

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87
Q

What forces the aortic valve open?

A

Contraction of the left ventricle.

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88
Q

Contraction of the left and right ventricles is ____.

A

Simultaneous

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89
Q

Where does blood travel to from the left ventricle?

A

It travels through the aortic valve into the ascending aorta.

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90
Q

What happens to blood in the aorta?

A

It is distributed to every organ in the body where it drops off oxygen and picks up carbon dioxide.

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91
Q

Blood is kept entirely separate on the ____ and _____ sides of the heart.

A

Right, left

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92
Q

The myocardium has its own supply of ____.

A

Arteries and capillaries that deliver blood to every muscle cell.

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93
Q

What are the 2 major divisions of the cardiovascular system?

A

The pulmonary circuit and the systemic circuit.

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94
Q

What is the function of the systemic circuit?

A

It supplies blood to every organ of the body, including other parts of the lungs and the wall of the heart itself.

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95
Q

What is the function of the pulmonary circuit?

A

It carries blood to the lungs for gas exchange and returns it to the heart.

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96
Q

The pathways of blood flow, steps 4 through 6, is the ____ circuit.

A

Pulmonary

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97
Q

The pathway of blood flow, steps 9-11, is the ____ circuit.

A

Systemic

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98
Q

What part of the heart supplies the pulmonary circuit?

A

The right half of the heart.

99
Q

What part of the heart supplies the systemic circuit?

A

The left half of the heart.

100
Q

What is the coronary circulation?

A

A system of blood vessels that serve the wall of the heart.

101
Q

What are the major vessels of the coronary circulation?

A

The right and left coronary arteries.

102
Q

What 2 branches does the left coronary artery divide into?

A

The anterior interventricular branch and the circumflex branch.

103
Q

What 2 branches does the right coronary artery divide into?

A

The right marginal branch and the posterior interventricular branch.

104
Q

What does the right coronary artery supply?

A

The right atrium and sinoatrial node (pacemaker).

105
Q

Why is the energy demand of the cardiac muscle so critical?

A

An interruption of the blood supply to any part of the myocardium can cause necrosis within minutes.

106
Q

What can cause a myocardial infarction (heart attack)?

A

A fatty deposit or blood clot in a coronary artery.

107
Q

The points where 2 arteries come together is called ____.

A

Arterial anastomoses.

108
Q

What is the function of arterial anastomoses?

A

They provide alternative routes of blood flow (collateral circulation) that can supply the heart tissue with blood if the primary route becomes obstructed.

109
Q

When does arterial blood peak in organs other than the heart? When does it diminish?

A

o Flow usually peaks when the heart contracts and ejects blood into the systemic arteries. It diminishes when the ventricles relax and refill.

110
Q

When does arterial blood peak in the coronary arteries?

A

Flow peaks when the heart relaxes.

111
Q

When does blood flow increase in coronary blood vessels?

A

During ventricular relaxation.

112
Q

What is veinous drainage?

A

The route by which blood leaves an organ.

113
Q

Why is the heart described as autorhythmic?

A

Because it doesn’t depend on the nervous system for its rhythm.

114
Q

What allows the heart to be on its own without relying on the nervous system?

A

It has its own built-in pacemaker and electrical system.

115
Q

Cardiac muscle and skeletal muscle are both ____.

A

Striated

116
Q

What is a cardiomyocyte?

A

A cardiac muscle cell.

117
Q

What is the cell shape and dimensions of a cardiomyocyte.

A

Cardiomyocytes are short, branched and roughly rectangular.

118
Q

Describe the nucleus of a cardiomyocyte.

A

A cardiomyocyte typically has 1 centrally located nucleus

119
Q

Through the branches, each cardiomyocyte contacts several others and collectively they form ____.

A

A network throughout each pair of heart chambers – one in the atria and one in the ventricles.

120
Q

What does the cardiomyocyte lack that skeletal muscle fibers have?

A

Terminal cisterns

121
Q

Do cardiomyocytes have mitochondria?

A

Yes, due to the continuous need for contraction.

122
Q

Cardiomyocytes are joined end to end by thick connections called ____.

A

Intercalated discs.

123
Q

What is an intercalated disc?

A

A complex steplike structure with 3 distinctive features.

124
Q

What are the 3 distinctive features of an intercalated disc?

A

Interdigitating folds, mechanical junctions, and electrical junctions.

125
Q

What are interdigitating folds?

A

The plasma membrane at the end of the cell is folded somewhat like the bottom of an egg carton.

126
Q

What are mechanical junctions?

A

The cells are tightly joined by 2 types of mechanical junctions: the fascia adherens and desmosomes.

127
Q

Which of the 2 mechanical junctions if the most extensive?

A

The fascia adherens.

128
Q

What are electrical junctions?

A

The intercalated discs also contain gap junctions, which form channels that allow ions to flow from the cytoplasm of 1 cardiomyocyte directly to the next.

129
Q

What are the contractile proteins of a cardiomyocyte?

A

Actin and myosin

130
Q

What is the heartbeat coordinated by?

A

A cardiac conduction system.

131
Q

What is the cardiac conduction system composed of?

A

It is composed of an internal pacemaker and nervelike conduction pathways through the myocardium.

132
Q
A
133
Q

How does the cardiac conduction system generate and conduct rhythmic electrical signals?

A

o The sinoatrial (SA) node fires.
o Excitation spreads through atrial myocardium.
o The atrioventricular (AV) node fires.
o Excitation spreads down AV bundle.
o The subendocardial branches (Purkinje fibers) distribute excitation through ventricular myocardium.

134
Q

What is an arrhythmia?

A

A condition in which the heart beats with an irregular or abnormal rhythm.

135
Q

What is ventricular fibrillation?

A

The ventricles quiver instead of contracting normally. This prohibits the heart from pumping blood causing collapse and cardiac arrest.

136
Q

What is atrial fibrillation?

A

A weak crippling contraction in the atria, appearing in the ECG as chaotic, high-frequency depolarizations.

137
Q

What is a heart block?

A

A failure of any part of the cardiac conduction system to conduct signals, usually as the result of disease and degeneration of conduction system fibers.

138
Q

What is an atrial flutter?

A

A type of abnormal heart rhythm that occurs when the chambers beat faster than normal and not always in coordination.

139
Q

What is defibrillation?

A

An emergency procedure in which the heart is given a strong electrical shock with a pair of paddle electrodes.

140
Q

What is tachycardia?

A

A persistent, resting adult heart rate above 100 bpm.

141
Q

What causes tachycardia?

A

It can be caused by stress, anxiety, stimulants, heart disease, or fever.

142
Q

What is bradycardia?

A

A persistent resting adult hear rate below 60 bpm.

143
Q

When is bradycardia common?

A

During sleep and in endurance-trained athletes.

144
Q

What is systole?

A

The contraction phase when the heart pumps blood out.

145
Q

What is diastole?

A

The relaxation phase when the heart fills with blood.

146
Q

What is a sinus rhythm?

A

The normal heartbeat triggered by the SA node.

147
Q

How are action potentials propagated in cardiac muscle?

A

Via branching of the cells and cell: cell communication through intercalated discs. The intercalated discs contain gap junctions which allow positively charged ions (cations) to move between cells to depolarize the next cell.

148
Q

What cardiac events generates the P wave?

A

Atrial depolarization

149
Q

What cardiac event generates the QRS complex?

A

Ventricular depolarization

150
Q

What cardiac event generates the T wave?

A

Ventricular repolarization

151
Q

What are the sources of ATP used by cardiac muscle?

A

o Cardiac muscle is very rich in myoglobin which is a short-term source for aerobic respiration.
o It is also rich in glycogen which is for stored energy.

152
Q

What does cardiac muscle depend on to make ATP?

A

Cardiac muscle depends almost exclusively on anerobic respiration to make ATP.

153
Q

When given the heart rate, how do you calculate the time of 1 completed cardiac cycle?

A

Take the number 60 and divide it by the heart rate. This will give you the duration of 1 cardiac cycle in seconds.

154
Q

What 2 phases make up the cardiac cycle?

A

Diastole and systole

155
Q

Listening to the sounds made by the body is called ____.

A

Auscultation

156
Q

The first and second heart beats, symbolized S1 and S2, are often described as a ____.

A

“Lubb-dupp”

157
Q

Between S1 and S2, which heart sound is louder and longer, and which heart sound is a little softer and sharper?

A

S1 is louder and longer. S2 is a little softer and sharper.

158
Q

What cardiac event is responsible for the “lubb-dupp” (S1 and S2) sound?

A

The closing of the valves.

159
Q

What cardiac event is responsible for the “lubb” S1 sound?

A

The closing of the tricuspid and mitral valve.

160
Q

How do the tricuspid and mitral valves close?

A

The papillary muscles close shut the tricuspid valve and mitral valve by pulling on the chordae tendineae.

161
Q

What cardiac event is responsible for the “dubb” S2 sound?

A

The closing of the aortic and pulmonary valves.

162
Q

What causes the aortic and pulmonary valves close?

A

When the ventricles relax, blood flows back into the aorta and pulmonary trunk which causes the valves to close.

163
Q

What is cardiac output?

A

The amount ejected by each ventricle in 1 minute.

164
Q

What is the formula for calculating cardiac output?

A

Cardiac output = heart rate x stroke volume

165
Q

Define cardiac reserve.

A

The difference between the maximum and resting cardiac output is called the cardiac reserve.

166
Q

What are action potentials?

A

They are changes in resting membrane potential that travels for a long distance.

167
Q

What is voltage?

A

A charge separation

168
Q

What are the 3 voltage gated channels?

A

o Voltage gated sodium (Na+)
o Voltage gated calcium (Ca2+)
o Voltage gated potassium (K+)

169
Q

Voltage gated sodium (Na+) channel opens and closes ____.

A

Fast

170
Q

Voltage gated potassium (K+) channel opens and closes ____.

A

Slowly

171
Q

What are the 3 phases of action potentials?

A

o Depolarization
o Repolarization
o Hyperpolarization

172
Q

What is depolarization?

A

A decrease in polarity (less negative).

173
Q

What is repolarization?

A

Returns to polarized/resting membrane potential.

174
Q

What is hyperpolarization?

A

An increase in polarity (more negative).

175
Q

What generates and distributes action potentials throughout the cardiac muscle?

A

The intrinsic conduction system.

176
Q

Intrinsic means ____.

A

Within

177
Q

Conduction means ____.

A

Generate and distribute

178
Q

What are the 6 parts of the intrinsic conduction system (ICS)?

A

o Sinoatrial node (SA node)
o Internodal pathways
o Atrioventricular or AV node
o AV bundle of His
o Right and left bundle branches
o Purkinje fibers or subendocardial branches.

179
Q

What do modified cardiomyocytes/cardiac muscle cells lose? What does this mean?

A

They lose actin and myosin. This means they cannot contract.

180
Q

What are the cells that spontaneously generate action potentials and distribute them throughout the cardiac muscle called?

A

Autorhythmic cells

181
Q

Autorhythmic cells make up what percentage of the heart?

A

Less than 1%

182
Q

Where is the SA node located?

A

In the posterior wall of the right atrium. Below the SVC entrance.

183
Q

What is the SA node called/referred to?

A

The pacemaker of the heart.

184
Q

What is the normal rate of the SA node?

A

80-100 beats/minute.

185
Q

How big is the SA node?

A

15mm ellipsoidal tissue.

186
Q

What is the main function of the SA node?

A

It generates impulses for contractions of the heart.

187
Q

Where do action potentials generated at the SA node travel through the atria?

A

By internodal pathways.

188
Q

Where do the action potentials travel to after reaching the atria?

A

They come to the AV node.

189
Q

Where is the AV node located?

A

On the interventricular septum, superior to the tricuspid valve.

190
Q

How long do the AP’s delay at the AV node so that the atria can contract?

A

100 msec

191
Q

Where is the AV bundle/bundle of HIS located?

A

On the interventricular septum.

192
Q

The AV bundle/bundle of HIS branches into what? What is the location?

A

Branches to right and left bundle branches which travel on either side of interventricular septum, right up to the apex.

193
Q

The bundle branches become bigger in diameter called what?

A

Purkinje fibers/subendocardial network.

194
Q

Does the conduction system have a resting membrane potential? Why or why not?

A

No because they must constantly contract.

195
Q

What are the steps of the action potentials of the conduction system?

A

o At the end of hyperpolarization (#4 on graph) the membrane slowly depolarizes to -40mv (which is the threshold).
o This happens because the membrane is leaky to sodium ions, so sodium enters.
o Depolarization to threshold occurs.
o Slow depolarization (#2a on graph) is called unstable resting membrane potential or prepotential or pacemaker potential.
o After the threshold (#2b on graph) voltage gated calcium channels open. Calcium enters and membrane potential is 0 or +20mv.
o Voltage gated calcium channels close.
o Voltage gated potassium channels open. Potassium rushes out and membrane is repolarized.
o As voltage gated potassium channels close slowly, potassium leaks out more causing hyperpolarization.
o At the end of hyperpolarization, it starts all over again.

196
Q

What is an ECG/EKG?

A

An electrocardiogram

197
Q

What does an ECG/EKG record?

A

The electrical activity of the heart.

198
Q

The ECG is the sum of what?

A

Adding up the action potential of the cardiac muscle and the conduction system.

199
Q

What is a straight line in an ECG called?

A

An isoelectric line.

200
Q

What is a cardiac cycle?

A

All events in 1 single heartbeat.

201
Q

A cardiac cycle is a __________ that happens after the _________.

A

Mechanical event, electrical event

202
Q

What is the electrical event?

A

The action potential.

203
Q

How long does 1 cardiac cycle last?

A

0.8 seconds

204
Q

The R-R wave is 1 ____?

A

Cardiac cycle

205
Q

How do you figure out how many cardiac cycles occur in 1 minute?

A

You divide 60 seconds (1 minute) by 0.8 seconds (R-R wave). 60/0.8 = 75 beats/min.

206
Q

Why does the heart contract?

A

To pump blood.

207
Q

What is the heart never completely empty of?

A

Blood

208
Q

Why does the heart relax?

A

To fill with blood.

209
Q

What are the discharging chambers?

A

The ventricles

210
Q

What measures the systole?

A

The QT interval

211
Q

What is the QT interval?

A

Beginning of Q to the end of T on an ECG.

212
Q

What measures the diastole?

A

End of T to the next R.

213
Q

What are the 5 stages of a cardiac cycle?

A

o 1a. Isovolumetric relaxation
o 1b. Ventricular filling
o 1c. Atrial contraction
o 2a. Isovolumetric contraction
o 2b. Ventricular ejection

214
Q

What happens in ventricular filling of the cardiac cycle?

A

o There is minimal amount of blood in the ventricles.
o The aortic and pulmonary valves are closed.
o ¾ of the ventricles are filled with blood due to gravity/pressure gradient.
o P wave occurs.

215
Q

What happens in atrial contraction of the cardiac cycle?

A

o After the P wave occurs, the atrial contraction begins.
o It pushes the remaining ¼ of the blood into the ventricles.
o QRS wave occurs; depolarization of the ventricles happens.

216
Q

What is end diastolic volume (EDV)?

A

The volume of blood in the ventricles at the end of diastole.

217
Q

What is the measurement of EDV?

A

130mL of blood

218
Q

What happens in isovolumetric contraction of the cardiac cycle?

A

o After the QRS wave, the ventricles start to contract from the apex of heart.
o The papillary muscles close shut the tricuspid and mitral valves by pulling on the chordae tendineae.
o This creates the S1 “lubb” sound.

219
Q

What does isovolumetric mean?

A

Iso means same, volumetric has to do with volume. So, it means no change in the volume of blood.

220
Q

What happens in ventricular ejection of the cardiac cycle?

A

o As the ventricles contract, they generate pressure to open the aortic and pulmonary semilunar valves and eject blood into the aorta and pulmonary trunk.
o T wave occurs; ventricular repolarization happens.

221
Q

What blood vessel is used to measure the blood pressure of the aorta?

A

The brachial artery.

222
Q

What is the blood pressure of the aorta at the height of systole?

A

120 mm of Hg

223
Q

What is the systolic blood pressure of the pulmonary trunk?

A

25 mm of Hg

224
Q

What is end systolic volume (ESV)?

A

The volume of blood in the ventricles at the end of systole.

225
Q

What is the measurement of ESV?

A

60mL of blood.

226
Q

What is stroke volume?

A

The amount of blood pumped by the ventricles per stroke/beat.

227
Q

How do you calculate stroke volume?

A

EDV – ESV

228
Q

What happens in isovolumetric relaxation of the cardiac cycle?

A

o After the T wave, the ventricles start to relax.
o Blood flows backwards into the aorta and pulmonary trunk.
o This causes the aortic and pulmonary valves to close and makes the “dubb” S2 sound.

229
Q

What is the diastolic blood pressure of the aorta?

A

80 mm of Hg

230
Q

What is the diastolic blood pressure of the pulmonary trunk?

A

8 mm of Hg

231
Q

What does mm of Hg mean?

A

Millimeters of mercury.

232
Q

What is a dicrotic notch?

A

A brief (small) increase in aortic pressure. In an aortic pressure graph, it is shown as a double peak.

233
Q

Why is there a brief increase in aortic pressure?

A

Because of the backflow of blood into the aorta and pulmonary trunk.

234
Q

Physiologically, what does the dicrotic notch symbolize?

A

It signifies the end of ventricular contraction.

235
Q

What are the 4 heart structures that you listen to using a stethoscope?

A

Mitral valve, tricuspid valve, aortic valve, and pulmonary valve.

236
Q

Where is the location of the mitral valve heart sound?

A

Left 5th intercostal space.

237
Q

Where is the location of the tricuspid valve heart sound?

A

Right 5th intercostal space.

238
Q

Where is the location of the aortic valve heart sound?

A

Left 2nd intercostal space.

239
Q

Where is the location of the pulmonary valve heart sound?

A

Right 2nd intercostal space.

240
Q

What are capillaries?

A

Microscopic vessels that connect the smallest arteries to the smallest veins.

241
Q

What part of the body does the superior vena cava drain blood?

A

The upper body

242
Q

What part of the body does the inferior vena cava drain blood?

A

Everything below the diaphragm.

243
Q

What are the great vessels?

A

The major arteries and veins entering and leaving the heart. Called great veins, great arteries.

Human Anatomy & Physiology II (10 decks)

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