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Anatomy & Physiology 2nd Sem. > Chapter 11 Cardiovascular System Part 1 (Slide #1-62) > Flashcards

Chapter 11 Cardiovascular System Part 1 (Slide #1-62) Flashcards

1
Q

From superficial to deep, name the layers of the heart wall.

A
  1. Epicardium(visceral pericardium)
  2. Myocardium
  3. Endocardium
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2
Q

Why is it important that cardiac tissue be richly supplied with mitochondria and capillaries

A

Cardiac tissue is metabolically active and dependent on mitochondrial activity for ATP obtaining oxygen and nutrients from local capillaries

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3
Q

Describe the heart’s location

A

Located within the pericardial sac in the anterior mediastinum, deep to the sternum and superior to the diaphragm

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4
Q

Name and describe the shallow depressions and grooves found on the heart’s external surface.

A

Anterior interventricular sulcus marks the boundary b/t the left and right ventricles on the heart’s anterior surface;
the shallower posterior interventricular sulcus marks the boundary b/t the left and right ventricles on the posterior surface; and the coronary sulcus is a deep groove that marks the border b/t the atria and the ventricles

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5
Q

Describe what happens to blood flow in the aorta during elastic rebound.

A

Some blood in aorta is driven forward into the systemic circuit, and some is forced back toward the left ventricle and into the coronary arteries

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6
Q

Identify the main vessel that drains blood from the myocardial capillaries.

A

Cardiac vein

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7
Q

Damage to the semilunar valve on the right side of the heart would affect blood flow to which vessel

A

-would affect blood flow to the pulmonary artery

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8
Q

What prevents the AV valves from swinging into the atria?

A

It pulls on the chordae tendinae

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9
Q

Why is the left ventricle more muscular than the right ventricle

A

Because the left ventricle has to be able to pump blood through the whole body and the right ventricle only has to send it to the lungs

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10
Q

Provide the alternate terms for the contraction and relaxation of heart chambers.

A

for contraction= systole

for relaxation= diastole

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11
Q

Describe the phases of the cardiac cycle.

A
  • atrial systole
  • atrial diastole
  • ventricular systole
  • ventricular diastole
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12
Q

Is the heart always pumping blood when pressure in the left ventricle is rising? Explain

A

No.

  • when pressure in the L ventricle 1st rises, the heart is contracting BUT no blood is leaving the heart
  • during the initial phase of contraction, BOTH the AV valves and semilunar valves are CLOSED
  • the increase in pressure is the result of increased tension as the cardiac muscle contracts
  • when the pressure in the ventricle EXCEEDS the pressure in the aorta, the aortic semilunar valves are FORCED OPEN, and blood is rapidly EJECTED from the ventricle
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13
Q

Describe the sites and actions of the cardioinhibitory and cardioacceleratory center

A

The cardioacceleratory center in the medulla oblongata activates sympathetic neurons to increase heart rate;

the cardioinhibitory center (also in the medulla oblongata) controls the parasympathetic neurons that slow heart rate

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14
Q

Compare bradycardia with tachycardia.

A
  • Bradycardia is a heart rate below 60 beats per minute;

- tachycardia is a heart rate above 100 beats per minute

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15
Q

List five important features of the ECG, and indicate what each represents

A

1.the P wave (atrial depolarization),

2 .the QRS complex (ventricular depolarization)

3.T wave (ventricular repolarization
4.
5.

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16
Q

Define Cardiac output

A

-the blood volume (in liters) ejected per minute by the left ventricle

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17
Q

Why is it a potential problem if the heart beats too rapidly?

A

the heart pumps in proportion to the amount of blood that enters. a heart that beats too rapidly does not have sufficient time to fill completely between beats. thus, when the heart beats too fast, very little blood leaves the ventricles and enters the circulation so tissues suffer damage from inadequate blood supply.

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18
Q

Define blood flow, and describe its relationship to blood pressure and peripheral resistance

A

BLOOD FLOW is

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19
Q

What is the relationship between blood pressure and blood flow?

A

increased blood pressure = increased blood flow

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20
Q

What is the relationship between resistance and blood flow?

A

increased resistance = decreased blood flow

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21
Q

Which vessels endure the highest blood pressure?

A

Aorta and large arteries

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22
Q

In a healthy individual, is blood pressure higher in the aorta or in the inferior vena cava? Explain.

A

Blood pressure is greater at the aorta than at the inferior vena cava. If the pressure were higher in the aorta, blood would flow in the reverse direction.

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23
Q

Describe autoregulation as it pertains to cardiovascular function.

A

Involves local factors changing the pattern of blood flow within capillary beds in response to chemical changes in interstitial fluids

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24
Q

Explain the function of baroreceptor reflexes

A
  • Rapid,
  • SHORT TERM,
  • reflex adjustments to MAP (blood pressure).
  • Controls MAP by regulating CO and TPR.

Recheck!

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25
Q

Describe the changes in cardiac output and blood flow during exercise.

A
  1. vasodilatation occurs, peripheral resistance drops, and blood flow through the capillaries increases
  2. venous return increases as skeletal muscle contractions squeeze blood along the peripheral veins at the same time, each inhalation, creates negative pressures in the thoracic cavity that pulls blood into the vena cava from their branches. This mechanism is called the respiratory pump
  3. Cardiac output rises, primarily due to the increased venous return
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26
Q

Why does blood flow to visceral organs decrease during exercise?

A

Major changes in the peripheral distribution of blood allow a massive increase in blood flow to skeletal muscles while preventing a potentially disastrous decline in systemic stimulation

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27
Q

List the five general classes of blood vessels

A 
1-arteries
2-arterioles
3-capillaries
4-venules
5-veins
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28
Q

Describe a capillary.

A

Numerous tiny vessels that allow for the exchange of substances between the blood and body tissues

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29
Q

What is the role of precapillary sphincters

A

a muscle fiber that regulates blood flow into the capillary bed

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30
Q

Describe blood flow through an arteriovenous anastomosis

A

Vessels through which blood is shunted from arterioles to venules without passing through the capillaries

-Google

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31
Q

Define varicose veins.

A

a structural defect due to incompetent valves, is a common vascular problem, especially in the obese and people who stand for long hours. It is a predisposing factor for thrombophlebitis.

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32
Q

Why are valves located in veins, but not in arteries?

A

veins need valves to create pressure to pump the blood to the heart. valves assist in returning venus blood to the heart.

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33
Q

How is blood flow maintained in veins to counter the pull of gravity?

A
  • Contraction of the surrounding skeletal muscles squeezes venous blood toward the heart.
  • This mechanism, the muscular pump, is assisted by the presence of valves in the veins, which prevent back flow of the blood. The respiratory pump, which results from the increase in internal pressure of the thoracic cavity during exhalation pushes blood into the right atrium.

Recheck!

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34
Q

Identify the two circulatory circuits of the cardiovascular system

A
  1. Pulmonary system (system that goes to the lungs)

2. Systemic system (system that goes to the rest of the body

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35
Q

Trace the path of a drop of blood through the lungs, beginning at the right ventricle and ending at the left atrium.

A

right ventricle –> right and left pulmonary arteries –> pulmonary arterioles –> alveolar capillaries –> pulmonary venues –> pulmonary veins –> left atrium

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36
Q

Name the two large veins that collect blood from the systemic circuit

A

aorta

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37
Q

Identify the largest artery in the body.

A

aorta

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38
Q

Trace Besides containing valves, cite another major difference between the arterial and venous systems

A

existence of dual venous drainage in the neck and limbs

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39
Q

Name the two arteries formed by the division of the brachiocephalic trunk.

A

right common carotid artery and the right subclavian artery

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40
Q

Name the two arteries formed by the division of the brachiocephalic trunk.

A

right common carotid artery and the right subclavian artery

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41
Q

A blockage of which branch from the aortic arch would interfere with blood flow to the left arm?

A

A blockage of the left subclavian artery would interfere with blood flow to the left arm.

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42
Q

Identify the branches of the celiac trunk

A

3 Immediate Branches

left gastric artery
splenic artery,
common hepatic artery

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43
Q

The distal end of this artery contains receptors (baroreceptors) for blood pressure regulation.

A

Carotid

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44
Q

Name the arterial structure in the neck region that contains baroreceptors.

A

Carotid

Recheck!

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45
Q

Identify the veins that combine to form the

brachiocephalic vein.

A

external jugular
internal jugular
vertebral
subclavian veins

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46
Q

Which vessel collects most of the venous blood inferior to the diaphragm

A

Inferior vena cavae

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47
Q

List the unpaired branches of the abdominal aorta that supply blood to the visceral organs

A

celiac trunk, superior mesenteric artery, inferior mesenteric artery

Recheck!

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48
Q

Identify the three veins that merge to form the hepatic portal vein.

A

gastric

inferior mesenteric

superior mesenteric

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49
Q

what is the location of the heart in the thorax

A

the heart is in the mediastinum between the lungs

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50
Q

which heart chamber has the thickest walls? What is the functional significance of this structural difference?

A

the left ventricle has the thickest walls. This reflects its function, which is to pump blood through the whole body.

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51
Q

how does the function of the systemic circulation differ from that of the pulmonary circulation?

A

Pulmonary circulation strictly serves gas exchange. Oxygen is loaded and CO2 is unloaded from the blood in the lungs. Systemic circiulation provides oxygen laden blood to all body organs.

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52
Q

why are the heart valves important

A

keep blood flowing forward through the heart

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53
Q

Why might a thrombus in a coronary artery cause sudden death?

A

The coronary artery supply the myocardium( cardiac muscle) with oxygen. If that circulation fails, the heart fails.

54
Q

Are the ventricular Cardiac Cells contracting isometrically or isotonically during the first part of
phase 2?

A

The cells contract Isometrically until they have enough force to overcome the back pressure of the blood against the seminular valves, at which point their contraction become isotonic

55
Q

What is the function of the intrinsic conduction system of the heart?

A
  • coordinates the actions of the heart chambers and causes the heart to beat faster than it would other wise
56
Q

To which heart chambers do the terms systole and diastole usually apply?

A

Left Ventricle

57
Q

What causes the lub-dub sounds heard with a stethoscope?

A

The operation of the heart valves

58
Q

What does the term cardiac output mean?

A

Amt of blood pumped out by each side of the heart by 1 minute.

59
Q

What would you expect to happen to the heart of an individual with a fever? Why?

A

Fever increases the heart rate bec. the rate of metabolism of the cardiac muscle increases.

60
Q

What is the most important factor affecting stroke volume?

A

Venous return

61
Q

Assume u are viewing a blood vessel under the microscope. It Has a large lopsided lumen, relatively thick tunica externa, and arelatively thin tunica media. Which kind of blood vessel is this?

A

It is a vein.

62
Q

Assume u are viewing a blood vessel under the microscope. It Has a large lopsided lumen, relatively thick tunica externa, and arelatively thin tunica media. Which kind of blood vessel is this?

A

It is a vein.

Till #12 only.

63
Q

The Cardiovascular System

A

*A closed system of the heart and blood vessels

  • The heart pumps blood
  • Blood vessels allow blood to circulate to the body

*Functions to deliver oxygen, nutrients and hormones while removing carbon dioxide and other waste products

64
Q

What is the location of the heart?

A

Thorax between the lungs in the inferior mediastinum

65
Q

What is the Orientation of the heart?

A

Pointed apex lies in the 5th / 6th ICS

Base points toward right shoulder

66
Q

What is the Size of the heart?

A

About the size of your fist

Weighs less than a pound

67
Q

The Heart Coverings

A

Pericardial sac

Pericardial cavity

68
Q

Pericardial sac

A

Surrounds heart

Formed by parietal pericardium

69
Q

Pericardial cavity

A

*Bounded by two serous membranes

  • Visceral pericardium (epicardium) attached to heart
  • Parietal pericardium forming outer wall of cavity

*Contains 15–50 mL pericardial (serous) fluid (secreted by visceral pericardium

70
Q

Cardiac Muscle Tissue

A
  • Smaller cell size than skeletal muscle tissue
  • Branching interconnections between cells
  • Specialized intercellular connections

-Intercalated discs:
= Gap junctions
= Desmosomes

71
Q

Cardiac Muscle Cells

A
  • Found only in heart - cardiomyocytes
  • Dependent on aerobic metabolism
  • High quantity of mitochondria
  • High myoglobin reserves
  • Extensive capillary supply
72
Q

Three Layers of the Heart

A
  1. Epicardium (visceral pericardium)
  2. Myocardium
  3. Endocardium
73
Q

1.Epicardium (visceral pericardium)

A
  • Serous membrane covering outer surface of heart

- Attached to myocardium

74
Q

2.Myocardium

A
  • Muscular wall of heart composed of concentric layers of cardiac muscle tissue
  • Also contains blood vessels and nerves
75
Q

3.Endocardium

A

Endocardium
Simple squamous epithelium with underlying areolar tissue

Lines inner surfaces of heart including

76
Q

3.Endocardium

A

Simple squamous epithelium with underlying areolar tissue

Lines inner surfaces of heart including

77
Q

Four chambers of the heart

A

Atria:

  1. Right atrium
  2. Left atrium

Ventricles:

  1. Right ventricle – pumps deoxygenated blood into pulmonary circulation – low pressure
  2. Left ventricle - pumps oxygenated blood to systemic system – high pressure
78
Q

The Heart: Septa

A

Interventricular septum

Interatrial septum

79
Q

Interventricular septum

A

separates the ventricles

80
Q

Interatrial septum

A
  • separates the atria
81
Q

The Heart: Valves

A
  • Lie at both entrances and exits of the ventricles
  • Four valves – 2 AV valves and 2 semilunar valves
  • Flaps/cusps held in place by chordae tendineae (“heart strings”)
82
Q
  1. Atrioventricular valves (AV)
A
  • Found between atria and ventricles

* allows flow into ventricles - closure of these valves make the 1st heart sound (lub)

83
Q

Atrioventricular valves (AV) (Contd)

A

Bicuspid or Mitral valve (left)

Tricuspid valve (right

84
Q
  1. Semilunar valves
A
  • controls flow of blood out of R and L ventricles
  • closure of these valves cause the 2nd heart sound (dub)
  • Pulmonary valve (right)
  • Aortic valve (left)
85
Q

a) Operation of the AV valves

A
  1. Blood returning to the
    atria puts pressure against
    AV valves; the AV valves
    are forced open.
  2. As the ventricles fill,
    AV valve flaps hang
    limply into ventricles.
  3. Atria contract,
    forcing additional
    blood into ventricles

AV valves open;
atrial pressure
greater than
ventricular pressure

  1. Ventricles contract,
    forcing blood against
    AV valve flaps
  2. AV valves close
  3. Chordae tendineae
    tighten, preventing
    valve flaps from
    everting into atria

AV valves closed;
atrial pressure
less than
ventricular pressure

86
Q

b. Operation of the semilunar valves

A 
1.As ventricles contract
and intraventricular
pressure rises, blood
is pushed up against
semilunar valves,
forcing them open.

Semilunar valves open

2. As ventricles relax
and intraventricular
pressure falls, blood
flows back from
arteries, filling the
leaflets of semilunar
valves and forcing
them to close.

Semilunar valves closed

87
Q

Heart Sounds

A

*Produced by heart valves closing, blood rushing through heart, or heart muscle contracting

  • First sound “lubb” (S1) longer than second
  • Marks start of ventricular contraction
  • Produced as AV valves close
  • Second sound “dupp” (S2)
  • Occurs when semilunar valves close
  • Third and fourth sounds from blood flowing into ventricles (S3) and atrial contraction (S4)
  • Usually very faint and not heard in healthy adult
88
Q

Coronary Circulation

A

The heart has its own blood supply

89
Q

Coronary arteries

A
  • branch from the aorta
90
Q

Cardiac veins

A

drain the myocardium

91
Q

Coronary sinus

A

large vein on the posterior of the heart, receives blood from cardiac veins  drains into the right atrium

92
Q

The Heart: Associated Great Vessels

A

Aorta

Pulmonary arteries (2)

Vena cava (2)

Pulmonary veins (4)

93
Q

Aorta

A

– oxygenated blood

Carries blood from left ventricle out to the body

94
Q

Pulmonary arteries (2)

A
  • deoxygenated blood

Carries blood from right ventricle to the lungs

95
Q

Vena cava (2) –

A

–deoxygenated blood

Carries blood from body to right atrium

96
Q

Pulmonary veins (4) –

A

–oxygenated blood

Carries blood from lungs to left atrium

97
Q

Blood Flow Through the Heart

A

ORDER:

  • from Venae cava (superior and inferior)
  • right atrium
  • through the tricuspid valve
  • right ventricle 
  • through the pulmonary semilunar valve 
  • pulmonary arteries (right and left) 
  • Lungs (for oxygenation)
98
Q

Blood Flow Through the Heart

slide # 29

A

ORDER:

  • from Pulmonary veins (2 right and 2 left)
  • left atrium 
  • through the bicuspid valve 
  • left ventricle 
  • aortic semilunar valve 
  • aorta 
  • systemic circulation
99
Q

Intrinsic Conduction System of the Heart

A
  • Cardiac muscle is able to initiate its own contraction in a regular way, but its rate is influenced by both intrinsic and extrinsic factors
  • The intrinsic conduction (nodal) system increases the rate of heart contraction and ensures that the heart beats as a unit
100
Q

Intrinsic Conduction System of the Heart

A

Sinoatrial (SA) node is the heart’s pacemaker

Atrioventricular (AV) node is at the junction of the atria and ventricles

Atrioventricular (AV) bundle (bundle of His) is in the interventricular septum

Bundle branches are in the interventricular septum

Purkinje fibers spread within the ventricle wall muscles

101
Q

Sinoatrial (SA) node

A

is the heart’s pacemaker

102
Q

Atrioventricular (AV) node

A

is at the junction of the atria and ventricles

103
Q

Atrioventricular (AV) bundle (bundle of His)

A

is in the interventricular septum

104
Q

Bundle branches

A

are in the interventricular septum

105
Q

Purkinje fibers

A

spread within the ventricle wall muscles

106
Q

Cardiac Innervation

A
  • Autonomic nervous system adjusts HR and force of contraction
  • Cardiac centers in medulla oblongata
  • PNS effects: decreases heart rate
  • SNS effects: increases heart rate and force of contraction
107
Q

Heart Rates

A

Resting heart rate:

  • Varies with age, health, physical conditioning
  • Normal range 60–100 bpm
108
Q

Factors Affecting Heart Rate

A

See Slide # 37 for the Table

109
Q

Electrocardiogram (ECG or EKG) is

A
  • Recording of electrical activity of heart using electrodes on surface of body
  • slide 38
110
Q

Electrocardiogram

A
  • P wave shows depolarization of atria
  • QRS complex shows depolarization of ventricles
  • T wave shows ventricular repolarization
111
Q

Tachycardia –

A

heart rate over 100 beats per minute

112
Q

Bradycardia –

A

heart rate less than 60 beats per minute

113
Q

Cardiac cycle

A

the sequence of events that occurs during a heartbeat - a coordinated contraction and relaxation of chambers of heart

  1. Cardiac cycle begins with all chambers relaxed
    - Ventricles partially filled with blood
  2. Atrial systole
    - Atria contract, filling ventricles
  3. Atrial diastole continues until start of next cardiac cycle
  4. Ventricular systole – first phase
    - AV valves pushed closed by ventricular contraction
    - Semilunar valves still closed
    - Isovolumetric contraction (no change in volume)
  5. Ventricular systole – second phase

-Increasing pressure pushes open
semilunar valves and blood flows out of ventricle

  • Ventricular ejection
    6. Ventricular diastole – early
  • Pressure drops in ventricles
  • Blood flowing back against semilunar valve cusps closes valves
    7. Isovolumetric relaxation
  • Semilunar valves closed; AV valves still closed
  • Blood flowing into atria
  1. Ventricular diastole – late
    - All chambers relaxed
  • AV valves open and ventricles passively fill to 70 percent final volume
  • Ventricular diastole lasts through end of one cardiac cycle and into beginning of next (until next ventricular systole)
114
Q

Two basic phases of cardiac cycle

A
  1. Contraction (systole)
    - Blood pushed into adjacent chamber or arterial trunk
  2. Relaxation (diastole)
    - Chamber fills with blood
115
Q

The Cardiac Cycle

A

Slide 43 and 47 for the table

116
Q

Cardiac Cycle ensure that

A
  • there is adequate blood flow to all body parts
  • Average HR is 70 - 75 beats per minute
  • Cardiac cycle takes about 0.8 seconds to complete
117
Q

If HR is faster than cardiac cycle time:

A

*Diastole shortens – chambers don’t fill completely with blood, so less is pumped out per beat

118
Q

The Heart: Cardiac Output

A

Cardiac output (CO or Q)

Stroke volume (SV)

Heart rate (HR)

119
Q

Regulation of Heart Rate

A
  1. Increased heart rate:
  • Sympathetic nervous system
  • Hormones
  • Exercise
  • Decreased blood volume

2.Decreased heart rate

  • Parasympathetic nervous system
  • High blood pressure or blood volume
  • Decreased venous return
120
Q

Resting HR varies due to

A

size - bigger heart has slower rate

sex - women faster than men

age - young faster than old

exercise (> rate)

fever (> rate)

stimulation of SNS (> rate)

stimulation of PNS (< rate)

hormones (thyroid, epinephrine,

norepinephrine > rate)

121
Q

Stroke Volume (SV)

A
  • volume of blood pumped out of left ventricle per beat  average is ~70 mL/beat
  • At rest ventricles pumps out only about 67% of blood within them (termed ejection fraction)

—More forcefully ventricles contract – more blood is ejected

122
Q

Preload -

A
  • amount of blood in ventricles at the end of diastole (remember that ventricle fills with blood during resting phase of diastole)
  • increased preload stretches ventricles thus increased force of contraction (increased SV and CO)

*decreased preload deceases
stretch in ventricles thus decreased force of contraction (decreased SV and CO)

123
Q

Afterload -

A
  • refers to resistance or opposition
  • In order for left ventricle to pump blood into aorta it must push against blood that is already there
  • The pressure within the aorta is the resistance or afterload
  • A narrow aorta means the left ventricle will need to work harder to overcome resistance
  • Same theory holds true for right ventricle
  • If pulmonary artery is narrowed then right ventricle needs to work hard to pump bld into pulmonary artery
  • Same event occurs – hypertrophy of right ventricle  leading to right-sided heart failure (Cor Pulmonale)
  • Afterload can be altered by drugs
124
Q

Ejection Fraction (EF)

A
  • When ventricle contracts, it pumps about 67% of it’s volume (thus 33% remains in ventricles)
  • Percentage of blood pumped is called the ejection fraction – indicator of cardiac health
  • 90% EF with exercise – healthy heart
  • 30% EF with walking – very poor heart
125
Q

Stroke Volume (SV

A

SV – volume of blood pumped out of left ventricle per beat  average is ~70 mL/beat

*Can change SV by two ways:

  • Starling’s Law
  • Inotropic Effect
126
Q

Starling’s Law of Heart

A

slide 58

127
Q

Inotropic Effect

A
  • Second way of increasing SV is to strengthen the force of contraction without stretching the heart fibers
  • ***done by stimulating sympathetic nerves with hormones and drugs
  • increase SV  Digoxin (+ inotropic effect)

-decrease SV drug  Ca2+ channel
blockers (- inotropic effect

128
Q

Ions

A

***Ions have an effect on HR/contraction

  • Reduced Ca2+ depresses heart rate and contractility
  • Elevated Ca2+ prolongs contractions – heart failure
  • Reduced and elevated K+ causes the heart to beat poorly and irregularly
129
Q

Cardiac Output

A

*Amount of blood pumped by left ventricle in one minute

Depends on:***

  • Heart rate
  • Stroke volume
130
Q

Cardiac Output Adjustment

A

***Body can adjust cardiac output to meet needs

  • Heart rate can increase by 250 percent
  • Stroke volume can double

Anatomy & Physiology 2nd Sem. (5 decks)

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