Cardio A&P review

Question 1

Venous blood from IVC and
SVC passively empties into
the ______

Answer 1

right atrium

Question 2

During diastole (relaxation of the ventricles) blood flows through the right atrium,
through the _____ valve, and into the right ventricle

Answer 2

right atrioventricular

Question 3

When the right ventricle contracts, venous
blood is pushed through the _____ into the pulmonary artery

Answer 3

pulmonary valve

Question 4

This contraction provides the pressure
that sustains pulmonary blood flow for
ventilation and diffusion

Answer 4

Right ventricle contraction

Question 5

Considered the “workhorse”, the _____ sustains the systemic blood pressure.

Answer 5

left ventricle

Question 5

The serous pericardium is further
divided into two layers

Answer 5

■ Parietal Layer
■ Visceral Layer

Question 5

Cardiac Cell membranes are fused with each other at _____

Answer 5

the intercalated discs and function as communicating gap junctions between cells

Question 6

Between the visceral and parietal layers, there is a potential space called the _____

Answer 6

Pericardial Cavity

Question 6

Two main types of cardiac muscle
fibers exist in the heart

Answer 6

○ Excitatory fibers: conduct electrical
current through the tissue of the heart
○ Contractile fibers

Question 7

What does it mean that cardiac muscle is a syncytium?

Answer 7

cardiac cells are so
interconnected that when one cell
becomes excited, the action potential
rapidly spreads to all of them

Question 8

Removal of calcium leads to _____

Answer 8

the relaxation of the muscle (bradycardia)

Question 9

There is an important difference in the action potentials recorded in cardiac
muscle cells compared to skeletal muscle cells, what is it?

Answer 9

Cardiac action potentials include a Plateau: This plateau in cardiac depolarization causes
ventricular contraction to last as much as 15
times longer than skeletal muscle
contractions from a single action potential.

Question 10

In cardiac cells, the same rapid sodium and potassium channels still exist. However, the presence of______ is mostly
responsible for the difference in action potential tracings

Answer 10

a special L-Type Calcium Channel

Question 11

T/F L-Type calcium/sodium channels are faster than voltage gated sodium channels

Answer 11

F- L-Type Calcium Channels (also known as Slow Calcium Channels and
Calcium-Sodium Channels) are found in the cell membrane and open rather
slowly (compared to voltage-gated Sodium channels) and remain open
much longer

Question 12

The cardiac events that occur from the
beginning of one heartbeat to the beginning
of the next beat = ______

Answer 12

“The Cardiac Cycle.”

Question 13

The first phase of the cardiac cycle is ______

Answer 13

diastole

Question 14

Ends with atrial contraction- the “Kick.”

Answer 14

Diastole

Question 15

The pulmonary and
aortic valves are
made of _____

Answer 15

sturdy cusps (leaflets)

Question 16

During diastole, the pulmonary and aortic valves are _____

Answer 16

closed (dub)

Question 17

During systole, the AV valves are _____

Answer 17

closed (lub)

Question 18

During systole, the pulmonary and aortic valves are _____

Answer 18

open

Question 19

______ is the single largest killer of all people
in the United States.

Answer 19

Coronary artery atherosclerosis

Question 20

This allows for entry of LDL
cholesterol into the tunica intima

Answer 20

microinflammation or damage to
the intima of the arterial wall.

Question 21

The earliest pathologic lesion of atherosclerosis

Answer 21

“fatty streaks” of LDL cholesterol in the tunica media

Question 22

The presence of serum lipoproteins in the tunica intima triggers the ______

Answer 22

gathering of Monocytes (which become tissue macrophages), which phagocytize the LDL cholesterol, becoming “Foam Cells.”

Question 23

Plaques, also called Atheromas, characteristically occur in regions of ______

Answer 23

branching and/or marked curvature (velocity and direction change)

Question 24

What happens when a placque becomes unstable?

Answer 24

The fibrous cap can rupture, exposing thrombogenic contents to the blood. This results in thrombus formation, partial or complete occlusion of the vessel, and further progression and growth of the atheroma

Question 25

_____ is the main event that causes acute presentation of coronary syndromes

Answer 25

Plaque rupture

Question 26

By impairing or obstructing normal blood flow, atherosclerotic buildup causes ______

Answer 26

myocardial ischemia or infarction

Question 27

When functioning normally, the atrial contraction (kick) occurs about ____ before the strong ventricular contraction

Answer 27

1/6 of a second

Question 28

The _____ is responsible for generating the normal rhythmical impulses for the system

Answer 28

Sinoatrial Node (AKA Sinus Node or SA Node)

Question 29

What does it mean that the Cells of the SA node are “less negative” at rest than the hyperpolarized muscle cells throughout the heart?

Answer 29

○ Specialized L-type Channels are slowly leaking channels that allow for the slow influx of Sodium and Calcium into the cell. ○ This slowly pushes the potential to the threshold for discharge, which is the mechanism by which these cells are capable of self-excitation

Question 30

Total delay of the AV node and why this is important?

Answer 30

total delay of 0.12-0.13 s) ○ This slowing of the impulse through the AV node occurs due to a lower numbers of gap junctions between the excitable cells.

Question 31

T/F The cardiac impulses can move backward from the ventricles to the atria

Answer 31

F

Question 32

the atrial muscle is separated from the ventricular muscle by ____

Answer 32

a continuous fibrous barrier that acts as an insulator to prevent the passage of impulses other than through the AV bundle.

Question 33

two branches of Purkinje fibers are

Answer 33

○ The Left Bundle Branch ultimately depolarizes the left ventricle. ○ The Right Bundle Branch ultimately depolarizes the right ventricle.

Question 34

T/F The AV Node and Purkinje fibers are able to self-excite if not stimulated by the SA node

Answer 34

T

Question 35

Rhythmic rate of AV node is about _____

Answer 35

40-60 bpm (Purkinje- 15-40 bpm).

Question 36

SA node is the normal pacemaker because its rate is _____

Answer 36

70-80 bpm

Question 37

_____ are pacemakers somewhere other than the SA node.

Answer 37

Ectopic Pacemakers

Question 38

Ectopic pacers result in ____

Answer 38

an abnormal sequence of muscle contraction in the heart (ex: A-fib)

Question 39

How does an EKG work?

Answer 39

● When the cardiac impulse travels through the heart, electrical current also spreads from the heart into the adjacent tissue just enough that we can trace it from the surface. ● Electrodes placed on the skin can measure this changing electrical current.

Question 40

The P wave

Answer 40

Caused by electrical potentials generated during atrial depolarization

Question 41

The QRS Complex

Answer 41

Caused by potentials generated with ventricular depolarization

Question 42

The T wave

Answer 42

Caused by potentials generated during ventricular REpolarization

Question 43

Time from when the SA node first fires until the Purkinje fibers fire (about 0.15-0.16 seconds). The delay caused by the AV node

Answer 43

PR Interval

Question 44

Essentially the time between each impulse (tells us the HR).

Answer 44

RR Interval

Question 45

The length of time the ventricle muscle cells are depolarized

Answer 45

QT Interval

Question 46

The time between ventricular depolarization and repolarization.

Answer 46

ST Segment

Question 47

As the ventricles contract, this causes a rapid _____ in the intraventricular pressure

Answer 47

increase

Question 48

As intraventricular pressure exceeds the intra- atrial pressure, what happens?

Answer 48

the pressure exceeds pulmonary artery pressure, and aortic (systolic) pressure, the AV valves are pushed closed and the aortic and pulmonic valves are pushed open.

Question 49

About ____% of the End-Diastolic Volume is ejected during Ventricular Ejection

Answer 49

60

Question 50

The fraction of the End-Diastolic Volume that is ejected is called the _____

Answer 50

Ejection Fraction

Question 51

The actual volume of blood that is ejected during ventricular contraction is called

Answer 51

the Stroke Output Volume (stroke volume)

Question 52

The degree of tension on the muscle walls of the ventricles when they begin to contract

Answer 52

Preload

Question 53

The load or pressure against which the ventricles (especially the left ventricle) exert their contractile force and must overcome in order to eject the stroke volume

Answer 53

Afterload

Question 54

Essentially the pressure in the aorta

Answer 54

The systolic blood pressure

Question 55

Frank-Starling Mechanism says that

Answer 55

The greater the heart muscle is stretched during filling, the greater the force and volume of contraction

Question 56

What causes the atrial kick/increased preload?

Answer 56

When an extra amount of blood flows into the ventricles, the cardiac muscle is stretched to a greater length

Question 57

_____ is the amount of blood (the volume) that the heart ejects with each ventricular contraction.

Answer 57

Stroke volume

Question 58

What factors can affect the rate at which the heart beats?

Answer 58

○ Increase (Positive chronotrope)- ■ Sympathetic input (endogenous/exogenous) ■ Hormones, such as thyroid hormone ○ Decrease (Negative chronotrope)- ■ Parasympathetic input

Question 59

Total Peripheral Resistance is a product of three factors:

Answer 59

○ Blood Viscosity- The higher the viscosity, the higher the resistance ○ Total Blood Vessel Length - Which is always a constant... ○ Vessel Diameter (the main factor)

Question 60

Cardiac Output (CO) is the product of

Answer 60

Heart Rate and Stroke Volume ○ In other words, CO = HR x SV

Question 61

four main factors that affect the CO:

Answer 61

○ Heart Rate ○ Contractility ○ Preload ○ Afterload

Question 62

For the most part, increased ____ will increase the CO too, but only to a certain extent

Answer 62

HR

Question 63

Rapid monitoring of CO

Answer 63

■ Neural control of vessel diameter, heart rate, stroke volume

Question 64

Intermediate to long-term monitoring of CO

Answer 64

■ Renin-Angiotensin II system ■ Renin-Aldosterone system ■ Antidiuretic Hormone (ADH)

Question 65

Parasympathetic stimulation of the heart can _____ the CO by as much as 20-30%.

Answer 65

decrease

Question 66

This Baroreceptor Reflex results in _____

Answer 66

decreased blood pressure by decreasing sympathetic outflow and increasing parasympathetic outflow from the CNS.

Question 67

Cells that are sensitive to low oxygen, carbon dioxide excess, and H+ excess are located in chemoreceptor organs at the carotid and aorta

Answer 67

chemoreceptors

Question 68

Review the RAAS system at the end of the slides

Answer 68

:)

Question 69

act as “control conduits” through which blood is released into the capillaries at a rate that meets the needs of that tissue.

Answer 69

Arterioles

Question 70

This blood pressure progressively falls throughout systemic circulation and is about _____ by the time the blood re-enters the right atrium

Answer 70

0 mmHg

Question 71

By far, the ____ are the most distensible of the vasculature, making the ____ a great reservoir for extra blood when needed

Answer 71

veins; veins

Question 72

What is Delayed Compliance?

Answer 72

When a large amount of fluid is added to a vein, there is a sudden increase in pressure due to the elasticity of the vein. However, the vein then immediately starts adjusting to the new volume by relaxing.

Question 73

the pressure in the right atrium is called the _____

Answer 73

Central Venous Pressure