Chapter 20: The Heart

Question 1

Located in mediastinum. Average is 70bpm

Answer 1

Heart

Question 2

Walls of the ______ ventricle or thicker than the _______ side

Answer 2

Left, right

Question 3

The heart is surrounded by the ________ cavity which is lined by the pericardium.

Answer 3

pericardial

Question 4

The _______ pericardium covers outer surface of heart.

Answer 4

Visceral pericardium (epicardium)

Question 5

Middle layer of heart, Cardiac muscle, coronary blood vessels.

Answer 5

Myocardium

Question 6

Lines inner layer of heart. Endothelium.

Answer 6

Endocardium

Question 7

Valves that prevent backflow of blood. Separate the atria from the ventricles. Chordae tendinae and papillary muscles.

Answer 7

Atrioventricular Valves

Question 8

Dense connective tissue. Prevents over stretching of valves. Electrical insulator between atria and ventricles

Answer 8

Fibrous Skeleton

Question 9

Vessels that branch from ascending aorta. Supply heart muscle with oxygen and nutrients and remove waste products

Answer 9

Coronary Vessels

Question 10

The right side of the heart is the ______ circuit.

Answer 10

Pulmonary Circuit

Question 11

The left side of the heart is the ________ circuit.

Answer 11

Systemic Circuit

Question 12

“Pacemaker cells tell all the other cells what to do. In right atrium

Answer 12

Sinoatrial node (SA node)

Question 13

On right atrium floor. Relay the contractile stimulus to bundle of His, the bundle branches, Purkinje fibers, and ventricular myocardium

Answer 13

Atrioventricular node (AVnode)

Question 14

The pulmonary veins carry ______ blood to the ______ atrium.

Answer 14

oxygenated, left

Question 15

Cardiac veins empty their blood into the __________ atrium.

Answer 15

right atrium

Question 16

The epicardium is also known as the __________ pericardium.

Answer 16

visceral pericardium

Question 17

Which part of the conduction system initiates the depolarizing impulse, which spreads throughout the heart?

Answer 17

SA node

Question 18

What does the ECG wave tracing ?

Answer 18

electrical activity in the heart

Question 19

What does the QRS complex represent in the ECG wave tracing?

Answer 19

ventricular depolarization

Question 20

Which part of the intrinsic conduction system delays the impulse briefly before it moves on to the ventricles?

Answer 20

AV node

Question 21

ear-like extension of the atrium

Answer 21

auricle

Question 22

The __________ valve prevents backward flow of blood into the left ventricle.

Answer 22

aortic

Question 23

Action potentials generated by the autorhythmic cells spread to the contractile cells through what structures in the membrane?

Answer 23

gap junctions

Question 24

One of the changes that occurs in the pacemaker potential (unstable resting membrane potential) in the SA node (an autorhythmic cell) is a decreased efflux of what ion?

Answer 24

potassium

Question 25

When threshold is reached at the SA node (an autorhythmic cell), what channels open causing further depolarization of the membrane?

Answer 25

fast calcium

Question 26

Heart rate is controlled by __________ vagus and __________ nerves.

Answer 26

right vagus and sympathetic nerves

Question 27

During the plateau phase of the cardiac action potential, which ion is entering the cardiac muscle cell?

Answer 27

calcium

Question 28

Blood is supplied to the myocardium by _______ arteries.

Answer 28

coronary arteries

Question 29

What’s the order of cardiac excitation?

Answer 29

1. SA node
2. AV mode
3. Bundle of HIS
4. Bundle branches
5. Purkinje Fibers

Question 30

The Frank Starling law

Answer 30

The more the heart stretches, the harder it will contract, forcing more blood out.

Question 31

The foramen ovale in the fetal heart is located in the __________

Answer 31

interatrial septum

Question 32

Increased pressure in the ventricles would close what valve(s)?

Answer 32

AV valves only

Question 33

Ventricular systole begins with the closing of the ______ valve.

Answer 33

mitral valve

Question 34

With each ventricular systole, blood pressure _________

Answer 34

increases

Question 35

Simulation of the vagus nerve will _______ cardiac output.

Answer 35

decrease

Question 36

Intrinsic factors influence ______ output.

Answer 36

cardiac

Question 37

Frank starling regulates _____ volume.

Answer 37

stroke

Question 38

Stimulation of SNS will ________ stroke volume and heart rate.

Answer 38

increase

Question 39

Stimulation of the PNS will _______ heart rate by releasing acetylcholine which opens chemically gated ___ channels and allows an efflux of ___.

Answer 39

decrease

K+

Question 40

Rapid depolarization in cardiac muscle when at threshold, voltage gated ___ channels open and cause an influx.

Answer 40

Na+

Question 41

The Plateau phase of action potential in cardiac muscle:

When potential reaches +30mV, voltage gated ___ channels close and inactivated until potential drops to -60mV.
Na+ are then pumped out the cell and voltage gated ___ channels are opened.
Loss of Na+ and gain of Ca+ causes potential to remain at 0.

Answer 41

Na+

Ca+

Question 42

Repolarization period in cardiac muscle:

Slow Ca+ channels close and slow ___ open to cause efflux of ___.

Answer 42

K+

Question 43

EDV-ESV=___

Answer 43

SV

Question 44

Preload is the degree of ________ in ventricles during ventricular diastole.

Answer 44

stretching

Question 45

Afterload is the amount of tension that the ventricles must produce to force open the _________ valve and eject blood.

Answer 45

semilunar

Question 46

Afterload _______ with increased resistance to blood flow out of ventricle, which _______ stroke volume.

Answer 46

increases

decreases

Question 47

3 layers of pericardium include visceral (epicardium), parietal, and _______.

Answer 47

fibrous