Chapter 18

Question 1

Apex of Heart

Answer 1

inferior end formed by left ventricle

Question 2

Base of Heart

Answer 2

Is superior/posterior portion formed by the atria; points to right shoulder

Question 3

Pericardium Main Functions

Answer 3

1) Protects and anchors heart 2) Prevents heart from overfilling with blood 3) Allows the heart to work in a relatively friction free environment.

Question 4

Coverings of the Heart (4)

Answer 4

1) Fibrous pericardium 2) Parietal Pericardium 3) Pericardial Cavity 4) Visceral / Epicardium

Question 5

List the three layers of the heart wall

Answer 5

1) Epicardium (visceral pericardium) outer layer
2) Myocardium: cardiac muscle, bulk of the heart
3) Endocardium: endothelial layer of the inner myocardial surface

Question 6

Where is the right ventricle located

Answer 6

(looking at piece of paper straight on) its on the left bottom side of the heart.

Question 7

Where is the right Atrium

Answer 7

on the left upper side of heart

Question 8

Where is the left ventricle/ atrium

Answer 8

ventricle = right, lower side of heart, 
atrium = right upper side of heart

Question 9

Define Sulci (sulcus)

Answer 9

Groove on the surface of the heart

Question 10

Define Coronary Sulcus

Answer 10

a depression surrounding the heart at the atrioventricular junction and giving passage to coronary arteries, coronary veins, and the coronary sinus.

Question 11

Define Anterior Interventricular Sulcus

Answer 11

shallow groove between left and right ventricles on anterior surface (over septum)

Question 12

Define Posterior Interentricular sulcus

Answer 12

siilar landmark but on the posteroinferior surface

Question 13

Name the two vessels returning blood to the heart

Answer 13

Superior/ Inferior Venae cavae, Right/Left pulmonary veins

Question 14

Name the two vessels conveying blood away from the heart

Answer 14

Pulmonary Trunk (left/right pulmonary arteries) 
Ascending aorta ( Brachiocephalic, left common, left subclavian arteries)

Question 15

Compare the Atrias’ of the heart to the ventricles

Answer 15

-Atrias are the receiving chambers, and ventricles are the discharging chambers

Question 16

What is a pectinate muscle

Answer 16

a combed muscle in the atrial walls

Question 17

what three veins give blood to the right atrium

Answer 17

1) superior venae cavae (drains body superior to diaphragm)
2) Inferior venae cavae (drains body inferior from diaphragm)
3) Coronary sinus (drains myocardium) (is a vein attached to heart)

Question 18

Where do the 4 pulmonary veins drain their blood to

Answer 18

the Left atrium

Question 19

Describe Ventricles

Answer 19

pump blood away from the heart

Question 20

where and what do papillary muscles and trabecular carneae muscles do

Answer 20

they mark the ventricular walls and prevent Artrioventricular valves from everting (going in or out on themselves)

Question 21

which ventricle pumps blood into the pulmonary trunk

Answer 21

Right ventricle

Question 22

where does the left ventricle pump blood to

Answer 22

the aorta

Question 23

What is the function of heart valves

Answer 23

ensure unidirectional blood flow

Question 24

Antrioventricular (AV)

Answer 24

prevents back flow from ventricles to atria
Right side = tricuspid
Left side = Mitral valvue (bicuspid)

Question 25

Chordae Tendineae

Answer 25

Anchores AV valves to papillary muscles

Question 26

Where do the two semilunar vales flow to and from

Answer 26

1) aortic semilunar: from left ventricle to aorta | 2) pulmonary semilunar: from right ventricle to pulmonary trunk

Question 27

how many nuclei can a heart muscle have

Answer 27

one or two

Question 28

how do heart muscles behave

Answer 28

as a single coordinated unit (functional syncytium)

Question 29

How does a heart muscle contract

Answer 29

1) stimulated by nerves | 2) self-excitable (autorythmic: generates its own rhythmic action potentials independent of the nervous system).

Question 30

Describe the function of Senatorial Nodes

Answer 30

a small group of cells in the walls of the right atrium that control the rhythmic beating of the heart. (SA nodes)

Question 31

Does the heart have a long or short refractory period

Answer 31

A long one. (becomes unresponsive to further stimuli after a stimulation)

Question 32

Briefly describe the 3 phases of action potentials in the cardiac muscle cells

Answer 32

1) Depolarization: na+ influx through fast na+ voltage gated channels. Channel inactivation ends this phase 2) Plateau Phase: due to Ca2+ influx through slow Ca2+ channels. this keeps the cell depolarized because few K+ channels are open 3) Repolarization: due to Ca2+ channels inactivating and K+ channels opening. allows K+ efflux, which brings the membrane potential back to its resting voltage.

Question 33

Does nervous input modify cardiac conduction

Answer 33

Yes, but cardiac muscles can initiate action potentials on their own

Question 34

what cells can depolarize spontaneously

Answer 34

pacemaker cells, (unstable resting potentials = pacemaker potentials)

Question 35

what does calcium influx represent

Answer 35

the rising phase of the action potentials in the cardiac system

Question 36

Where does Purkinje Finbers carry an impulse to

Answer 36

the heart apex and ventricular walls

Question 37

Where do bundle branches carry an impulse to

Answer 37

the apex of the heart

Question 38

what does p wave correspond to

Answer 38

depolarization of SA nodes

Question 39

QRS complex corresponds to

Answer 39

ventricular depolarization

Question 40

T wave corresponds to

Answer 40

ventricular depolarization

Question 41

Lub Lub =

Answer 41

closing of the heart

Question 42

sounds occur when

Answer 42

1) AV valves close | 2) SL valves close

Question 43

What does a cardiac cycle refer to

Answer 43

all events associated with blood flow through the hear

Question 44

Systole =

Answer 44

contraction of heart muscle

Question 45

Diastole =

Answer 45

relaxation of heart muscle

Question 46

What does cardiac output mean

Answer 46

the amount of blood pumped by each ventricle in one minute

Question 47

CO is the product of what

Answer 47

Heart reate (HR) and stroke volume (SV)