Heart

Question 1

The _____ of the heart is the widest part; the _____ is the narrow end, which points toward the left hip.

Answer 1

Base; Apex

Question 2

The muscular wall of the heart (which accounts for most of the heart’s mass) is called the _____.

Answer 2

Myocardium

Question 3

The central layer of the heart’s wall is called the _____.

Answer 3

myocardium

Question 4

The two uppermost chambers of the heart are the _____.

Answer 4

atria

Question 5

The two lowermost chambers of the heart are the _____.

Answer 5

ventricles

Question 6

The partition that separates the left and right chambers of the heart is called the _____. The upper part is the _____, and the lower part is the _____.

Answer 6

septum; interatrial septum; interventricular septum

Question 7

The shallow groove separating the atria from the ventricles is called the _____ or _____.

Answer 7

atrioventricular groove; coronary sulcus

Question 8

The purpose of the muscular wall of each _____ is simply to pump blood from one chamber to the next, and so not much muscle is required.

Answer 8

atrium

Question 9

Blood has to travel further in the _____ circuit than in the _____ circuit: therefore there is more friction, and more strength is required to keep it moving.

Answer 9

systemic; pulmonary

Question 10

After passing through the capillary beds of the myocardium, venous blood is collected in the _____.

Answer 10

cardiac veins

Question 11

In almost half of the population, the SA node is supplied with blood by the _____.

Answer 11

circumflex artery

Question 12

The right atrium, AV node, and nearly all of the right ventricle are usually supplied by the _____.

Answer 12

right main coronary artery

Question 13

Most veins of the heart join together to form a large vessel called the _____, which is most visible on the _____ aspect of the heart.

Answer 13

coronary sinus; posterior

Question 14

The _____ and _____ valves prevent backflow into the atria when the ventricles contract: together these are called the _____ valves.

Answer 14

tricuspid; bicuspid; atrioventricular (AV)

Question 15

The _____ AV valve is the tricuspid valve.

Answer 15

right

Question 16

The _____ AV valve is the bicuspid (or ‘mitral’) valve.

Answer 16

left

Question 17

The AV valves are closed by the _____.

Answer 17

intraventricular pressure

Question 18

(True or False) There are no valves preventing backflow of blood from the heart into the veins which deliver blood to it from the body and lungs.

Answer 18

TRUE

Question 19

(True or False) Atrial contraction nearly closes the openings through which blood enters the heart.

Answer 19

TRUE

Question 20

(True or False) Cardiac muscle is capable of switching nutrient pathways to use whatever nutrient supply is available.

Answer 20

TRUE

Question 21

(True or False) The sarcomeres of cardiac muscle fibers have terminal cisternae at each end.

Answer 21

False

Question 22

The _____ is the cluster of autorhythmic cells in the heart which spontaneously depolarize the fastest and thus is known as the heart’s _____.

Answer 22

SA node; pacemaker

Question 23

When clusters of cardiac fibers contract independently, producing rapid and irregular or out-of-phase contractions, the condition is called _____.

Answer 23

fibrillation

Question 24

Uncoordinated atrial and ventricular contractions are referred to as _____.

Answer 24

arrhythmias

Question 25

The _____ is the highest, strongest peak on a normal ECG together with the downward deflections that immediately precede and follow it.

Answer 25

QRS complex

Question 26

After a brief delay, a third peak follows the first two. This third peak is called the _____ and is due to _____.

Answer 26

T wave; ventricular repolarization

Question 27

A(n) _____ on an ECG is occasionally not followed by a(n) _____; this indicates a heart block.

Answer 27

P wave; QRS complex

Question 28

The volume of blood contained by the ventricles at the end of an atrial contraction is known as the _____. This term is based on the contents of the _____.

Answer 28

end diastolic volume (EDV); ventricles

Question 29

During ventricular contraction, the period during which all valves are closed is the _____.

Answer 29

isovolumetric contraction phase

Question 30

The _____ is the period during which both the atria and ventricles relax.

Answer 30

quiescent period

Question 31

_____ is the volume of blood remaining in the ventricle when the SL valves close at the end of ventricular systole.

Answer 31

Ending systolic volume (ESV)

Question 32

An average adult’s stroke volume is _____.

Answer 32

70 ml / beat

Question 33

_____ is a heart rate of more than 100 beats per minute.

Answer 33

Tachycardia