Chap 20

Question 1

What are the upper chambers of the heart called?

Answer 1

Atria

The right atrium receives blood from systemic veins, while the left atrium receives blood from pulmonary veins.

Question 2

What are the lower chambers of the heart responsible for?

Answer 2

Pumping blood

The right ventricle pumps blood to the pulmonary trunk, and the left ventricle pumps blood to the aorta.

Question 3

What is the apex of the heart?

Answer 3

Inferior tip of the heart

The apex rests on the diaphragm.

Question 4

What is the inner serous membrane of the pericardium called?

Answer 4

Visceral pericardium (epicardium)

It covers the heart surface.

Question 5

What is the outer layer of the pericardium called?

Answer 5

Parietal pericardium

It lines the pericardial sac.

Question 6

What are the three layers of the heart?

Answer 6

• Epicardium (visceral pericardium)
• Myocardium
• Endocardium

Epicardium is the outer protective layer, myocardium is the muscular middle layer that contracts to pump blood, and endocardium is the inner lining that reduces friction for blood flow.

Question 7

What does the right atrium do?

Answer 7

Receives blood from superior/inferior vena cava and coronary sinus.

Question 8

What is the function of the left ventricle?

Answer 8

Pumps blood to the aorta

It has the strongest and thickest myocardium.

Question 9

Where is the right AV valve located?

Answer 9

Between right atrium and ventricle

Also known as the tricuspid valve.

Question 10

What is the left AV valve also known as?

Answer 10

Bicuspid or mitral valve

It is located between the left atrium and ventricle.

Question 11

What does the pulmonary semilunar valve do?

Answer 11

Located between right ventricle and pulmonary trunk.
Allows blood to be pump Forward into the atteries, prevents backflow into ventricles

Question 12

What provides structural support for the heart’s valves and chambers?

Answer 12

Fibrous skeleton of the heart.

Question 13

What is the pathway of pulmonary circulation?

Answer 13

Right ventricle - Pulmonary trunk - Lungs - Pulmonary veins - Left atrium.

Question 14

What is the pathway of systemic circulation?

Answer 14

Left ventricle - Aorta - Body - Vena cava - Right atrium.

Question 15

Where do coronary arteries originate from?

Answer 15

Ascending aorta

They supply oxygenated blood to the heart muscle.

Question 16

What is the function of the SA node?

Answer 16

Pacemaker; initiates heartbeat.

Question 17

What does the AV node do?

Answer 17

Delays signal for ventricular filling.

Question 18

What is the sequence of the cardiac conduction system?

Answer 18

SA node - Atrial muscle fibers - AV node - AV bundle (Bundle of His) - Right & left bundle branches - Purkinje fibers - Ventricular muscle fibers.

Question 19

What is the role of gap junctions in cardiac muscle?

Answer 19

Allow rapid electrical conduction for synchronized contractions.

Question 20

What does the P wave in an ECG represent?

Answer 20

Atrial depolarization.

Question 21

What does the QRS complex in an ECG indicate?

Answer 21

Ventricular depolarization (and atrial repolarization).

Question 22

What is represented by the T wave in an ECG?

Answer 22

Ventricular repolarization.

Question 23

What is the purpose of the refractory period in cardiac muscle?

Answer 23

Prevents tetanic contractions, ensuring proper relaxation and filling.

Question 24

Question 25

outer protective layer is the
muscular middle layer that contracts to pump blood is the
inner lining that reduces friction for blood flow is

Answer 25

Epicardium
Myocardium
Endocardium