Circulatory System

Question 1

What is the main function of the heart?

Answer 1

To pump blood throughout the body, supplying oxygen and nutrients while removing waste products.

Question 2

Where is the heart located?

Answer 2

In the mediastinum of the thoracic cavity, between the lungs, slightly left of the midline.

Question 3

What are the three layers of the heart wall?

Answer 3

Epicardium (outer), myocardium (middle, muscular), and endocardium (inner).

Question 4

What is the pericardium?

Answer 4

A double-walled sac that encloses and protects the heart, consisting of fibrous and serous layers.

Question 5

What are the four chambers of the heart?

Answer 5

Right atrium, right ventricle, left atrium, and left ventricle.

Question 6

What is the function of the right atrium?

Answer 6

Receives deoxygenated blood from the body via the superior and inferior vena cava and the coronary sinus.

Question 7

What is the function of the right ventricle?

Answer 7

Pumps deoxygenated blood into the pulmonary trunk toward the lungs.

Question 8

What is the function of the left atrium?

Answer 8

Receives oxygenated blood from the lungs via the pulmonary veins.

Question 9

What is the function of the left ventricle?

Answer 9

Pumps oxygenated blood into the aorta for systemic circulation.

Question 10

Which chamber of the heart has the thickest wall?

Answer 10

The left ventricle, because it must pump blood at high pressure through the systemic circulation.

Question 11

What are auricles?

Answer 11

Small muscular appendages of the atria that increase atrial volume.

Question 12

What are the coronary sulci (grooves)?

Answer 12

External grooves marking the separation between the atria and ventricles (coronary sulcus) and between ventricles (anterior and posterior interventricular sulci).

Question 13

What major vessels are visible on the anterior surface of the heart?

Answer 13

Aorta, pulmonary trunk, superior vena cava, and coronary arteries.

Question 14

What forms the apex of the heart?

Answer 14

The tip of the left ventricle.

Question 15

What forms the base of the heart?

Answer 15

Mainly the posterior surface formed by the left atrium.

Question 16

What structure separates the right and left atria?

Answer 16

The interatrial septum.

Question 17

What structure separates the right and left ventricles?

Answer 17

The interventricular septum.

Question 18

What is the fossa ovalis?

Answer 18

A depression in the interatrial septum, a remnant of the fetal foramen ovale.

Question 19

What are pectinate muscles?

Answer 19

Ridges of muscle found in the atrial walls, especially in the right atrium and auricles.

Question 20

What are trabeculae carneae?

Answer 20

Irregular muscular ridges found on the inner walls of ventricles.

Question 21

What are papillary muscles?

Answer 21

Muscles that anchor chordae tendineae and contract to prevent valve inversion during ventricular contraction.

Question 22

What are chordae tendineae?

Answer 22

Tendinous cords connecting papillary muscles to atrioventricular valve cusps.

Question 23

What are the atrioventricular (AV) valves?

Answer 23

The tricuspid valve (right side) and mitral/bicuspid valve (left side), preventing backflow into atria.

Question 24

What are the semilunar valves?

Answer 24

The pulmonary and aortic valves, preventing backflow into ventricles.

Question 25

Which valve separates the right atrium and right ventricle?

Answer 25

Tricuspid valve.

Question 26

Which valve separates the left atrium and left ventricle?

Answer 26

Mitral (bicuspid) valve.

Question 27

Which valve separates the right ventricle and pulmonary trunk?

Answer 27

Pulmonary semilunar valve.

Question 28

Which valve separates the left ventricle and aorta?

Answer 28

Aortic semilunar valve.

Question 29

Trace the flow of blood through the heart (start with systemic veins).

Answer 29

Systemic veins → Right atrium → Tricuspid valve → Right ventricle → Pulmonary valve → Pulmonary trunk → Lungs → Pulmonary veins → Left atrium → Mitral valve → Left ventricle → Aortic valve → Aorta → Body.

Question 30

Which side of the heart is responsible for pulmonary circulation?

Answer 30

The right side (pumps blood to the lungs).

Question 31

Which side of the heart is responsible for systemic circulation?

Answer 31

The left side (pumps blood to the body).

Question 32

What is the function of the coronary circulation?

Answer 32

To supply oxygen and nutrients to the myocardium.

Question 33

Which arteries supply blood to the heart muscle?

Answer 33

The right and left coronary arteries, originating from the base of the ascending aorta.

Question 34

What are the main branches of the right coronary artery (RCA)?

Answer 34

Right marginal artery and posterior interventricular (posterior descending) artery.

Question 35

What are the main branches of the left coronary artery (LCA)?

Answer 35

Anterior interventricular (left anterior descending, LAD) artery and circumflex artery.

Question 36

What area does the right coronary artery primarily supply?

Answer 36

Right atrium, right ventricle, SA node, and part of the left ventricle.

Question 37

What area does the left coronary artery primarily supply?

Answer 37

Left atrium, left ventricle, and interventricular septum.

Question 38

What is the great cardiac vein?

Answer 38

It runs alongside the anterior interventricular artery and drains the anterior heart into the coronary sinus.

Question 39

What is the middle cardiac vein?

Answer 39

It runs in the posterior interventricular sulcus and drains into the coronary sinus.

Question 40

What is the coronary sinus?

Answer 40

A large venous channel on the posterior heart that collects venous blood from the myocardium and drains into the right atrium.

Question 41

Which vein drains most of the venous blood from the heart?

Answer 41

The coronary sinus.

Question 42

Where do the coronary arteries originate?

Answer 42

From the ascending aorta just above the aortic valve.

Question 43

What prevents blood from flowing backward through the heart?

Answer 43

The heart valves (atrioventricular and semilunar).

Question 44

What ensures one-way flow of blood in the circulatory system?

Answer 44

Valve function and pressure differences between chambers.

Question 45

What happens during systole?

Answer 45

Ventricular contraction and blood ejection from the heart.

Question 46

What happens during diastole?

Answer 46

Ventricular relaxation and filling with blood.

Question 47

What causes the 'lub' sound of the heartbeat?

Answer 47

Closure of the AV valves at the beginning of ventricular systole.

Question 48

What causes the 'dub' sound of the heartbeat?

Answer 48

Closure of the semilunar valves at the beginning of ventricular diastole.