Pericardium, Heart and Innervation

Question 1

What are the two main layers of the pericardium?

Answer 1

The fibrous pericardium and serous pericardium.

Question 2

What are the two layers of the serous pericardium?

Answer 2

The parietal layer and visceral layer (epicardium).

Question 3

What is the function of the pericardium?

Answer 3

It encloses and protects the heart, prevents excessive dilation, and reduces friction.

Question 4

What structures form the fibrous pericardium?

Answer 4

Dense connective tissue attached to the diaphragm and great vessels.

Question 5

What is the clinical significance of the pericardial cavity?

Answer 5

It contains serous fluid, reducing friction between the pericardial layers.

Question 6

What is cardiac tamponade?

Answer 6

A life-threatening condition where fluid accumulation in the pericardial cavity compresses the heart.

Question 7

What is the arterial supply of the pericardium?

Answer 7

The pericardiacophrenic, musculophrenic, and coronary arteries.

Question 8

What veins drain the pericardium?

Answer 8

The pericardiacophrenic veins, draining into the brachiocephalic veins.

Question 9

What nerves supply the pericardium?

Answer 9

The phrenic nerve (somatic sensation), vagus nerve, and sympathetic trunk.

Question 10

What is the location of the heart in the thoracic cavity?

Answer 10

In the middle mediastinum, posterior to the sternum, between the lungs.

Question 11

What are the borders of the heart?

Answer 11

Right border (right atrium), left border (left ventricle and auricle), inferior border (right ventricle), superior border (atria and great vessels).

Question 12

What are the surfaces of the heart?

Answer 12

Anterior (sternocostal), inferior (diaphragmatic), and posterior (base).

Question 13

What are the chambers of the heart?

Answer 13

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

Question 14

What structure separates the right and left atria?

Answer 14

The interatrial septum.

Question 15

What structure separates the right and left ventricles?

Answer 15

The interventricular septum.

Question 16

What is the function of the right atrium?

Answer 16

It receives deoxygenated blood from the body and pumps it into the right ventricle.

Question 17

What is the function of the left atrium?

Answer 17

It receives oxygenated blood from the lungs and pumps it into the left ventricle.

Question 18

What is the function of the right ventricle?

Answer 18

It pumps deoxygenated blood into the pulmonary circulation via the pulmonary trunk.

Question 19

What is the function of the left ventricle?

Answer 19

It pumps oxygenated blood into the systemic circulation via the aorta.

Question 20

What are the main heart valves?

Answer 20

The tricuspid, pulmonary, mitral, and aortic valves.

Question 21

What is the function of the tricuspid valve?

Answer 21

It prevents backflow of blood from the right ventricle into the right atrium.

Question 22

What is the function of the pulmonary valve?

Answer 22

It prevents backflow from the pulmonary trunk into the right ventricle.

Question 23

What is the function of the mitral valve?

Answer 23

It prevents backflow from the left ventricle into the left atrium.

Question 24

What is the function of the aortic valve?

Answer 24

It prevents backflow from the aorta into the left ventricle.

Question 25

What structures anchor the atrioventricular valves?

Answer 25

Chordae tendineae and papillary muscles.

Question 26

What is the fibrous skeleton of the heart?

Answer 26

A dense connective tissue framework that supports the heart valves and anchors the myocardium.

Question 27

What are the main coronary arteries?

Answer 27

The right and left coronary arteries.

Question 28

What areas of the heart does the right coronary artery supply?

Answer 28

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

Question 29

What areas of the heart does the left coronary artery supply?

Answer 29

The left atrium, left ventricle, and most of the interventricular septum.

Question 30

What are the main cardiac veins?

Answer 30

The great cardiac vein, middle cardiac vein, small cardiac vein, and coronary sinus.

Question 31

What is the function of the coronary sinus?

Answer 31

It collects venous blood from the heart and drains into the right atrium.

Question 32

What is the conducting system of the heart?

Answer 32

The SA node, AV node, AV bundle, right and left bundle branches, and Purkinje fibers.

Question 33

What is the function of the sinoatrial (SA) node?

Answer 33

It acts as the pacemaker, initiating the heartbeat.

Question 34

What is the function of the atrioventricular (AV) node?

Answer 34

It delays electrical impulses to allow atrial contraction before ventricular contraction.

Question 35

What is the function of the atrioventricular bundle (Bundle of His)?

Answer 35

It transmits impulses from the AV node to the ventricles.

Question 36

What is the function of the Purkinje fibers?

Answer 36

They distribute impulses rapidly to the ventricular myocardium, ensuring synchronized contraction.

Question 37

What is the autonomic innervation of the heart?

Answer 37

The heart is innervated by the cardiac plexus, receiving sympathetic and parasympathetic fibers.

Question 38

What is the effect of sympathetic stimulation on the heart?

Answer 38

Sympathetic stimulation increases heart rate and force of contraction.

Question 39

What is the effect of parasympathetic stimulation on the heart?

Answer 39

Parasympathetic stimulation decreases heart rate and force of contraction.

Question 40

What is the clinical significance of the cardiac plexus?

Answer 40

It coordinates autonomic control of heart rate and force of contraction.

Question 41

What are the major branches of the right coronary artery?

Answer 41

The sinoatrial nodal artery, right marginal artery, posterior interventricular artery.

Question 42

What are the major branches of the left coronary artery?

Answer 42

The anterior interventricular artery (LAD) and circumflex artery.

Question 43

What is the anatomical basis of referred cardiac pain?

Answer 43

Cardiac pain is referred to the left arm, shoulder, neck, and jaw due to shared spinal segments (T1-T4).

Question 44

What is the blood supply of the interventricular septum?

Answer 44

The anterior two-thirds is supplied by the LAD, and the posterior one-third by the posterior interventricular artery.

Question 45

What are the three layers of the heart wall?

Answer 45

Endocardium, myocardium, and epicardium.

Question 46

What is the role of the endocardium?

Answer 46

It lines the heart chambers and valves, providing a smooth surface for blood flow.

Question 47

What is the role of the myocardium?

Answer 47

It contains cardiac muscle, responsible for contraction and blood ejection.

Question 48

What is the role of the epicardium?

Answer 48

It is the outermost layer, consisting of visceral pericardium and fat.

Question 49

What is the embryological origin of the heart?

Answer 49

The heart develops from the mesodermal cardiogenic plate.

Question 50

What is the clinical significance of the transverse pericardial sinus?

Answer 50

It allows surgical clamping of the aorta and pulmonary trunk during procedures like cardiopulmonary bypass.