Heart Anatomy

Question 1

What are the two layers of pericardium?

Answer 1

Fibrous pericardium

Serous pericardium: divided into parietal and visceral layers.

Question 2

What chamber forms the apex of the heart? Where can the apex beat normally be palpated?

Answer 2

The left ventricle forms the apex of the heart. It is normally palpated in the 5th intercostal space in the midclavicular line.

Question 3

Describe the blood supply to the heart.

Answer 3

Blood to the heart arises from the right and left coronary arteries.
Right coronary artery arises from the right aortic sinus and gives off (1) sinu-atrial node branch; (2) right marginal branch; (3) posterior interventricular branch. Then anastomoses posteriorly with the circumflex branch of the left coronary artery.
Left coronary artery arises from the left aortic sinus –> divides into (1) left anterior descending artery and (2) left circumflex artery.

Question 4

What is the venous drainage of the heart?

Answer 4

Blood from the heart flows into the coronary sinus located in the posterior coronary sulcus, which drains into the right atrium.
The major veins that drain the heart are:
(1) Great cardiac vein - begins at the apex and runs in the anterior interventricular sulcus.
(2) Middle cardiac vein - begins at the apex and runs in the posterior interventricular sulcus.
(3) Small cardiac vein - runs with the right marginal artery.
(4) Posterior cardiac vein - lies on the posterior surface of the left ventricle.

Question 5

What is the parasympathetic innervation of the heart?

Answer 5

From the vagus nerve.

Question 6

What is the sympathetic innervation of the heart?

Answer 6

From the sympathetic trunk - T1-T4/5.

Question 7

Explain the afferents of the heart. What do they carry?

Answer 7

Visceral afferents pass with the sympathetic and parasympathetic fibres. Afferents that carry information about blood pressure and blood chemistry pass with the vagus nerve. Afferents that carry information about pain pass with the sympathetic fibres.

Question 8

What veins join to form the SVC?

Answer 8

Right and left brachiocephalic veins

Question 9

What arteries arise from the arch of the aorta?

Answer 9

(1) Brachiocephalic trunk (divides into right common carotid and right subclavian arteries)
(2) Left common carotid artery
(3) Left subclavian artery

Question 10

What 3 changes occur in the heart/blood vessels at birth?

Answer 10

Closure of the ductus venosus
Closure of the ductus arteriosus
Closure of the foramen ovale