block 2 past papers

Question 1

Name the different layers of the pericardium and their nerve supply. Give the attachment of the outermost layer.

Answer 1

1. Fibrous pericardium (outermost):
   Attachments:
   - inferiorly: fused w/ central tendon of diaphragm
   - anteriorly: posterior surface of sternum
   - superiorly: continuous w/ adventitia of great vessels (aorta, pulmonary trunk, superior vena cava)
2. serous pericardium: 2 layers (parietal & visceral)

nerve supply: fibrous pericardium + parietal layer of serous pericardium are supplied by phrenic nerves

visceral layer of serous pericardium is supplied by autonomic fibers from cardiac plexus

Question 2

explain how a needle can be inserted to aspirate pericardial fluid (paracentesis).

Answer 2

• patient at supine position w/ head elevated ~30º
• needle inserted just left of xiphoid process
• needle inserted at 45º angle, directed upward, backward, & toward left shoulder

Question 3

Give areas of distribution of left coronary artery.

Answer 3

arises from the left aortic sinus of the ascending aorta and quickly divides into two major branches: Left anterior descending (LAD) / anterior interventricular branch &
Circumflex (LCx) branch

areas supplied:
- left atrium
- most of left ventricle
- part of right ventricle
- SA node

Question 4

How will you differentiate a medium sized artery from a medium sized vein histologically?

Answer 4

medium sized artery:
- thicker wall, smaller lumen
- many layers of smooth muscle cells
- internal elastic lamina prominent
- usually round (holds shape)

medium sized vein:
- thin wall, larger lumen
- elastic lamina absent or very thin
- lumen often collapsed or irregular in shape