HIST Heart & Vessels

Question 1

1. Which of the following is incorrect?
   a) Elastic arteries’ Tunica Media contain elastic lamellae
   b) Both muscular and elastic arteries contain a tunica adventitia layer thinner than their tunica intermedia’s
   c) Muscular arteries’ Tunica Intima contain numerous smooth muscle cells
   d) Muscular arteries’ Tunica Intima contain an internal elastic membrane

Answer 1

Incorrect: c) Muscular arteries’ Tunica Intima contain numerous smooth muscle cells.

For both elastic and muscular arteries, the tunica intima contains few smooth muscle cells.

Question 2

2. Differentiate an elastic artery from a muscular artery.

Answer 2

• Size: Elastic >10mm, Muscular 2-10mm
• T. Intima: muscular artery has internal elastic membrane
• T. Media: elastic artery has elastic lamella
• Examples:
  
  • Elastic: Aorta, brachiocephalic, common carotid
  • Muscular: Brachial, radial, femoral

Question 3

3. Differentiate a large vein from a medium vein.

Answer 3

• T. Intima: medium vein may have an internal elastic membrane
  
  • both will have endothelium, CT and few smooth muscle cells
• T. Media: large vein will have 3-15 layers of smooth muscle
  
  • medium vein will also have smooth muscle but to a lesser extent
  • both will have collagen fibres
    ​
• T. Adventitia: large vein will have longitudinal smooth muscle cells
  
  • both will have CT and will be thicker than t. media

Question 4

4. How does the tunica adventitia differ between arteries and veins?
   a) in veins it is thicker than the t. media, whereas in arteries it is thinner than the t. media
   b) t. adventitia contains connective tissue in veins and not in arteries
   c) t. adventitia contains elastic lamellae in arteries and many layers of smooth muscle in veins
   d) none of the above are correct

Answer 4

correct: a) in veins it is thicker than the t. media, whereas in arteries it is thinner than the t. media

incorrect:

b) t. adventitia contains connective tissue in both veins and arteries
c) t. media contains elastic lamellae in elastic arteries (not in muscular arteries) and many layers of smooth muscle in large veins (not medium veins)

Question 5

5. What constitutes the epicardium?

Answer 5

The epicardium is the visceral layer of serous pericardium adhering to the outer surface of the heart.

It is of simple squamous epithelium (mesothelium), serosa (not adventitia), with underlying connective tissue and adipose.

It is continuous, reflecting back to form the parietal serous pericardium.

Question 6

6. What purpose does the adipose tissue surrounding the blood vessels in the coronary sulcus serve?

Answer 6

cushioning