Histology - Circulatory System

Question 0

Angiotensin-converting enzyme (ACE)

Answer 0

Cleaves angiotensin I to generate angiotensin II

Question 1

Tunica intima

Answer 1

Is composed of a simple squamous epithelium and the subendothelial connective tissue.

The endothelial cells provide in a smooth surface and in secreting:

• Collagen type II
• Collagen type IV
• Collagen type V
• Lamin
• Endothelin
• Nitric oxide
• von Willebrand factor

The endothelial cells also posses membrane bound enzymes, such as:

• Angiotensin-converting enzyme (ACE)
• enzymes that inactivate: bradykinin, serotonin, prostglandins, thrombin, and norepinephrine.

The endothelial cells bind lipoprotein lipase

Question 2

Lipoprotein lipase

Answer 2

The enzyme that degrades lipoproteins

Question 3

The subendothelial layer of the tunica intima

Answer 3

Is composed of loose connective tissue and a few smooth muscle cells, both arranged longitudinally.

Question 4

The internal elastic lamina

Answer 4

Beneath the subendothelial layer.

Well developed in muscular arteries.

Separates the tunica intima from the tunica media.

Composed of elastin, which permits diffusion of substances into the deeper regionsof te arterial wall to nourish the cells there.