Histology

Question 1

List blood-brain barrier components (4).

Answer 1

Capillary endothelial cells → have tight junctions
The basal lamina
Astrocytes
Pericytes

Question 2

Brain vs. Peripheral Capillaries in terms of structural differences:

Answer 2

– Absence of fenestrations
– More extensive tight junctions
– Numerous mitochondria
– Prominent basal lamina and astrocyte foot processes

Question 3

Brain vs. Peripheral Capillaries in terms of functional differences.

Answer 3

– Impermeable to most substances
– Sparse pinocytotic vesicular transport
– Increased expression of transport and carrier proteins:
receptor mediated endocytosis
– No gap junctions, only tight junctions
– Limited paracellular and transcellular transport

Question 4

what is the role of pericytes:

Answer 4

Role in structural stability of vessel wall

Phagocytic activity

Question 5

why circumventricular organs are not enclosed by BBB.

Answer 5

need to respond to factors
present in systemic circulation;
neuroendocrine function

Question 6

The blood brain barriers prevent passage of some materials
(such as antimicrobial drugs) into the CNS

Answer 6

yohh