Brain Barriers

Question 1

What three components make up the Blood Brain Barrier?

Answer 1

1. Capillary endothelial tight junctions (primary)
2. Pinocytic Activity in endothelial cells
3. Astrocytic foot processes

Question 2

Which glucose configuration can travel across the BBB? Through what mechanism?

Answer 2

D-Glucose through Carrier Mediated Transport.

BBB is impermeable to L-Glucose.

Question 3

The Blood-CSF Barrier is formed by _______ .

Answer 3

tight junctions of choroid cuboidal epithelium

Question 4

What are circumventricular organs?

Answer 4

Midline ventricular structures of specialized tissues with absent BBB due to fenestrated capillaries

Question 5

How many circumventricular Organs are there? What are there names?

Answer 5

1. Organum vasculosum (lamina terminalis)
2. Neurohypophysis
3. Median eminence of the Hypothalamus
4. Subfornical Organ
5. Subcommissural Organ
6. Pineal Gland
7. Area Postrema

Question 6

Which is the only circumventricular organ with an intact BBB?

Answer 6

Subcommissural organ

Question 7

What is the only paired circumventricular organ? Where is it located?

Answer 7

Area Postrema on the floor of the 4th Ventricle

Question 8

What stimulates the area postrema to induce emesis?

Answer 8

Digitalis or apomorphine