Blood Brain Barrier and Blood Supply

Question 1

What substances can cross the BBB?

Answer 1

Oxygen, Carbon dioxide and lipid soluble molecules all cross by diffusion. Glucose crosses by carrier mediated transport

Question 2

Describe the circumventricular organs.

Answer 2

1. Areas without BBB
2. Primarily around 3rd and 4th ventricles
3. Lack tight junctions

Question 3

Describe the Blood-CSF barrier

Answer 3

1. Cuboidal epithelial cells and endothelial cells

Question 4

Describe the blood supply of the spinal cord

Answer 4

1. Anterior spinal artery
2. Posterior spinal artery
3. Artery of Adamkiewicz

Question 5

Discuss the Anterior spinal artery

Answer 5

Supplies anterior cord and lateral corticospinal tracts. Occlusion results in bilateral weakness

Question 6

Discuss the Posterior spinal artery

Answer 6

Paired; Supplies posterior columns and lateral corticospinal tracts. Occlusion results in sensory deficits

Question 7

Discuss the Artery of Adamkiewicz

Answer 7

Spinal cord watershed area in the lower thoracic and upper lumbar region. May be damaged in aortic surgeries.

Question 8

Describe the blood supply of the brain.

Answer 8

The parts:

1. Anterior circulation
2. Posterior circulation
3. Circle of Willis

Question 9

Explain the Anterior circulation of the brain.

Answer 9

Each internal carotid gives off ophthalmic, Posterior communicating and anterior choroidal arteries before dividing into the anterior and middle cerebral arteries.

Question 10

Explain the Posterior circulation of the brain.

Answer 10

The vertebral arteries arise from the subclavian artery

Question 11

Explain the Circle of Willis

Answer 11

Formed by anastomoses of branches of internal carotid arteries and terminal branches of the basilar artery; includes

1. Posterior/Anterior cerebral arteries
2. Posterior/Anterior communicating arteries

Question 12

What area does the Anterior Cerebral artery supply?

Answer 12

Medial surface of hemisphere; Leg/foot area of motor and sensory cortex.

Question 13

What area does the Middle Cerebral artery supply?

Answer 13

Lateral convexity of hemisphere, including language areas, motor and sensory cortex. Disruption causes contralateral hemiparesis, hemisensory loss, and Aphasia

Question 14

What area does the Posterior Cerebral artery supply?

Answer 14

Midbrain, thalamus, occipital lobe, and inferior surface of temporal lobe. Disruption causes homonymous hemianopia

Question 15

Discus the branches of the MCA and the consequences of occlusion

Answer 15

They supply the internal capsule, putamen, and globus pallidus. Disruption may cause hemiplegia