Arteries of the Brain

Question 1

importance of blood to the brain

Answer 1

The adult brain requires 750 mL (1 quart) of oxygenated every minute to maintain normal activity
20% of arterial oxygen is consumed by the brain
Cessation of blood flow for 5-10 sec temporarily changes neural activity
As little as 5 minutes without blood flow to the brain can cause irreversible neuronal damage

Question 2

Anterior circulation

Answer 2

Internal Carotid
“Anterior Circulation”
75% of CVAs occur here

Carotid foramen
Also, ophthalamic comes from the internal carotid

Question 3

Posterior circulation

Answer 3

vertebral artery

Question 4

Internal Carotid

Answer 4

One of the two terminal branches of the common carotid
It has cervical, petrous, cavernous, and cerebral parts
The cerebral part gives off the ophthalmic artery
Terminates by dividing into ACA and MCA

Question 5

Internal carotid branches

Answer 5

Anterior Cerebral
Recurrent artery of Heubner (MSA) -- Perforating
Middle Cerebral
Ophthalmic
Hypophyseal
Anterior Choroidal-- Perforating
Posterior Communicating

Question 6

which artery gives off a bunch of branches in the Isle of Reil?

Answer 6

the MCA

Question 7

arteries of sudden death

Answer 7

Lenticulostriate arteries, come off the MCA. They are without anastamoses, much smaller than MCA and have thin walls.

Question 8

perforating arteries (off the MCA) oclusion or malformation can cause…

Answer 8

lacunar strokes

(less than 20 mm)
In the deep cerebral white matter, basal ganglia, or pons
Caused by single perforating artery occlusion

Question 9

A CVA in the internal capsule can…

Answer 9

mimic the effects of a MCA-ACA stroke

Because the internal capsule contains both ascending and descending fibers, CVA’s can be both sensory and motor. A small area damaged in the internal capsule carries diffuse fibers across the cortex

Question 10

Vertebral arteries

Answer 10

Vertebral arteries enter the foramen magnum and unite at the caudal end of the pons to form the basilar artery
Basilar artery - ends by dividing into the posterior cerebral arteries (PCA) at the superior end of the pons. The basilar artery also gives
superior cerebellar artery
pontine arteries
labyrinthine artery
anterior inferior cerebellar artery (AICA)

Question 11

Circle of Willis

Answer 11

Connects the Anterior and Posterior Circulations

Also, helps prevent complete blockage if one area is blocked
Internal carotid artery circulation can use contralateral circulation

Question 12

what’s a big hint that there is occlusion of the PCA?

Answer 12

visual deficits.

Question 13

Basilar Artery Branches:

Answer 13

Posterior cerebral
SCA
Pontine
AICA

Question 14

supply to the thalamus

Answer 14

thalamoperforating arteries from the PCA

thalamic lesion tends to affect pain and temperature– hyperalgesia

Question 15

Pons, Medulla, and cerebellum are supplied by

Answer 15

basilar, pontine, cerebellar and basilar arteries

Question 16

Venous drainage of the brain

Answer 16

Thin-walled vessels in the subarachnoid space with no valves or muscle layer.

Pierce the arachnoid mater and meningeal layer of the dura mater to drain into the dural venous sinuses.

Uses the meninges layer to get out.

Question 17

Superficial cerebral veins drain into

Answer 17

the superior sagittal sinus

Question 18

Deep cerebral veins drain into

Answer 18

the straight sinus

Question 19

Basal vein is

Answer 19

ACTUALLY a superficial vein. HUGE variations in venous anatomy (hypoplasias)…most consistent in the deep cerebral veins

Question 20

cerbrovascular accidents are concentrated where?

Answer 20

at branchpoints in the anterior circulation

Question 21

Infarct

Answer 21

Infarct (Umbra)
Necrosis of tissue due to lack of blood supply
Uncontrolled cell death

Question 22

Prenumbra

Answer 22

Peri-infarct zone
Apoptosis
Controlled cell death
Possible recovery