3. Arterial supply to the CNS

Question 1

The CNS accounts for 2% of BW, yet receives ___% of the total O2 consumption

Answer 1

20%

Question 2

The ___ matter is more vascularized thatn the ___ matter

Answer 2

grey, white

Question 3

What is the most vascularized structure of the brain?

Answer 3

hypothalamus

Question 4

Name the 5 pairs of arteries supplyng the brain.

Which ones arise from the cereberal arterial circle?

Answer 4

1. Rostral cerebral
2. Middle cerebral
3. Caudal cerebral
4. Rostral cerebellar
5. Caudal cerebellar

1-4 arise from the cerebral arterial circle

5. arises from the basilar artery

Question 5

Which is the largest artery supplying the brain?

Answer 5

Middle cerebral artery

Question 6

ROSTRAL cerebral artery (slides 6-7)
1. Origin
2. Supply

(know its trajectory)

Answer 6

1. Internal carotid artery (lateral to optic chiasm)
2. ROSTROMEDIAL surface of the cereberal cortex

Question 7

MIDDLE cerebral artery (slides 8-9)
1. Origin
2. Supply

(know its trajectory)

Answer 7

1. Internal carotid artery (rostral to pituitary gland)
2. LATERAL surface of the cerebral cortex

Question 8

CAUDAL cerebral artery (slides 10-11)
1. Origin
2. Supply

Answer 8

1. Caudal communicating artery (rostral to oculomotor nerve)
2. CAUDOMEDIAL aspect of the cerebral cortex,
   DIENCEPHALON and
   ROSTRAL midbrain

Question 9

ROSTRAL CEREBELLAR artery
1. Origin
2. Supply

Answer 9

1. Caudal communicating artery (caudal to oculomotor nerve)
   2) CAUDAL midbrain + ROSTRAL cerebellum

Question 10

CAUDAL CEREBELLAR artery
1. Origin
2. Supply

Answer 10

1. Basilar artery (near middle of medulla)
2. Caudoventral cerebellum + lateral medulla

Question 11

What is the cerebral arterial circle (circle of willis)?

Answer 11

Elongated arterial ring on the ventral surface of the brain, surrounding the pituitary gland and hypothalamus

Question 12

Name the four potential arterial channels to the circle of willis

Answer 12

1. Internal carotid artery
2. Basilar artery
3. Maxillary artery
4. Vertebral artery

Question 13

Which two arterial channels have an anastomosis ramus (and rete mirabile) to the internal carotid artery?

Answer 13

Maxillary & vertebral arteries

Question 14

The INTERNAL CAROTID artery gives rise to….

Answer 14

• Rostral cerebral artery
• Middle cerebral artery
• Caudal communicating artery

(Forms the ROSTRAL aspect of the circle)

Question 15

The BASILAR artery gives rise to….

Answer 15

• Caudal cerebellar artery
• Labyrinthine arteries
• Pontine branches

(rostral continuation of the ventral spinal artery; divises into 2 branches uniting with the caudal communicating artery, forming the CAUDAL aspect of the circle)

Question 16

The MAXILLARY artery connects with internal carotid via…

Answer 16

anastomosing ramus

Question 17

The VERTEBRAL artery supplies the circle either..

Answer 17

1) via anastomosing ramus to INTERNAL CAROTID
2) by connecting with the VENTRAL SPINAL artery (via segmental arteries), which becomes the BASILAR artery

Question 18

2 roles of the rete mirabile

Answer 18

• Cooling blood
• Attenuate arterial pulses before reaching the brain

Question 19

In which species are found…
1) Maxillary rete mirabile
2) Vertebral rete mirabile

Answer 19

1) cats, sheep, ox
2) ox

Question 20

Describe arterial supply to the brain in
DOGS

Answer 20

• INTERNAL CAROTID (rostral half)
• VERTEBRAL artery, via basilar artery (caudal half)

Question 21

Describe arterial supply to the brain in CATS & SHEEPS

Answer 21

• MAXILLARY, via anastomosing ramus and rete mirabile (whole brain except caudal medullar, supplied by vertebral artery)

Question 22

Describe arterial supply to the brain in OX

Answer 22

• MIXTURE of maxillary + vertebral blood, via their anastomosing ramus to the internal carotid

Question 23

3 longitudinal trunks along spinal cord

Answer 23

• 2 dorsolateral arteries
• 1 ventral spinal artery

Question 24

Anastomosing arteries

Answer 24

Arterial network on spinal cord surface connecting 3 longitudinal trunks. Alternate pathway in case of obstruction.

Question 25

3 segmental arteries

Answer 25

• SPINAL artery (R+L) - provides blood form aorta. Enters intervertebral foramen, gives rise to…
• ROOT arteries (dorsal + ventral)

Question 26

2 deep arteries

Answer 26

• VERTICAL arties (from ventral spinal artery)
• RADIAL arteries (from all other superficial arteries)

Question 27

Do deep arteries have anastomoses?

Answer 27

None. Obstruction cause neuron death in 8 minutes.

Question 28

Name the 3 spinal cord vascular zones and their arterial supply

Answer 28

3 vascular zones:
- INNER: vertical arteries
- MIDDLE: vertical + radial arteries
- OUTER: arteries