3. Arterial supply to the CNS Flashcards
The CNS accounts for 2% of BW, yet receives ___% of the total O2 consumption
20%
The ___ matter is more vascularized thatn the ___ matter
grey, white
What is the most vascularized structure of the brain?
hypothalamus
Name the 5 pairs of arteries supplyng the brain.
Which ones arise from the cereberal arterial circle?
- Rostral cerebral
- Middle cerebral
- Caudal cerebral
- Rostral cerebellar
- Caudal cerebellar
1-4 arise from the cerebral arterial circle
- arises from the basilar artery
Which is the largest artery supplying the brain?
Middle cerebral artery
ROSTRAL cerebral artery (slides 6-7)
1. Origin
2. Supply
(know its trajectory)
- Internal carotid artery (lateral to optic chiasm)
- ROSTROMEDIAL surface of the cereberal cortex
MIDDLE cerebral artery (slides 8-9)
1. Origin
2. Supply
(know its trajectory)
- Internal carotid artery (rostral to pituitary gland)
- LATERAL surface of the cerebral cortex
CAUDAL cerebral artery (slides 10-11)
1. Origin
2. Supply
- Caudal communicating artery (rostral to oculomotor nerve)
- CAUDOMEDIAL aspect of the cerebral cortex,
DIENCEPHALON and
ROSTRAL midbrain
ROSTRAL CEREBELLAR artery
1. Origin
2. Supply
- Caudal communicating artery (caudal to oculomotor nerve)
2) CAUDAL midbrain + ROSTRAL cerebellum
CAUDAL CEREBELLAR artery
1. Origin
2. Supply
- Basilar artery (near middle of medulla)
- Caudoventral cerebellum + lateral medulla
What is the cerebral arterial circle (circle of willis)?
Elongated arterial ring on the ventral surface of the brain, surrounding the pituitary gland and hypothalamus
Name the four potential arterial channels to the circle of willis
- Internal carotid artery
- Basilar artery
- Maxillary artery
- Vertebral artery
Which two arterial channels have an anastomosis ramus (and rete mirabile) to the internal carotid artery?
Maxillary & vertebral arteries
The INTERNAL CAROTID artery gives rise to….
- Rostral cerebral artery
- Middle cerebral artery
- Caudal communicating artery
(Forms the ROSTRAL aspect of the circle)
The BASILAR artery gives rise to….
- 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)
The MAXILLARY artery connects with internal carotid via…
anastomosing ramus
The VERTEBRAL artery supplies the circle either..
1) via anastomosing ramus to INTERNAL CAROTID
2) by connecting with the VENTRAL SPINAL artery (via segmental arteries), which becomes the BASILAR artery
2 roles of the rete mirabile
- Cooling blood
- Attenuate arterial pulses before reaching the brain
In which species are found…
1) Maxillary rete mirabile
2) Vertebral rete mirabile
1) cats, sheep, ox
2) ox
Describe arterial supply to the brain in
DOGS
- INTERNAL CAROTID (rostral half)
- VERTEBRAL artery, via basilar artery (caudal half)
Describe arterial supply to the brain in CATS & SHEEPS
- MAXILLARY, via anastomosing ramus and rete mirabile (whole brain except caudal medullar, supplied by vertebral artery)
Describe arterial supply to the brain in OX
- MIXTURE of maxillary + vertebral blood, via their anastomosing ramus to the internal carotid
3 longitudinal trunks along spinal cord
- 2 dorsolateral arteries
- 1 ventral spinal artery
Anastomosing arteries
Arterial network on spinal cord surface connecting 3 longitudinal trunks. Alternate pathway in case of obstruction.
3 segmental arteries
- SPINAL artery (R+L) - provides blood form aorta. Enters intervertebral foramen, gives rise to…
- ROOT arteries (dorsal + ventral)
2 deep arteries
- VERTICAL arties (from ventral spinal artery)
- RADIAL arteries (from all other superficial arteries)
Do deep arteries have anastomoses?
None. Obstruction cause neuron death in 8 minutes.
Name the 3 spinal cord vascular zones and their arterial supply
3 vascular zones:
- INNER: vertical arteries
- MIDDLE: vertical + radial arteries
- OUTER: arteries
