BLOOD SUPPLY OF CNS/ MENINGES/ VENTRICULAR SYSTEM/ CSF PRODUCTION

Question 1

How is CSF produced

Answer 1

• is produced by the choroid plexus- a vascular proliferation of the ependymal layer- in lateral and 3rd and 4th ventricles
• is produced by ultrafiltration of plasma and active transport

Question 2

What is CSF

Answer 2

Cerebrospinal fluid

Has low protein and glucose levels due to ten needing t be actively transported

Question 3

What is the function of CSF

Answer 3

• protection - separates the brain from blood
• Support- buoyancy
• Nutrition

Question 4

How is CSF production regulated

Answer 4

• rate of CSF production depends on blood pressure

- Arachnoid villi act as one way valves to regulate pressure within the CSF

Question 5

Where is CSF outside the brain

Answer 5

The meninges

Question 6

What are the 3 layers of the meninges

Answer 6

• Dura mater
• Arachnoid mater
• Pia mater

Question 7

Where is th dura mater found

Answer 7

Outer layer of the meninges
In skull= attaches to periosteum
In spinal cord= separates from periosteum by the epidural space filled with fat

Question 8

Decribe the arachnoid mater

Answer 8

-fine layer found intbetween the dura and pina mater

Question 9

Describe the pina mater

Answer 9

Thin layer which is adherent to undying brain and spinal cord

Question 10

Describe the lateral ventricles

Answer 10

Found in the telencephalon

• there is variation in size between individuals and breeds
• often difference in size between the 2 sides of the brain

Question 11

What is the functions of the meninges

Answer 11

• protection
• containment of CSF
• maintenance of blood brain barrier
• support

Question 12

What is the blood brain barrier

Answer 12

Is the selective barrier between the circulating blood and the functional tissue of the nervous system

Question 13

What are the capillaries of the brain surrounded by

Answer 13

• closed overlapping epithelium
• dense basement membrane
• processes of astrocytes

Question 14

Which pairs of vessels supply the brain

Answer 14

• Rostral cerebral arteries
• Middle cerebral arteries
• Caudal cerebral arteries
• Rostral cerebellar arteries
• Caudal cerebellar arteries

Question 15

What does the rostral cerebral arteries supply

Answer 15

Medial aspect of the cerebral hemispheres

Question 16

What does the middle cerebral arteries supply

Answer 16

Lateral and ventrolateral aspects of the cerebral hemispheres

Question 17

What does the caudal cerebral arteries supply

Answer 17

Occipital lobes

Question 18

Why does the rostral cerebellar arteries supply

Answer 18

The rostral aspects of the cerebellum

Question 19

What does the caudal cerebellar arteries supply

Answer 19

Caudal and lateral aspects of the cerebellum

Question 20

Describe the structure and location of the arterial circle (circle of Willis)

Answer 20

Sits on base of brain around the pituitary gland with blood vessels radiating off
It is supplied by the basilar artery underneath and internal carotid artery at the top

Question 21

What artery up plies the internal carotid artery

Answer 21

Can either be supplied by the:
-common carotid artery 
-external carotid artery 
- vertebral artery 
Varies between species

Question 22

What is the maxillary rete mirabile and what does it do

Answer 22

Is a network of vessels located within the cavernous sinus, it is postulated to cool the blood or reduces fluctuations from pulsatile flow

Question 23

Describe the blood supply to the spinal cord

Answer 23

Supplied through the segmental arteries:
-cervical -vertebral artery
-thoracic- intercostal artery
-lumbar- aorta 
Which then separate t supply blood to the whole spinal cord