Neural Protection and Nourishment In The CNS

Question 1

Components of nourishment and protection

Answer 1

Meninges and ventricular system protect

CNS and blood flow nourish

Question 2

Meninges

Answer 2

3 layers of non neural tissue

Dura Mater (outer)
Follows shape of the skull, thickest and most protective

Arachnoid Mater (middle)
Subarachnoid space is below

Pima Mater (inner)
Follows crevices of the brain

Brain case = calvaria

Question 3

Coatings that separate hemispheres

Answer 3

Falx Cerebri
Tentorium Cerebelli (separates cerebrum and cerebellum)
Falx Cerebelli (divides Cerebelli)

Brain bleeds and toxins do not as easily affect other lobes

Question 4

Ventricular System

Answer 4

Lateral x2 - see at coronal view
To interventricle foramen
3rd ventricle - horse’s head
To cerebral aqueduct
4th Ventricle - inferior

Spaces not structures
Cushions brain
Circulates CSF

Question 5

CSF

Answer 5

Cerebrospinal Fluid
Created in choroid plexus (walls of ventricles)
Moves from high to low pressure
Goes through fourth ventricles and can either follow down in the apertures (channels) to the subarachnoid space or spinal cord. Exits at sagittal sinus!

Question 6

Oxygen

Answer 6

Brain is 2% of body weight

20% of oxygen consumption

Question 7

Blood Flow

Answer 7

Carotid Adteries
External to face
Internal to brain

Vertebral Arteries

Question 8

Cerebral Arteries & Circle of Willis

Answer 8

Carotid (internal/external)
Vertebral (merge @ brainstem to form basilar artery)
Circle of Willis (sends to anterior, middle, and posterior)
Redundant blood supply
Middle is watershed area
If below circle, it’s okay!
If above, in trouble.