U3 Nervous system: Protection of the central nervous system

Question 1

What are the bones that protect the central nervous system?

Answer 1

Cranium
- Part of the skull that encloses and protects he brain

Vertebra
- Stacked bones that form the vertebral canal and protect the spinal cord

Question 2

What are the meninges that protect the central nervous system?

Answer 2

Dura mater
- Tough outer layer that provides protection for the brain
- Sticks closely to the bones of the skull

Arachnoid mater
- Middle meningeal layer
- Loose mesh of fibres filled with fluid to cushion the brain

Pia mater
- Delicate inner meningeal layer
- Contains many blood vessels
- Sticks closely to the surface of the brain and spinal cord

Question 3

What is cerebrospinal fluid and its functions?

Answer 3

• Fluid that occupies the space between the middle and inner layers of meninges and circulates through the cavities in the brain and a canal in the centre of the spinal cord

Functions

Protection
- Shock absorber: cushions any blows or shocks the central nervous system may endure

Support
- Suspends the brain inside the cranium, allowing it to float

Transport
- CSF is formed in the blood and circulates through the CNS, taking nutrients to cells of the brain and spinal cord and carrying away their wastes into the blood