Chapter 13 - The Central Nervous System Flashcards
What purpose does the spinal cord serve?
. Pathway for information to and from the brain
. Controls rapid reactions to specific stimuli
What does the brain control?
Thoughts, memories and behaviours
What are the major divisions of CNS in regards to the brains and spinal cord?
BRAIN
. Cerebrum: left and right hemispheres
. Diencephlon: includes thalamus and hypothalamus
. Brain stem: midbrain, pons, medulla oblongata
. cerebellum: posterior segment
SPINAL CORD
. extends inferiorly from brain stem to level of first or second lumbar vertebrae
What protects the CNS?
SKELETAL: Skull (brain), vertebrae (spinal cord)
MENINGES: 3 connective tissue layers, cranial and spinal meninges are continuous to each other.
CEREBROSPINAL FLUID: Fluid in a space between meninges and inside the brain cavity.
What makes up the meninges?
dura matter, arachnoid matter, pia mater
What makes up Dura Matter?
- Strongest, dense, irregular connective tissue
- Adheres to periosteum of cranial bones:
. 3 extensions to separate portions of the brains
.double layer forms dural sinuses - Separated from spinal cord by epidural space
What makes up Arachnoid Matter?
- Avascular web of delicate collagen and elastic fibres
- Separated from dura matter by subdural space
What makes up Pia Matter?
- Transparent and adheres to brain surface and spinal cord
- separated from arachnoid by subarachnoid space
What are the spaces associated with Meninges?
- Dural Sinuses: brain only (blood from brain to internal jugular veins)
- Subdural space: brain and spinal cord (interstitial fluid)
- Epidural space: spinal cord only (fat and connective tissue, interstitial fluid)
- Subarachnoid space: brain and spinal cord (cerebrospinal fluid, denticulate ligaments extend from pia matter to fuse with arachnoid mater to protect the spinal cord from sudden displacement)
