Unit 9 Flashcards
Blood Brain Barrier Function
It strictly regulates fluid and filters it. It helps prevent exposure to drugs, waste products in blood, and variations of substances. It serves as protection.
What is the BBB formed of
Cappilarirs surrounded by astrocytes
Negatives of BBB
If the Brain has an infection it cannot receive treatment
White Matter
The brain and spinal cord is from aggregation of myelinated axons from many neurons
Gray matter
The brain and spinal cored formed from neuronal cell bodies and dendrites (no myelin) (appears light)
Dura Mater
is a thick outermost layer that is strong and protects the brain and the spinal cord.
2 layers in Dura Mater
Meningefal (external) and periostea (internal)
Arachoid mater
A cobwebby layer (middle) is external to collagen and elastic fibres
Pia Mater
thin layers that is directly covering brain surface. The inner most layer areolar tissue
Epidural space
Runs outside the dura mater
Subora
Between dura and arachnoid layer
Subarachnoid space
between the arachnoid mater externally and pia mater internally
Cerebral Spinal Fluid
A clear fluid that circulates through the internal cavities in the brain and spinal cord.
Cerebral fluid Purpose
it is buoyant, floats around and reduces 95% if the weight without it the brain would sink. It stabilizes, transports nutrients to brain, removes waste, protects nervous tissue .
1) Shock absorber
2) Maintains pH
3) circulates
CFS production
- Produced by chore plexus in the ventricles
- CSF flows from the lateral ventricles through into the ventricles foremen into third ventricle and then through the cerebral aqueducts into the fourth ventricles
- As the CSF flows through the subarachnoid space it provides buoyancy to support the brain
- Excess CFS flows into the arachnoid cilli the drains into the Dural venous sinuses. The greater pressure on the CSF in the subarachnoid space ensures that CSF moves into the venous sinuses without permitting venous blood to enter the subarachnoid