Brain & Nervous System 2 Flashcards
1
Q
Describe astrocytes.
A
- Star-shaped glial cells
- Support and protect neurons
- Contribute to blood brain barrier
- Protects brain from toxins/drugs in blood
- Projections contact capillaries and neurons
- Role in inflammatory response in brain
- Control and coordinate other glial cell types.
2
Q
Define the blood brain barrier.
A
Continuous capillaries which are less permeable and leaky than other capillaries which fit together like jigsaw pieces. It is permeable to fat-soluble substances e.g. Anaesthetics, alcohol easily cross BBB.
3
Q
Define Schwann Cells.
A
- PNS only
- Rich in lipid and produce myelin
- Wrap around axons
- Enhances speed of electrical conductance
- Gives characteristic white appearance.
4
Q
Define saltation conductance.
A
When impulses jump between Nodes of Ranvier.
5
Q
Define Oligodendrocytes.
A
- CNS only
- myelin producing cells
- highly branched cells
- Single ODC produces myelin for several neurons.
6
Q
Describe Multiple Sclerosis.
A
- Disease of myelin - immune system destroys sheath
- Reduces speed and success of nerve conduction (loss of saltatory conduction)
- Symptoms include pins and needles, loss of motor function and visual disturbance.
7
Q
Describe microglia.
A
- Type of glial cell
- Scavenge CNS looking for debris to ingest
- act as phagocytes
- Primary immune defence within the CNS
8
Q
What are the functions of glial cells?
A
- Support and hold neurons in place
- Nourish and supply nutrients and oxygen
- Insulate neurons electrically
- Protect from pathogens.
