Builiding Blocks Of The Nervous System Flashcards
1
Q
What is the function of the nervous system?
A
- Generate and transmit electrical signals
- Communicate with other cells
- Form complex circuits with one another - Form complex circuits within the CNS grey matter, and these regions of grey matter communicate with one another via axons running through the white matter
2
Q
Describe the key characteristics of nerve cells
A
- Cell body - Contains all normal machinery
- Dendrites - Provides large SA for receiving information from other cells
- Axon (nerve fibre) - Transmits information to other nerve cells
- Synaptic boutons (synaptic terminal) - Location where nerve cell releases neurotransmitter and passes info to other
3
Q
What is the function of the microglia?
A
Defence - They’re immune cells
4
Q
What is the function of astrocytes (astroglia)?
A
- Nutrition and biochemical support
- Control the environment of nerve cells
- They transport substances to and from nerve cells, assisting them in building and breaking down molecules and process them and they are a key component of the system that draws CSF through the brain to wash out toxins and debris
- They instruct the capillaries to form the BBB (blood-brain barrier)
- They swaddle nerve cell bodies and dendrites, adjusting the concentration of substances in the fluid layer between them - Pump fluid in or out
5
Q
What is the function of the myelin sheath (myelin glial cells)?
A
- Ogliodendrocytes are the cells of the CNS that produce myelin
- They increase the speed of neural signals
6
Q
What is grey matter composed of?
A
- Astrocytes - provide biochemical support for the nerve cells
- Nerve cells and their dendrites
- Astrocytes associated with a dense capillary network
- In grey matter, ogliodendrocytes myelin some axons, but most axons in grey matter are unmyelinated
- Nerve cell bodies and their dendrites
- Local axons forming complex electric circuits
7
Q
What is white matter composed of?
A
- Bundles of axons linking different regions of grey matter
- Astrocytes associated with capillaries
- Myelinating ogliodendrocytes - This myelination is what gives white matter its white colour
8
Q
What is the function of the blood brain barrier and meninges and CSF?
A
- Physical support and protection
- Brain tissue has very high metabolic activity
- In body - Capillary wall made of endothelial cells, has gaps so blood and interstitial fluid can mix, but this isn’t possible in the brain so:
- Endothelial cells in capillary walls of brain make tight junctions, so form an unbroken barrier between plasma and brain barrier
9
Q
What is the blood-brain barrier?
A
Protective layer that lines the inner surfaces of the blood vessels inside your brain
