Nervous system Flashcards
(23 cards)
How many types of glia cells are there and what are their names?
- Astrocytes
- Microglia
- Ependymal
- Oligodendrocytes
- Schwann
Where are astrocytes located?
Around the brain capillaries in the CNS
What is the Blood Brain Barrier
The tight junction of epithelial and astrocytes formed around the brains capillaries. Extra precaution against pathogens, viruses, bacteria, etc from entering the brain through the blood
What are the most common types of glia and what do they look like?
Astrocytes and they are star shaped
What do astrocytes connect to?
Brain capillaries and other neurons. Used to transfer nutrients from blood to neurons
What are microglia?
Small, stationary cells that move when brain tissue is inflamed. CNS
Are microglia phagocytes?
Yes.
Are Ependymal cells found in the PNS?
No. They are located only in the CNS
What do Ependymal cells do?
Line the fluid filled cavities of the CNS. Some produce the CSF while others function is to circulate it.
What is the role of oligodendrocytes?
To hold nerve divers together and produce myelin sheaths in the CNS
What are neurons?
Excitable cells that initiate and conduct impulses.
What do impulses do?
Make every nervous system possible.
What are tracts?
Bundle of nerve fibres in the CNS
Do tracts have connective tissue coverings?
No.
Where are Schwann cells located?
In peripheral neurons
What is the function of a schwann cell?
To support nerve fibres and form myelin sheaths
What are gaps in myelin sheaths called?
Node of ranvier
What is neurilemma?
The layer between the myelin sheath and the Schwann cells. It is essential for nerve regrow this
What is a neurolemmacyte?
Any cell that covers the axons of a peripheral nerve.
What makes up the neural sheath?
The myelin sheath plus the neurilemma. The whole Schwann wrapping around the axon.
What are satellite cells?
Schwann cels that cover and support cell bodies in the PNS
What is a perikaryon?
The cell body of a neuron
What is the function of a ribosomes in neuron?
Provide protein molecules (neurotransmitters) needed for transmission of nerve signals from one neuron to another
