Neurons Flashcards
What is a neuron?
An electrically excitable cell that transmits nerve impulses.
A nerve cell!
What is the structure of a neuron?
Thin and long
There is a lot of variation
All neurons consist of:
- cell body (soma)
- dendrites
- axon
- axon hillock
- axon terminal
What is an axon?
The long slender projection of the neuron
Typically conducts electrical impulses away from neuron’s cell body.
What is the function of an axon?
Transmit information to different neurons, muscles and glands
What are dendrites?
Branched projections of a neuron that act to transmit the electrochemical stimulation received from other neural cells to the cell body of the neuron.
What surrounds the main body of the axon?
Myelin sheath
What is an axon hillock?
Where axon left the cell body
What cells myelinate axons in the CNS?
Oligodendrocytes
One cell can myelinate many neurons - I think?
What cells myelinate axons in the PNS?
Schwann cells
What are nodes of Ranvier and what is salutatory conduction?
Nodes of Ranvier - gaps between each Schwann/oligodendrocyte cell.
The nodes mean that depolarisation can jump from node to node - making it quicker, this is called salutatory conduction.
Name some neurons that are different in structure.
Unipolar
Multipolar
Bipolar
Pseudounipolar
Name some neurons that are different in function.
Afferent (PNS-CNS)
Efferent (CNS-PNS)
Interneurons (between aff and eff in CNS)
What is myelin?
A phospholipid bilayer
What is the difference between myelinated and unmyelinated neurons?
Myelinated neurons are:
Generally larger in diameter
Have a faster conductivity speed
What is a synapse?
Structure that permits a neuron (or nerve cell) to pass an electrical or chemical signal to another cell (neural or otherwise)
