neurons

Question 1

what are neurons?

Answer 1

specialised cells that conduct and process information. the basic unit of the nervous system

Question 2

what are dendrites?

Answer 2

they branch off from the cell body - specialise in receiving information from both the environment and other cells.

Question 3

what is the axon?

Answer 3

it leads away from the cell body and carries action potentials to other neurons.

Question 4

what is the synapse?

Answer 4

the gap between the axon terminal and the dendrites of another neuron. this is how cells communicate and carry information.

Question 5

what is the axon terminal?

Answer 5

the end of an axon which forms a synapse on a neuron or another target cell.

Question 6

what are the 3 principle components of a synapse?

Answer 6

1. pre-synaptic membrane - the axon terminal of the pre-synaptic neuron
2. the synaptic cleft - a gap of about 20-40 nanometres that separates the neurons
3. post-synaptic membrane - is on the surface of the dendrites/cell body of the post-synaptic neuron

Question 7

what are synaptic vesicles?

Answer 7

small, spherical structures found in pre-synaptic axon terminals, which contain neurotransmitter molecules.

Question 8

what is a neurotransmitter?

Answer 8

a chemical released from the pre-synaptic axon terminal that serves as the basis of communication between the neurons.

Question 9

what is a receptor and what do they cause?

Answer 9

a molecule that binds and reacts with neurotransmitters.

this causes electrical changes in the post-synaptic cell.

Question 10

what is the axon hillock?

Answer 10

a cone shaped area from which the axon originates out of the cell body.

Question 11

what function does the axon hillock provide?

Answer 11

it is the integration zone - it gathers and integrates information from all of the synapses on the neurons dendrites.

Question 12

what are glial cells?

Answer 12

non-neural brain cells that provide structural, nutritional and other types of support to the brain

Question 13

what are the 3 basic forms of glial cells and their functions?

Answer 13

1. astrocyte - provides nutrients and regulates blood flow
2. microglial - removes cellular debris from injured or dead cells.
3. oligodendrocyte - forms myelin by wrapping myelin around the axons of cells.

Question 14

what is myelin?

Answer 14

a fatty insulation around an axon that improves the speed and conduction of action potentials.