Archive of ‘Grade 12’ category

Nerve Cells- Edublog Post

 

The nerve cells in our body take on 3 different forms: sensory, motor and inter-neurons

The function of a neuron is to carry electrical messages around your body. They are composed of  the cell body, the dendrites, and the axon. The dendrites are what conduct messages towards the cell body, the axon does the opposite, and conducts messages away from the cell towards the next cell. Motor neurons have short dendrites and long axons, where as sensory neurons and inter-neurons have longer dendrites and shorter axons.

Action potential is a process that occurs in the neuron. A neuron has negative potassium ions outside the membrane and positive sodium ions inside. The action potential travels down the axon and while this is happening, there is a change in the membrane in polarity. This happens by the axon moving the sodium ions outside the cell and the potassium ions inside the cell.

The action potential reaches the axon terminal (the synapse) and causes the release of neurotransmitters into the synaptic gap. There are two membranes in the synapse, the pre-synaptic membrane of the axon and the post synaptic membrane of the dendrite. The space between these two membranes causes the synaptic gap. When the receptor receives the neurotransmitter, the neurotransmitter can either be received as excitatory or inhibitory. When receiving a neuron, Excitatory stimulates Action potential, whereas as inhibitory represses the action potential. If the excitatory charge is greater than the inhibitory charge, action potential is produced.