AQA 7181/7182 Psychology - Biopsychology - Neurons and Synaptic Transmission

The structure and function of neurons

In the human body, there is 100 billion neruons (80% of which are in the brain). Neurons provide the nervous system with its primary form of communication. They communicate eletrically and chemically.

Types of neuron

The are three types of neurons: motor neurons, sensory and relay neurons. Each neuron contains a similar structure, but there location, structure and function differ from each other.

Sensory neurons

Sensory neurons are found in the eyes, ears, tongue, and skin. They carry nerve impulses to the spinal cord and brain. Once these impulses reach the brain they are translated into 'sensations' such as vision, hearing, taste and touch. Not all sensory neurons reach the brain and some stop at the spinal cord to allow for swift reflex actions.

Relay neurons

These neurons are found between sensory input and motor output. Relay neurons can also be found in the brain and spinal cord and allow sensory/motor neurons to communicate. 

Motor neurons

Motor neurons are found in the CNS and it is there function to control muscle movements. When motor neurons are stimulated they release neurotransmitters which bond to the receptor sites on muscles to trigger a response, which leads to motion.

The structure of a neuron

All neurons share the same basic structure.

• Cell body: includes nucleus, the genetic…