Biopsychology: physiological psychology

Structure and function of neurons

Neurons are nerve cells. The human nervous system has around 100 billion neurons. Neurons send and receive electrical information.

· Sensory neurons carry information from the sense organs, muscles, skin and joints, which is known as the peripheral nervous system and carries it to the spinal cord and brain which is known as the central nervous system.

· Motor neurons transmit messages away from the CNS to the muscles and organs in the body

· Interconnecting neurons are found only in the brain, spinal cord and visual system. They receive messages from the sensory neurons and pass them to either interconnecting neurons or to motor neurons.

The interaction of these three types of neuron can be seen in the knee jerk reflex. When something hits the knee it is detected by receptor cells in the PNS which then sends a message to a sensory neuron. The message reaches the CNS where it connects an interconnecting neuron. This then transfers the message to a motor neuron, which carries to the muscle in the knee which makes it move or jerk.

· Motor, they carry messages from the CNS to muscles and organs. It has short dendrites and long axons.

· Interconnecting, transfer messages from the sensory neurons to either other interconnecting neurons or to motor neurons. It has short dendrites and short or long axons.

· Sensory, they carry messages from the PNS to the CNS. It has long dendrites and short axons.

Synaptic transmission

A synapse is a specialised gap that allows electrical messages to…