- The structure and function of neurons:
- Types and functions of neurons:
- There are 100 billion nerve cells (neurons) in the human nervous system, 80% of which are located in the brain. By transmitting signals electirically and chemically, these provide the nervous ssytem with its primary means of communication. There are 3 types of neuron:
- Motor neurons - connect the CNS to effectors such as muscles and glands. They have short dendrites and long axons.
- Sensory neurons - carry messages from the PNS to the CNS. They have long dentries and short axons.
- Relay neurons - connect sensory neurons to motor or other relay neurons. They have short dentries and short axons.
- The structure of a neuron: