Neuron Structure and Function

• Neurons are information messengers that use electrical impulses and chemical signals to transmit information between different areas of the brain and between the brain and the rest of the nervous system
• Sensory neurons carry information from the PNS to the spinal cord and brain; they are unipolar and have receptor cells and axons
• Motor neurons, located in the CNS, connect effectors such as muscles and glands; short dendrites and long axons
• Relay neurons make up the majority of the cells in the CNS, they connect sensory, motor and other relay neurons; short dendrites and long axons
• Dendrites receive the nerve impulse or signal from adjacent neurons
• Cell body (soma) determines the strength of the message it receives from dendrites; if strong enough, it will send messages down the axon
• Axons are where the electrical signals pass along
• Myeline sheath insulate/ protect the axon from external influences that might affect the transmission of the nerve impulse down the axon
• Synaptic terminals are terminal buttons that send signals to an adjacent cell
• Synaptic transmission is the chemical and electrical communications between cells to respond to the stimulus that comes from the environment and inside our body
• The synaptic gap is an unidirectional switch between neurons
• Action potential is an electrical impulse that travels along the axon and allows neurotransmitters to be released to the synaptic gap
• A cell in resting state is polarised- the inside of the membrane is negatively charged and the outside is positively charged
• A stimulate cell is a depolarised neuron- the inside of the membrane will be charge positively and the outside of the membrane will be charged negatively; depolarised when action potential is happening