Note the variety both of neuronal shapes and of the branching patterns of their processes.Ĭan you find bipolar, pseudopolar or multipolar neurons?Īs most of the nerve cell bodies are either in the brain or spinal cord, or in ganglia, just outside the spinal cord, and the synapsesĪt the end of the axon can be long distances away (i.e innervating muscles at the end of your foot or arm) the axons can be around 1 meter long! This section shows a thick section from the cerebral cortex, stained using Golgi-Cox method, which stains neurons black. (Fast anterograde flow involves microtubules, and the microtubule motor protein called kinesin.) There is also retrograde flow, in which unused or recycled constituents are returned to the cell body. There is a slow transport system of a few millimetres a day, and a fast system, which is about 100 times faster. The red arrows show the direction of nerve impulse transmission.Īs well as conducting electrical impulses, the cell has to transport proteins, lipids, and other macromolecules,įrom the cell body to the synapses ( anterograde direction), because all of the protein making machinery (ribosomes, endoplasmic reticulum) is in the cell body. Long - around 1 metre, and vary in diameter from 0.2 to 20 µm The axon: a single nerve 'fibre' which transmits impulses to the distal end.(brain and spinal cord), or in the ganglia (which lie just outside the spinal cord) of the peripheral nervous system. Most of the cell bodies of neurons are in the central nervous system These are fairly short, with lots of branches,Īnd they are the points at which nerve impulses are received by the cell. Dendrites extend from the cell body ( dendron - greek for tree).Neurons (Nerve cells) are specialised cells that conduct electrical impulses.Īll neurons have the same basic structure:

Dendrite vs axon