Biology – Control and coordination in mammals | e-Consult
Control and coordination in mammals (1 questions)
Comparison and Contrast:
| Cell | |
| Sensory Neuron | Motor Neuron |
| Cell Body Location | Cell Body Location |
| Peripheral Nervous System | Central Nervous System |
| Axon Length | Axon Length |
| Generally long | Generally short |
| Myelination | Myelination |
| Often myelinated | May or may not be myelinated |
| Function | Function |
| Transmits sensory information to CNS | Transmits motor commands from CNS to effectors |
Myelin and Signal Transmission: Myelin is a fatty substance that insulates the axon. It is formed by glial cells (Schwann cells in the PNS and oligodendrocytes in the CNS). Myelin allows for saltatory conduction, where the action potential "jumps" from one Node of Ranvier (gaps in the myelin sheath) to the next. This significantly speeds up the transmission of nerve impulses compared to unmyelinated axons. Without myelin, signal transmission would be much slower and less efficient, limiting the speed and coordination of bodily responses. The speed of conduction is directly related to the diameter of the axon and the extent of myelination. Larger diameter axons and more extensive myelin sheaths result in faster conduction velocities.