... rapidly, generally speaking.
Many neurons have insulating sheaths of myelin
around their axons, which enable their action potentials to travel ... nervous system and Schwann cells in the peripheral nervous system. The myelin
sheath in peripheral nerves normally runs along the axon in sections about ...
... each foot. These single-cell fibers may extend a metre or even longer.
In vertebrates generally, the axons of many neurons are sheathed in myelin
, which is formed by either of two types of glial cells : Schwann cells ensheathing peripheral neurons and oligodendrocytes insulating those ...
... on the surface of cerebral cortex, as well as in clusters called nuclei deep within the brain. White matter refers to axons and their surrounding myelin
insulation, which gives this tissue its white color. White matter is found in bundles of fibers known as tracts which connect the different parts of ...
... rapid action potential propagation. Mammals also use this trick for increasing the speed of signals in the nervous system, but they can also use myelin
to accomplish this, so most human neurons are releatively small.
Other experimental systems for the study of cell size regulation
Magnetic resonance imaging
... tissues however the diffusion is very often anisotropic . For example a molecule inside the axon of a neuron has a low probability to cross a myelin
membrane. Therefore the molecule will move principally along the axis of the neural fiber. Conversely if we know that molecules locally diffuse ...