- Plexus
A plexus is a network. It has more specific meanings in multiple fields.
Biology
In
biology it has multiple meanings.Nervous system
In many animals the processes of
neuron s join together to form a plexus or nerve net.In vertebrates
In vertebrates, a plexus is an area where
nerve s branch and rejoin, for example thebrachial plexus made up of the spinal nerves which enter the arm and the solar plexus above thestomach .Almost a hundred such plexuses have been named in the human body, but the four primary
nerve plexus es are thecervical plexus ,brachial plexus ,lumbar plexus , and thesacral plexus .In invertebrates
Plexuses is the characteristic form of
nervous system in thecoelenterate s and persists with modifications in theflatworm s. The nerves of the radially symmetricechinoderm s also take this form, where a plexus underlies the ectoderm of these animals and deeper in the body othernerve cells form plexuses of limited extent.Circulatory system
A plexus is also a network of
blood vessel s, with thechoroid plexus es of thebrain being the most commonly mentioned example. Choroid plexuses are very thin and vascular roof plates of the most anterior and most posterior cavities of the brain which expand into the interiors of the cavities. Other vascular plexuses are found elsewhere in the body.{stub}
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