Plexus

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 neurons join together to form a plexus or nerve net.

In vertebrates

In vertebrates, a plexus is an area where nerves branch and rejoin, for example the brachial plexus made up of the spinal nerves which enter the arm and the solar plexus above the stomach.

Almost a hundred such plexuses have been named in the human body, but the four primary nerve plexuses are the cervical plexus, brachial plexus, lumbar plexus, and the sacral plexus.

In invertebrates

Plexuses is the characteristic form of nervous system in the coelenterates and persists with modifications in the flatworms. The nerves of the radially symmetric echinoderms also take this form, where a plexus underlies the ectoderm of these animals and deeper in the body other nerve cells form plexuses of limited extent.

Circulatory system

A plexus is also a network of blood vessels, with the choroid plexuses of the brain 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.

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  • PLEXUS — Ensemble de carrefours anatomiques constitués par l’entrecroisement de plusieurs rameaux nerveux ou par l’interconnexion de troncs vasculaires. plexus [ plɛksys ] n. m. • 1541; mot lat. « entrelacement », de plectere « tresser » ♦ Anat. Réseau de …   Encyclopédie Universelle

  • Plexus — (vom lateinischen plectere, flechten) bezeichnet: ein Netzwerk das Adern , Lymphgefäß oder Nervengeflecht in der Medizin, siehe Plexus (Medizin) eine Zeitschrift für Personal aus den Bereichen Anästhesie und Intensivbehandlung, siehe Plexus… …   Deutsch Wikipedia

  • Plexus — Plex us, n.; pl. L. {Plexus}, E. {Plexuses}. [L., a twining, braid, fr. plectere, plexum, to twine, braid.] 1. (Anat.) A network of vessels, nerves, or fibers. [1913 Webster] 2. (Math.) The system of equations required for the complete expression …   The Collaborative International Dictionary of English

  • Plexus — Plex us, n.; pl. L. {Plexus}, E. {Plexuses}. [L., a twining, braid, fr. plectere, plexum, to twine, braid.] 1. (Anat.) A network of vessels, nerves, or fibers. [1913 Webster] 2. (Math.) The system of equations required for the complete expression …   The Collaborative International Dictionary of English

  • plexus — [plek′səs] n. pl. plexuses or plexus [ModL < L, a twining, braid < pp. of plectere, to twine, braid; akin to plicare: see PLY1] 1. a complexly interconnected arrangement of parts; network 2. Anat. a network of blood vessels, lymphatic… …   English World dictionary

  • plexus — [ pleksəs ] see SOLAR PLEXUS …   Usage of the words and phrases in modern English

  • plexus — (n.) 1680s, Modern Latin, lit. braid, network, from pp. of L. plectere to twine, braid, fold (see COMPLEX (Cf. complex) (adj.)); used of a network, such as solar plexus network of nerves in the abdomen (see SOLAR (Cf. solar)) …   Etymology dictionary

  • PLEXUS — PLEXUS, • сплетение, анат. понятие, относящееся к периферическим отделам нервной, кровеносной и лимф, систем в тех случаях, когда между стволами нескольких соответствующих нервов или сосудов в определенных, б. или м. ограниченных, участках… …   Большая медицинская энциклопедия

  • Plexus — (lat.), Geflecht, d. i. eine Verbindung, welche das Ansehen von Verflochtenem hat, von Gefäßen, bes. venösen u. lymphatischen, u. von Nerven, s. u. Gehirnnerven, Gangliennerven etc …   Pierer's Universal-Lexikon

  • Plexus — Plexus, s. Geflecht …   Meyers Großes Konversations-Lexikon

  • Plexus — (lat.), Geflecht, Verbindung zweier oder mehrerer parallel laufender Blut (Adergeflecht) oder Lymphgefäße oder Nerven zu einem Netz. (S. Nervengeflecht, Sonnengeflecht) …   Kleines Konversations-Lexikon

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