medulla oblongata

medulla oblongata
pl. medulla oblongatas, medullae oblongatae. Anat.
the lowest or hindmost part of the brain, continuous with the spinal cord. See diag. under brain.
[1670-80; < NL: the long medulla]

* * *

also called  medulla 

      the lowest part of the brain and the lowest portion of the brainstem. The medulla oblongata is connected by the pons to the midbrain and is continuous posteriorly with the spinal cord, with which it merges at the opening (foramen magnum) at the base of the skull.

      Like the cerebrum and cerebellum, the medulla consists of both myelinated (myelin) (white matter) and unmyelinated (gray matter) nerve fibres. In the medulla, however, the normal anatomic relationship of the two is reversed, with the white matter on the outside and the gray matter on the inside, around the fourth ventricle (a fluid-filled cavity formed by the expansion of the central canal of the spinal cord upon entering the brain).

      A complex network of medullary nerve cells and processes from elsewhere in the central nervous system enables the medulla to carry on complex integrative functions. The medulla also contains several functional centres that control autonomic nervous (autonomic nervous system) activity, regulating respiration, heart rate, and digestive processes. Other activities of the medulla include control of movement, relaying of somatic sensory information from internal organs, and control of arousal and sleep.

      The last seven cranial nerves (cranial nerve) emerge from the medulla, which influences their functional activities. Injuries or disease affecting the middle portion of the medulla may produce paralysis of the opposite side of the body, loss of the senses of touch and position, or partial paralysis of the tongue. Injuries or disease of the lateral medulla may cause loss of pain and temperature sensations, loss of the gag reflex, difficulty in swallowing, vertigo, vomiting, or loss of coordination.

* * *


Universalium. 2010.

Игры ⚽ Нужно сделать НИР?

Look at other dictionaries:

  • Medulla Oblongata — Pour les articles homonymes, voir moelle. Vue en 3D de la medulla oblongata (en rouge) …   Wikipédia en Français

  • Medulla oblongata — Pour les articles homonymes, voir moelle. Vue en 3D de la medulla oblongata (en rouge) …   Wikipédia en Français

  • Medulla oblongata — Medulla Me*dul la, n. [L.] 1. Marrow; pith; hence, essence. [Obs.] Milton. [1913 Webster] 2. (Anat.) The marrow of bones; the deep or inner portion of an organ or part; as, the medulla, or medullary substance, of the kidney; specifically, the… …   The Collaborative International Dictionary of English

  • medulla oblongata — [äb΄läŋ gät′ə, äb΄lôŋgāt′ə; äb′läŋgāt′ə, äb΄lôŋgāt′ə] n. [ModL, oblong medulla] the widening continuation of the spinal cord, forming the lowest part of the brain and containing nerve centers that control breathing, circulation, etc.: see BRAIN …   English World dictionary

  • Medulla oblongata — ⇒ Nachhirn …   Deutsch wörterbuch der biologie

  • medulla oblongata — ► NOUN ▪ the part of the spinal cord extending into the brain …   English terms dictionary

  • Medulla oblongata — Brain: Medulla oblongata labeled at bottom left …   Wikipedia

  • Medulla oblongata — Die Medulla oblongata („verlängertes Mark“) ist der hinterste Gehirnteil und gehört zum Hirnstamm und damit zum Zentralnervensystem. Medulla oblongata und Pons …   Deutsch Wikipedia

  • medulla oblongata — noun lower or hindmost part of the brain; continuous with spinal cord; ( bulb is an old term for medulla oblongata) the medulla oblongata is the most vital part of the brain because it contains centers controlling breathing and heart functioning… …   Useful english dictionary

  • Medulla oblongata — The base of the brain, which is formed by the enlarged top of the spinal cord. This part of the brain directly controls breathing, blood flow, and other essential functions. * * * medulla ob·lon·ga·ta .äb .lȯŋ gät ə n, pl medulla oblongatas or… …   Medical dictionary

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”