septum pellucidum

septum

[sep´tum] (L.) 1. a wall or partition dividing a body space or cavity. Some are membranous, some are osseous, and some are cartilaginous; each is named according to its location. See also defect" >septal defect. adj., adj sep´tal.2. nasal septum.alveolar septum interalveolar septum.atrial septum (septum atrio´rum cor´dis) interatrial septum.atrioventricular septum the part of the membranous portion of the interventricular septum between the left ventricle and the right atrium.deviated septum an injury or malformation of the septum" >nasal septum so that one part of the nasal cavity is smaller than the other; this is fairly common and seldom causes complications. Occasionally the deviation may handicap breathing, block the normal flow of mucus from the sinuses during a cold, or prevent proper drainage of infected sinuses. In some cases surgery (called partial or complete submucous resection) may be necessary to relieve the obstruction and reduce irritation and infection in the nose and sinuses.interalveolar septum 1. one of the thin plates of bone separating the alveoli of the teeth in the mandible and maxilla. Called also interradicular septum.2. one of the thin septa that separate adjacent pulmonary alveoli, containing connective tissue and the capillary network of the blood supply of the lung. Defs. 1 and 2 called also alveolar septum.interatrial septum (septum interatria´le cor´dis) the partition separating the right and left atria of the heart; called also atrial septum.interradicular septum interalveolar septum (def. 1).interventricular septum (septum interventricula´re cor´dis) the partition separating the right and left ventricles of the heart; called also ventricular septum.nasal septum a plate of bone and cartilage covered with mucous membrane that divides the nasal cavity.septum lu´cidum septum pellucidum.pellucid septum (septum pellu´cidum) the triangular double membrane separating the anterior horns of the lateral ventricles of the brain; called also septum lucidum.septum pri´mum a septum in the embryonic heart, dividing the primitive atrium into right and left chambers. See also congenital heart defect.rectovaginal septum the membranous partition between the rectum and vagina.rectovesical septum a membranous partition separating the rectum from the prostate and urinary bladder.septum of ventricles of heart (ventricular septum) (septum ventriculo´rum cor´dis) interventricular septum.

sep·tum pel·lu·'ci·dum

[TA] a thin plate of brain tissue, containing nerve cells and fibers, that is stretched like a flat, vertical sheet between the column and body of fornix below, and the corpus callosum above and anteriorly; it is usually fused in the median plane with its partner on the opposite side so as to form a thin, median partition between the left and right frontal horn of the lateral ventricles; in fewer than 10% of humans there is a blind, slitlike, fluid-filled space between the two transparent septa, the cavity of septum pellucidum. The transparent septum is continuous ventrad through the interval between the corpus callosum and the anterior commissure with the precommissural septum and subcallosal gyrus.
See also: cavity of septum pellucidum, septal area. Synonym(s): septum lucidum, transparent septum