transparent 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

trans·par·ent sep·tum

(trans-par'ĕnt sep'tŭm) A thin plate of brain tissue, containing nerve cells and numerous nerve fibers, that is stretched like a flat, vertical sheet between the column and body of the 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 horns 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 ventralward through the interval between the corpus callosum and the anterior commissure with the precommissural septum and subcallosal gyrus.