The septum pellucidum, also called the septum lucidum, is a thin, triangular, vertical membrane that separates the lateral ventricles of the brain. The ventricular system is a fluid conducting system within the brain. ... In the anatomy of animals, the brain, or encephalon, is the supervisory center of the nervous system. ...

The septum pellucidum actually consists of two layers or laminae of both white and gray matter, called the laminae septi pellucidi. These layers are normally fused; however, in approximately one-tenths of humans, there is a slit-like cavity between them. This space is occasionally called the fifth ventricle, although is usually not continuous with the ventricular system and does not contain cerebrospinal fluid. White matter is one of two categories of tissue in the nervous system. ... Grey matter is a category of nervous tissue with many nerve cell bodies and few myelinated axons. ... Cerebrospinal fluid (CSF) is a clear bodily fluid that occupies the subarachnoid space in the brain (the space between the skull and the cerebral cortex—more specifically, between the arachnoid and pia layers of the meninges). ...

The septum pellucidum is located in the midline of the brain, between the two cerebral hemispheres. It is attached superiorly (above), anteriorly (in front), and inferiorly (below) to the corpus callosum, the large collection of nerve fibers that connect the two hemispheres. Inferiorly and posteriorly (in back), it is attached to the anterior part of the fornix. On either side are the two lateral ventricles, pockets of cerebrospinal fluid within the cerebral hemispheres. Human brain viewed from above, showing cerebral hemispheres. ... In human and zoological anatomy (sometimes called zootomy), several terms are used to describe the location of organs and other structures in the body of bilateral animals. ... The corpus callosum is the largest white matter structure in the mammalian brain. ... Categories: Medicine stubs | Central nervous system ...

Absence of the septum pellucidum or corpus callosum, caused by mutations in the HESX1 gene, is associated with septo-optic dysplasia. This may result in hypothalamic dysfunction and hypopituitarism, as well as problems of vision, coordination, and intelligence, among other abnormalities. Mutations are permanent, sometimes transmissible (if the change is to a germ cell) changes to the genetic material (usually DNA or RNA) of a cell. ... This stylistic schematic diagram shows a gene in relation to the double helix structure of DNA and to a chromosome (right). ... Septo-optic dysplasia (SOD) is a congenital malformation syndrome manifested by hypoplasia (underdevelopment) of the optic nerve, hypopituitarism, and absence of the septum pellucidum (a midline part of the brain). ... In the anatomy of mammals, the hypothalamus is a region of the brain located below the thalamus, forming the major portion of the ventral region of the diencephalon and functioning to regulate certain metabolic processes and other autonomic activities. ... Hypopituitarism is a medical term describing deficiency (hypo) of one or more hormones of the pituitary gland. ...

One famous reference to an abnormality of the septum pellucidum would be the movie Rocky V. In the movie, the main character Rocky Balboa is forced to retire due to brain damage sustained throughout his career. Rocky V DVD cover Rocky V is the last of the Rocky sequels. ... Rocky DVD cover Rocky is a motion picture released in 1976 starring Sylvester Stallone as Rocky Balboa and Carl Weathers as Apollo Creed. ...

References

• Gray, Henry & Clemente, Carmine D. (1984). Gray's Anatomy of the Human Body (30th ed.). New York: Lippincott Williams & Wilkins.

• Kasper, Dennis L.; Braunwald, Eugene; Fauci, Anthony S.; Hauser, Stephen L.; Longo, Dan L.; Jameson, J. Larry; & Kurt J. Isselbacher, (Eds.) (2004). Harrison's Principles of Internal Medicine (16th ed.). New York: McGraw-Hill.