Lamina terminalis

Lamina terminalis

The lamina terminalis is a thin, vertical membrane located in the brain. It forms the anterior wall of the third ventricle and is situated between the optic chiasm and the anterior commissure. The lamina terminalis is an important structure in the central nervous system and plays a role in various physiological processes.

Anatomy

The lamina terminalis is part of the diencephalon, which is a division of the forebrain. It is positioned at the rostral end of the third ventricle and extends from the rostrum of the corpus callosum to the optic chiasm. The lamina terminalis is bordered by the anterior commissure superiorly and the optic chiasm inferiorly.

Function

The lamina terminalis is involved in the regulation of osmotic pressure and thirst. It contains several important nuclei, including the organum vasculosum of the lamina terminalis (OVLT), which is a circumventricular organ. The OVLT is sensitive to changes in the osmolarity of the blood and plays a crucial role in the body's homeostasis by regulating fluid balance and electrolyte balance.

Clinical Significance

Lesions or damage to the lamina terminalis can result in disturbances in thirst regulation and osmotic balance. This can lead to conditions such as diabetes insipidus or syndrome of inappropriate antidiuretic hormone secretion (SIADH). The lamina terminalis is also a target for certain neurosurgical procedures aimed at treating hydrocephalus and other conditions affecting the ventricular system.

Related Structures

• Third ventricle
• Optic chiasm
• Anterior commissure
• Organum vasculosum of the lamina terminalis
• Diencephalon
• Corpus callosum

See Also

• Central nervous system
• Forebrain
• Homeostasis
• Circumventricular organs