The septum pellucidum is a thin (1.5-3.0mm) transparent membrane that extends from the rostrum, genu and anterior portion of the body of the corpus callosum to the fornix. It separates the anterior horns of the lateral ventricles and has two layers (laminae) that are adherent to each other. The potential space between these two layers is called the cavity of the septum pellucidum (also known as "cavum septum pellucidum" or "cave of septum pellucidum"). This cavity is not continuous with the ventricular system and when referred to as the "fifth ventricle" this is in fact a misnomer. The word "pellucidum" in Latin means transparent. The function of the septum pellucidum is not fully understood 1-4.
The septum pellucidum is lined with ependymal cells on its ventricular side whilst pia mater lines the cavity. It also contains scattered glial cells, nerve fibres and veins 1-2.
The septum pellucidum develops at 10-12 weeks of gestation from the primitive lamina terminalis or the commissural plate. Its development is closely linked with that of the corpus callosum and is complete by 17 weeks of gestation 1.
- 1. Sarwar M. The septum pellucidum: normal and abnormal. AJNR. American journal of neuroradiology. 10 (5): 989-1005. Pubmed
- 2. Mcminn. Last's Anatomy. ISBN: 9780729537520
- 3. Winter T, Toscano MM. Proper latin terminology for the cavum septi pellucidi. AJR. American journal of roentgenology. 197 (6): W1170. doi:10.2214/AJR.11.7152 - Pubmed
- 4. Susan Standring. Gray's Anatomy. ISBN: 9780702068515