Definition of Third ventricle
Third ventricle: One cavity in a system of four communicating cavities within the brain that are continuous with the central canal that contains the spinal cord. The third ventricle is a median (midline) cavity in the brain and is bounded by the thalamus and hypothalamus on either side. It communicates anteriorly (in front) with the lateral ventricles, and posteriorly (in back) with the aqueduct of the midbrain, also known as the aqueduct of Sylvius. All the ventricles are filled with cerebrospinal fluid, which is formed by choroid plexuses, structures that are located in the walls and roofs of the ventricles.Source: MedTerms™ Medical Dictionary
Last Editorial Review: 3/19/2012
Medical Dictionary Definitions A - Z
Search Medical Dictionary
Brain and Nervous System Resources
- How Well Are You Living With AFib?
- How Well Are You Managing Your MS?
- Soothe Your Child's Cold or Flu