FOURTH VENTRICLE
- The fourth ventricle is a fluid-filled cavity located in the hindbrain, between the brainstem and the cerebellum.
- It is one of the four ventricles in the brain and plays a crucial role in the circulation & drainage of cerebrospinal fluid (CSF).
- It extends from the cerebral aqueduct superiorly, to the central canal and spinal cord inferiorly.
- It is lined by an epithelial layer called the ependyma.
Shape: Diamond-shaped when viewed in cross-section. tent-shaped when seen from the side.
Boundaries:
- Roof (Dorsall wall):
- ↳ Composed of a thin layer of tissue known as the tela choroidea, wich is continuous with the roof of the 3rd ventricle.
- ↳ Formed by superior medullary velum and inferior medullary velum.
- ↳ band of ependyma stretched btw. the 2 sup. cerebellar puduncles.
- Floor (Ventral wall)
- ↳ Also referred to as the rhomboid fossa.
It is visible into a right and left half by the posterior median sulcus, and into a superior & inferior triangle by the striae medullares.
- Superolateral boundary - formed by the SCP.
- Inferolateral " - " " ICP + gracile & cunate tubrecles
- Lateral walls:
- ↳ Formed by the cerebellar peduncles