The four ventricles of the brain are interconnected cavities located within the cerebral hemispheres and brainstem, filled with cerebrospinal fluid (CSF). They are critical components of the ventricular system, which cushions the brain and spinal cord, removes waste products, and helps maintain stable pressure.
The Four Ventricles
Here's a breakdown of each ventricle:
- Lateral Ventricles (Two): These are the largest ventricles and are located within each cerebral hemisphere (left and right). They have several parts:
- Anterior horn (frontal lobe)
- Posterior horn (occipital lobe)
- Inferior horn (temporal lobe)
- Body (parietal lobe)
- Third Ventricle: This ventricle is a narrow cavity located in the midline of the brain, specifically within the diencephalon. The thalamus and hypothalamus form its lateral walls. It connects to the lateral ventricles via the interventricular foramina (also known as the Foramina of Monro).
- Fourth Ventricle: This ventricle is located within the hindbrain, specifically between the pons and the cerebellum. It connects to the third ventricle via the cerebral aqueduct (also known as the Aqueduct of Sylvius). It narrows caudally and is continuous with the central canal of the spinal cord. The fourth ventricle also has three openings, two lateral (foramina of Luschka) and one median (foramen of Magendie), that allow CSF to flow into the subarachnoid space surrounding the brain.
Function of the Ventricles
The ventricles serve as a reservoir for cerebrospinal fluid (CSF), which is produced by the choroid plexus within the ventricles. CSF circulates through the ventricles, carrying nutrients and removing waste. It also cushions the brain and spinal cord, protecting them from injury.
Summary Table
| Ventricle | Location | Connections | Key Features |
|---|---|---|---|
| Lateral Ventricles (2) | Cerebral Hemispheres (Left and Right) | Interventricular Foramina (to 3rd Ventricle) | Largest ventricles; Horns extend into different lobes of the brain |
| Third Ventricle | Diencephalon | Lateral Ventricles (via Interventricular Foramina), Fourth Ventricle (via Cerebral Aqueduct) | Narrow cavity in the midline; Thalamus and Hypothalamus form its walls |
| Fourth Ventricle | Hindbrain (Pons and Cerebellum) | Third Ventricle (via Cerebral Aqueduct), Central Canal of Spinal Cord | Located between the pons and cerebellum; Three openings to the subarachnoid space |
