ventricle

Ventricle refers to a cavity or chamber within an organ that functions to hold or transport fluid. In anatomy, the term is most commonly associated with the brain and the heart, each having distinct structures and physiological roles.

In the central nervous system, the ventricular system consists of four interconnected cavities filled with cerebrospinal fluid (CSF). The two lateral ventricles lie within the cerebral hemispheres and are linked to the third ventricle, which sits in the midline between the thalami. The third ventricle connects via the cerebral aqueduct to the fourth ventricle, located posterior to the brainstem. CSF produced by the choroid plexus circulates through these ventricles, providing cushioning, waste removal, and nutrient transport for the brain and spinal cord.

In the cardiovascular system, ventricles are the two lower chambers of the heart that receive blood from the atria and pump it forward. The right ventricle receives deoxygenated blood from the right atrium and propels it through the pulmonary artery to the lungs for oxygenation. The left ventricle receives oxygen‑rich blood from the left atrium and generates the high pressure needed to deliver blood through the systemic circulation via the aorta. The muscular walls of the ventricles, especially the left, are thick to accommodate the force required for circulation.

Other biological contexts include the ventricular chambers of certain invertebrates and the ventricle of the eye, a fluid‑filled space behind the lens. Across these varied uses, the defining feature of a ventricle remains a fluid‑containing cavity that plays a crucial role in the movement or regulation of bodily fluids.