Ventricules

Ventricules, or ventricles in English, are hollow chambers in the body that function as pumping or storage spaces in different organ systems. The term comes from the Latin ventriculus, meaning a small belly or cavity. In human anatomy, the most prominent uses are in the brain and the heart.

In the brain, there are four interconnected ventricles: two lateral ventricles in the cerebral hemispheres, a third ventricle in the diencephalon, and a fourth ventricle at the level of the brainstem. These cavities are filled with cerebrospinal fluid (CSF), which is produced mainly by the choroid plexus. CSF circulates from the lateral ventricles to the third via the foramina of Monro, from the third to the fourth via the cerebral aqueduct, and from the fourth ventricle to the subarachnoid space and spinal canal through the foramina of Luschka and Magendie and the central canal. The ventricles help cushion the brain, maintain a stable chemical environment, and remove waste.

In the heart, the ventricles are the two main pumping chambers: the right ventricle and the left ventricle. They are separated by the interventricular septum. The right ventricle receives deoxygenated blood from the right atrium through the tricuspid valve and pumps it to the lungs via the pulmonary artery. The left ventricle receives oxygenated blood from the left atrium through the mitral valve and pumps it to the systemic circulation via the aorta. The left ventricle has a thicker wall due to higher workload. Valves and support structures such as the chordae tendineae and papillary muscles help prevent valve inversion during contraction.