Median Aperture of the Fourth Ventricle

The median aperture of the fourth ventricle (lat. apertūra mediāna ventrículi quartī) is an opening in the medulla oblongata that connects the cavity of the fourth ventricle with the third ventricle.

The median aperture is one of three openings that connect the cavity of the fourth ventricle and the third ventricle. This hole is also known as the Magendie hole.

In its normal form, the median aperture is elliptical and is located at the junction between the medulla oblongata and the pons. Its length is about 5 mm and width 3 mm.

The function of the median aperture is to maintain a balance between the pressure in the fourth ventricle and the third ventricle. When the pressure in the fourth ventricle increases, it is transmitted through the median aperture to the third ventricle, where the pressure decreases.

Malfunction of the median aperture can lead to various diseases, including hydrocephalus, tumors and infections. With hydrocephalus, increased pressure in the fourth ventricle can lead to expansion of the median aperture and disruption of its function. Tumors and infections can also cause the median aperture to malfunction.

Treatment for abnormalities of the median aperture may include surgery, medication, or a combination of these methods. Surgery may involve widening the hole or removing tumors that are preventing it from working properly. Drug therapy may include the use of drugs to reduce pressure in the fourth ventricle or to reduce inflammation in the area of ​​the median outlet.

As I correctly noted, the medium is in the 4th ventricle. Open anteriorly, the middle foramen continues anteriorly from the lateral horn to the cerebellar pyramids and continues dorsally through the midbrain posterior to the midbrain. Posterior to the foramen is the body of the 4th ventricle of the forebrain. This opening contains gray and white matter that runs from the cerebellum to the brainstem and olfactory brain (part of the forebrain) and back. The opening of the 4 ventricles has 3 main leaflets. The largest valve extends from the dorsolateral end of the optic nerve to the brainstem posteriorly and ascends to the midbrain; the anterosuperior lateral ridge descends to the temporoparietal lobe in the semidorsal plane. The other three valves open in approximately the same direction dorsolateral to the first valve and are much smaller, approximately one centimeter long and half a centimeter wide. In the lateral and anteromedial directions, a longitudinal fissure opens between the two valves. The longitudinal fissure extends along the length of the posterior occipital lobe on the posterior wall of the lateral ventricle. The posterior fissure extends from the brain stem to the common occipital nerve of the posterior cerebellar hemispheres. The anterior part of the connection with the writing desk extends to the frontal lobe and subarachnoid space.