The arachnoid or arachnoid mater is the middle layer of the meninges. It acts as a cushion for the neuraxis, also bringing nutrients to the brain and spinal cord and removing waste from the system. Cerebrospinal fluid can be analyzed to make judgments about a person's general health as can blood and saliva. A condition called hydrocephalus occurs when, for some reason, too much cerebrospinal fluid is produced and the ventricles swell, putting pressure on the tissue of the brain.
Choroid Plexus All of the ventricles contain choroid plexuses which produce cerebrospinal fluid by allowing certain components of blood to enter the ventricles. The tentorium cerebelli separates the cerebrum from the cerebellum. The term hydroencephali literally means "water brain" and refers to a rare birth defect in which the cerebrum is absent and the space where it should be is entirely filled with cerebrospinal fluid.
The two foramina of Munro , which are also know as the interventricular foramina , link the lateral ventricles to the third ventricle.
Because space within the cranium is limited, growths or coagulated blood hematoma will displace white and gray matter, pushing them into the ventricular system. Hydrocephalus should not be confused with hydroencephali. The fourth ventricle is connected to the subarachnoid space via two lateral foramina of Luschka and by one medial foramen of Magendie. The anterior horns of these structures are located in the frontal lobes. The Aqueduct of Sylvius which is also called the cerebral aqueduct connects the third and fourth ventricles.
The massa intermedia passes through it and the hypothalamus forms its floor and part of its lateral walls. The falx cerebri separates the hemispheres of the cerebrum. The cerebrospinal fluid of the neuraxis is regenerated several times every twenty-four hours. The Ventricles. Chapter 3. When bleeding occurs in the cranium, blood may collect here and push down on the lower layers of the meninges. If there is hemorrhaging in the brain, blood may collect here.
All blood vessels entering the brain, as well as cranial nerves pass through this space. The meninges are three layers of protective tissue called the dura mater , arachnoid mater , and pia mater that surround the neuraxis. Arachnoid Mater The arachnoid or arachnoid mater is the middle layer of the meninges. The dura mater is the most superior of the meningeal layers. Patrick McCaffrey, Ph. Tumors are one potential cause of an over-production of cerebrospinal fluid.