CSF, Meninges and Ventricular System

Cerebrospinal fluid

The fluid that surround the brain and spinal cord
Provides cushioning and protection
Transports nutrients due to having many blood vessels
CSF is continually secreted, circulated and absorbed
Mainly produced in the lateral ventricle and choroid plexus

Choroid plexus

Production site of CSF
A network of vessels in each ventricle in the brain
Produces CSF via ependymal cells that line the ventricles of the brain

Layers (membrane) that cover the brain

Meninges - dura mater, arachnoid mater and pia mater
Collective function of structural and mechanical protection also cellular protection (blood brain barrier)
Support blood vessels and have a high metabolic demand

Dura mater

Outer layer
Loose and not always connected to the skull
Has two layers
Tough

Arachnoid mater

Middle later
Spider like in appearance
Many blood vessels and branches
Under subdura space

Pia mater

Innermost layer
Close to the brain and tightly connected to it

Location of the ventricles of the brain

Lateral ventricle, third ventricle, fourth ventricle and cerebral aqueduct

Lateral ventricle

Largest ventricle located in the cerebrum
One in each hemisphere - within each cerebral hemisphere

Third ventricle

Narrow midline space between the right and left thalamus in the diencephalon
Connected to the lateral ventricle by the foramen of Monro

Fourth ventricle

In the brainstem between the pons and medulla oblongata

Cerebral aqueduct

Connects the third and fourth ventricle

Hydrocephalus

Build up of cerebrospinal fluid in the brain
Excess fluid in the ventricular system which exerts a pressure on the brain which can cause the brain to move down
Due to over production of CSF or it not be drained enough/properly
Could also be caused by bleeding

Hydrocephalus symptoms

Headaches, blurred vision, balance loss, nausea, vomiting, poor coordination

Hydrocephalus treatment

Drainage of fluid either a extra ventricular drain or a VP shunt (internal drain)

Where CSF is absorbed

Through the venous sinus and arachnoid villi