CSF & Ventricular System Part 1 Flashcards
What is foramen Monro?
The lateral ventricles in the deep cerebral hemispheres are connected to third ventricle through the foramen known as foramen monro.
Outside the third ventricle there are thalami on both sides.
Lateral ventricles are present in telencephalon
Thalamic structures are present in diencephalon
The tube coming vertical from third ventricle is the cavity of mesencephalon known as cerebral aqueduct
What is forth ventricle?
From spinal cord the central canal continue upto the mid of medulla, around mid of medulla it expands outward
The expand also coming from top pons side and expand of medulla meet together and made a cavity know as forth ventricle.
This is anterior to cerebellum
What are choroid plexus?
The ventricles contain very specialized structure for the formation of CSF know as choroid plexus
All the cavities within the central nervous system are covered by what??
Ependymal cells
Choroid plexus are made by what??
Telachoridae is the double folded layer of pia matter with the blood vessels and the additional layer of ependymal cells
These All combine to form a secretory unit known as choroid plexus
How CSF is functionally produced from choroid plexus?
There is active secretion of Na+ from epithelial cells of choroid plexus into ventricular cavity
The Cl- is passively secreted followed by sodium
The both NaCl osmotically pull water with them in ventricular cavity due to the increase of osmotic pressure
There is special transport system of glucose too in the epithelial cells but the glucose in CSF is less than the blood. It is about 2/3 of blood glucose
While K+ will be transported back to blood from CSF
So the K+ conc. Will be less in CSF than blood
Which foramen is present laterally on the forth ventricle?
Foramen luschka is present laterally allow the CSF move from brain cavity to outside into cerebellopontine cistern
Which foramen is present on the posterior or median aspect of forth ventricle?
Foramen magendie will leak csf into subarachnoid space and form cerebellomedullary cistern
What are arachnoid villi granulations?
These granulations allow the CSF to move from sub arachnoid space into superior sagittal sinus.
These granules have epithelial caps at the edges they allow CSF to move from sub arachnoid to sinus but don’t allow backward movement.
How much CSF is produced?
Every minute about half ml of CSF is produced
In 24 hrs about 500 ml of CSF is produced
Like about half liter everyday.
Total CSF within brain and outside brain is 130 ml , it means that daily production of CSF is 3-4 time’s then the Total amount of CSF which is present at a given time within and around CNS,
It means constantly produced and constantly drained
