Flashcards in Meninges, Ventricular System, CSF Deck (20):
What are the 3 layers of the meninges?
Dura, Arachnoid and Pia maters
Describe the 3 layers of the Dura mater.
1. Periosteal: Closely adhered to the calvarium
2. Meningeal: Forms infoldings
3. Dural border cells
What is the function of the falx cerebri?
Occupies the longitudinal fissure between the hemispheres and encloses the superior sagittal sinus.
Where is the Tentorium cerebelli?
Sits between the cerebrum and posterior fossa
What separates the two cerebellar hemispheres?
What is the main blood supply to the meninges?
Middle meningeal artery
Discuss the Dural venous sinuses
1. Located between the periosteal and meningeal layers of the dura mater.
2. Provide venous drainage for brain with blood and CSF leading into IJV.
3. No valves
Discuss Subdural hematomas
1. Occurs between dura and arachnoid resulting from head trauma.
2. Bridging veins are torn in plane of dural border cells.
Describe the location and characteristics of Arachnoid mater.
1. Between dura and pia
2. CSF located in subarachnoid space
3. CSF flows from the SAS into the dural venous sinuses through the arachnoid villi
Discuss the mechanism of transfer regarding CSF and arachnoid villi
CSF can move through the arachnoid villi intercellularly or mediated transport through cells
Discuss Subarachnoid hemorrhage
Bleeding in the subarachnoid space
Describe the pia mater
A thin layer of CT that closely adheres to the surface of the brain and spinal cord. Also projects into fissures and sulci.
Where are you most likely to find CSF?
Subarachnoid space = 20%
Ventricular system = 80%
Why is CSF important?
Due to the fact that there is no lymphatic system in the brain, it helps remove toxins.
Where is CSF produced?
In the choroid plexus. Lateral ventricles and the roofs of the 3rd and 4th ventricles
How is CSF secreted?
Regulated by a sodium-potassium ATPase. Carbonic anhydrase inhibitors can decrease sodium exchange and thus decrease CSF secretion
Acellular; No rbc or wbc
An enlargement of the ventricles, two types: Communicating and Non-communicating
Discuss Communicating hydrocephalus
Ventricular system communicates with SAS. There is a blockage of CSF resorption in the SAS