CSF
What are some of the functions of CSF?
Protection:
Buoyancy: Floats your brain; prevents the brain from hitting skull bone
Provides additional O2 and nutrients
Carriest chemical signals within the brain
What is the name for the infection of dura mater?
Meningitis
What is the difference between a hemorrhage and aneurysm?
Aneurysm: happens when the artery has a weak part in the wall and it balloons out (if it is near the dura you will feel it)
Hemorrhage: weak part in the artery wall pops and blood spills out
What is the function of the BBB?
Selectively pulls out stuff from the blood to protect our neurons, which are sensitive to hormones, water, etc.
How does the Cisterna Magna get its name?
It is located near the foramen magnum
How much CSF is produced daily? Total volume in body? How often is it replaced?
Total volume is 200ml: 600mL produced daily, replaced every 8hrs
What is the difference between true and potential spaces? Give an example for each.
True spaces are supposed to be there (i.e subarachnoid space) and potential spaces are only there if a problem occurs (i.e damage) (subdural/epidural)
What glial cell forms the BBB (Blood-brain barrier)? How do they do this?
Astrocytes; induce tight junction formation
What does a headache indicate?
What cranial nerve is associated?
The dura is irritiated; (dura has nociceptors, activated when stretched); cranial nerve 5 (V)
What is hydrocephalus?
Too much CSF in the lateral ventricles; typically caused by an issue with flow from ventricles into the subarachnoid space.
What glial cell is responsible for the production of CSF?
Ependymal Cells
List the 3 meninges from deep to superficial:
Pia mater (thin, delicate, connected to the cerebral cortex), arachnoid mater (supported to pia mater by trabeculae, makes true space, major blood vessels here), + dura mater (‘tough mother’, double layered, meningeal then periosteal layer (to bone)
What bleed is known as the “worst headache of someone’s life”
Subarachnoid hemorrhage; true space! - blood vessels!
What is the function of a sinus?
Really large floppy vein, where CSF drains, ‘blood collecting area’
What is a CVO? (2 functions)
Circumventricular organs;
BBB is absent for the release of H’s directly into the blood + to detect substances in the blood
What is a cistern? What is the largest + most important cistern?
Cistern: wider region of subarachnoid space; has more CSF
Lumbar Cistern - used for testing
What is the sickle-shaped fold of dura mater that lies in the longitudinal fissure, which is the deep groove that separates the two cerebral hemispheres
Falx cerebelli
What is an epidural hematoma? True or potential space?
Middle meningeal artery hemorrhages and there is blood between skull bone and periosteal dura
How are systemic capillaries different from brain capillaries?
Systemic caps are fenestrated whereas brain caps have tight junctions between endothelial cells
Give a description of each foramena:
Foramen of Monro:
Foramen of Magendie:
Foramen of Luschka:
Monro: Links the 2 lateral ventricles to the 3rd ventricle and to one another
Magendie: medially located aperture in the 4th ventricle
Luschka: Paired L + R lateral apertures that allow CSF to exit the 4th ventricle into the subarachnoid space
What are arachnoid granulations (villi)?
Finger-like extension presses out into the sinus for reabsorption of CSF (one-way valve)
What does the tentorium cerebelli seperate?
The cerebellum + cerebrum
What is a subdural hematoma? True or potential space? Venous or arterial?
Blood pools between the arachnoid mater and meningeal mater (venous) (bridging veins)
What is the flow of CSF? What structure produces it?
Made in lateral ventricles, goes into 3rd ventricle (made here too), into cerebral aqueduct (none made here), into 4th ventricle (made here)
What is the Area Postrema?
Area Postrema: barf center; chemotoxic trigger zone, medulla detects what is in the blood