Day 3 - 5/30 Flashcards
Dura mater
tough outer layer, keeping ventricle in place by skull and vertebral column
makes sure hemispheres do not bump
What is the point of a sinus?
“Storm sewer” - points at which used up fluid goes back to heart
What are the names of the two divisions when the dura mater outer layer splits?
falx cerebri (longitudinal fissure) and tantrum cerebelli
Where is the falx cerebri and fx?
in the longitudinal fissure
ensures the two hemispheres will not bump
Where is the tantrum cerebelli and fx?
cushions cerebellum over entire top of cerebellum
What is the order of the meninges from outside in?
dura –> arachnoid (subarachnoid) –> pia mater
Describe the arachnoid mater and fx.
contains a subarachnoid space where CSF actually circulates.
Villi poke through arachnoid into the superior sagittal sinus with tiny granulations for CSF to drain
What is Pia mater and fx?
very thin layer of connective tissue between arachnoid mater and NS. Closely to brain and SC.
What is CSF?
Similar to plasma of blood but without elements
Describe the circulation from heart and back to heart of CSF.
begin: heart –> ventricles 1 & 2 (always goes through choroid plexus in each ventricle to remove formed elements) –> interventircular foreamen –> third ventricle –> cerebral aqueduct –> fourth ventricle –> 2 lateral and 1 median foreamen –> subarachnoid space –> villi –> granulations –>superior sagittal sinus –> reabsorbed into blood stream through jugular vein –> end: heart
Hydrocephalus
Cerebral aqueduct gets squeezed – ventricles swell – cells shrink – eventually die if continually squeezed between CSF pathway and bone
Meningitis
penetrates dura mater and outer meninges –> inflammation –> extra CSF –> squeezing –> gets through pia mater and attacks NS cells of outer brain
Where does the underneath of the temporal lobe, occipital lobe and all of brainstem get blood supply from?
Posterior
Where does the frontal lobe, top of temporal and parietal get blood supply from?
Anterior
Describe the blood circulation of the anterior supply
aortic arch >vertebral Aa- in front of medulla > posterior inferior cerebellar A > vertebral Aa connect to form basilar A before pons > anterior inferior cerebellar A > anterior superior A > basilar splits into 2 at top of pons> posterior superior A
Describe the blood circulation of the posterior blood supply
internal carotid > splits into anterior and middle cerebellar Aa
Anterior - longitudinal fissure and supplies med. surface of frontal/parietal and limbic lobe
Middle - goes lateral and supplies lateral frontal/parietal and lateral/top of temporal
