19 terms

AP 13 Brain & Nerves Part 6 - Meninges

Chapter 13 Brain and Nerves Part 6 - Meninges, Bentricles and Cerebrospinal Fluid
connective tissue membranes; Dura mater: superficial, Arachnoid mater: middle, Pia mater: bound tightly to brain; Spaces: subdural, Subarachnoid
Dura Mater
(tough mother) superficial, tightly bound to internal periosteum exept: Falx, cerebri, Tentorium cerebelli, Falx cerebelli, Venous sinuses
Falx Cerebri
in longitudinal fissure between the two cerebral hamispheres
Tentorium Cerebelli
between cerebellum and cerebrum
Falx cerebelli
between 2 cerebellar hemispheres
Venous Sinuses
form at bases of 3 folds - all 3 at base of dura matter
Arachnoid Mater
Thin, wispy layer; looks like spider web; just inferior to dura mater
Pia Mater
thin, delicate CT membrane closely adhered to brain; follows external contours of brain and dips into every sulci and covers every inch of space
Subdral Space
between dura and arachnoid mater; only small amount of serous fluid within; keeps dura and arachnoid from sticking together
Subarachnoid Space
between arachnoid and pia mater; contains web-like strands of arachnoid, blood vessels, and cerebrospinal fluid; contains all nutrients that feed CNS
Blood Supply to Brain
brain requires tremendous amound of blood; receives 15-20% of blood pumped by heart; interruption can cause unconsciousness and irreversible brain damage; receives blood from arteries; Blood brain barrier
High Metebolic Rate w/Blood Supply
dependent upon constant supply of oxygen and glucose
Arteries to Brain
internal carotids and vertebral arteries
Vertebral Arteries to Brain
join to form the basilar artery; usually see anurism with blockage of basilar artery
Carotids to Brain
carotids plus basilar form the cerebral arterial circle (cicle of willis); provides rest of artories to brain
Arteries of Brain Pic
Blood Bain Barrier
3 things that regulate what goes to CNS: 1)endothelial cells (lining all capillaries) have tight junctions between them; 2)Astrocytes have foot processes that influence capillary permeability; 3)Basement membrane of endothelium
Lipid Soluble Sub and Blood Brain Barrier
pass through by diffusion: nicotine, ethanol, heroin
Water Soluble Sub and Blood Brain Barrier
move through mediated (active) transport: amino acids, glucose