Ventricles, Blood, Forebrain Flashcards
Hindbrain consists of what subdivisions?
Metrencephalon & Myelencephalon
Forebrain consists of what subdivisions?
Telencephalon and Diencephalon
Midbrain consists of what subdivisions?
Mesencephalon only
what are 2 fates of CSF?
- central canal down spinal cord
2. leaves via aperatures
where is the choroid plexus located?
in the ventricles
3 purposes of CSF
- float the brain
- positive pressure to absorb shock and prevent organisms form entering
- Chemical stability (provides constant sodium and temperature)
CSF has what concentrations of sodium and potassium?
high sodium and low potassium
Does CSF have protein?
No effin way! No Protein in CSF!!!!!
how much CSF in body? How much is produced each day?
100-150 ml CSF in total - replaced 4x daily
What structures are present in the telencephalon?
Cerebral hemispheres
Lateral Ventricles
3rd ventricle
Basal Ganglia
What structures are present in the Metencephalon?
Pons
cerebellum
part of 4th ventricle
What structures are present in the Mesencephalon?
cerebral aquaduct
red nucleus
substantia nigra
crus cerebelli
What structures are present in the Diencephalon?
Epithalmus Thalmus Hypothalmus Pituitary Pineal Gland Part of 3rd Ventricle Optic cup/nerve
What structures are present in the Myelencephalon?
medulla oblongata
part of 4th ventricle
CSF leave the apertures and goes where?
the subarachnoid space - flows dorsally around the brain
how is CSF removed from around the brain?
Arachnoid granulations come out of the subarachnoid space and into the dural venous sinus- this pushes CSF out into the venous system.
what helps to form the positive pressure in the brain?
choroid epithelial cells form tight junctions
Hydrocephaly
What is it?
2 types?
Hydrocephaly is too much CSF that causes swelling.
- obstructive hydrocephaly - debris can clog the aperatures/ canals
- non-obstructive hydrocephalis - overproduced CSF/ simply can not get rid of it
What is the leptomeninges?
arachnoid matter, subarachnoid space, and pai matter
what blood vessel breaks in a subarachnoid hemmorage?
What occurs?
blood vessel under subarachnoid space breaks - blood is not contained and it diffuses
The middle meningeal artery if ruptured can cause what?
Epidural hematoma- blood fills below skull and pushes meningeal dura down.
Eclipse shape
What causes a subdural hematoma?
Blood from subdural vein(torn bridging central vein) fills below the dura and pushes the arachnoid matter and pia matter in.
-Entire sides can fill in
What are watershed regions?
anastamoses of anterior cerebral/ middle cerebral arteries or the middl cerebral/osterior cerebral arteries
What are projection neurons?
- motor cortex all the way down the brain stem
- spinal cord, basal ganglia, thalmus
what are association fibers?
-connect front to back of individual hemispheres to integrate and associate
What are commissural fibers?
Connect left and right hemispheres, reciprical connections, if cut, the hemisphers function independantly
desussation
cross over of independant tracts at the same site - forms an x
Example of a decussation
projection neurons almost all decussate below the medullary pyramids
Fasciculus
bundle of fibers
Fascicle
bundle
crossing fibers
ill deffined fibers whose principal direction may not be defined- ex trochlear nerve
chiasma
crossing or intersection of two tracts
commissure
union of parts, reciprocal connections
a stoke in the right hemisphere affects what side of the body and why?
A stroke on the right hemisphere will affect the motor of the left side of the body below the decussation
what are fiber tracts?
white matter in the brain
What surrounds the 3rd ventricle?
diencephalon
What 3 parts make up the diencephalon?
- epithalmus
- thalmus
- hypothamus
what is the job of the thalmus
major relay nucleus
What are the names of the tracts as you move from the cortex diencephalon midbrain pons medulla
cortex - corona Radiata diencephalon - internal capsule midbrain-cerebral peduncle pons - corticospinal tract medulla- pyramid
where is the basal ganglion located?
sides of the 3rd ventricle and thalmus
what does parkinson’s disease result from?
the degeneration of neurons in the substantia nigra
what supplies blood to the basal ganglia
internal carotid
what does the basal ganglia do?
It controls willed movement
4 major systems that make up the basal ganglia?
- skeletomotor
- oculomotor
- association - planning, attention
- limbic- affect, motivation, addiction
what is the tailed nucleus in the basal ganglia?
the caudate nucleus
