opened channels are readjusting to their closed position and will not respond to further stimuli
how brain receives qualitative data from incoming signals?
labeled line code
how brain receives quantitative data from incoming signals?
change in frequency of signal
recruitment of higher threshold neurons
isolation of strongest signal
dura mater- thick out covering, splits to form venous sinuses in the brain
arachnoid- thin middle layer, enclose the CSF
pla mater- adherent covering of the brain and cord, forms anchor for the cord
spinal cord anatomy?
cervical and lumbar enlargements
dorsal and ventral horns
dorasal root gnaglion
spinal cord anatomy details?
1) extra nerves for arms and legs
2) areas of the cord where sensory fibers enter (dorsal) and motor fibers exit (ventral)
3) collection of sensory nerve cell bodies just before entering the cord
4) posterior coninuation of the 4th ventricle through the middle of the cord
5) the tapered end of the cord
6) spinal nerves in the vertebral canal below the conus (below L1)
7) a filament anchoring the conus to the coccyx, formed by the pia mater
describe the circulation of the cerebrospinal fluid?
made by the choroid plexus in the lateral ventricles > third ventricle > cerebral aqueduct > 4th ventricle >around the brain and cord in subarachnoid space > back to the blood stream at the superior sagittal sinus
function, decussation and destination of dorsal columns?
vibration, discriminative touch, proprioception- crosses medulla, goes to thalamus
function, decussation and destination of spinothalamic tract?
pain, temperature, pressure, light touch,- crosses at entry level, goes to thalamus
function, decussation and destination of spinocerebellar tract?
proprioception- does not cross, goes to cerebellum
function, decussation and destination of corticospinal tract?
main motor nerves- crosses in medulla, goes to skeletal muscles
function, decussation and destination of reticulospinal tract?
maintains posture and balance- does not cross, goes to skeletal muscles
function, decussation and destination of tectospinal tract?
causes reflex turning of the head- crosses in the midbrain, goes to muscles of the head and neck
function, decussation and destination of vestibulospinal tract?
maintains balance and control of head position- fibers for the head control cross in the medulla, goes to the skeletal muscles
what are the named areas of gray matter in the brain?
anatomy of a spinal nerve?
dorsal (sensory) and ventral (motor) roots from the cord join
leave the vertebral canal
split into dorsal and ventral branches (both mixed)