exam 3 day 2

what gives white matter its color

high proportion of myelinated nerve fibers

what does white matter consist of

nerve fibers, (axons), neuroglia, and blood vessels

how is white matter orgnanized

into columns (funiculli); anterior, posterior, lateral

what is a tract (fassiculus)

group of axons with same origins, termination, and function

white matter tracts are divided into what 2 types

ascending (sensory) and descending (motor)

ascending tracts carry info in what direction

to the brain

descending tracts carry info in what direction

from the brain

blue regions are what

ascending (sensory/afferent) pathways

red regions represent what

descending (motor/efferent) pathways

dorsal columns carry what type of info

touch and position (proprioception)

spinothalamic tract carries what

pain and temp

corticospinal tract function

voluntary motor control

what does gray matter consist of

cell bodies, dendrites, neuroglia, blood vessels

shape of gray matter in spinal cord

H-shaped

gray matter is divided into what

horns (posterior, anterior, lateral)

posterior (dorsal) horn function

sensory processing

anterior (ventral) horn function

motor output (skeletal muscle)

lateral horn contains what

preganglionic autonomic neurons

where is the lateral horn found

T1-L2 sympathetic

what connects the two halves of gray matter

gray commisure

what is in the center of gray matter

central canal (CSF)

sensory neuron are located where

dorsal horn

lower motor neurons are located where

ventral horn

interneurons function

connect sensory + motor → reflex arcs

preganglionic neurons are found where

lateral horn

how many Rexed laminae

10

lamina II =

substantia gelatinosa

function of substanta gelatinosa

modulates pain and temp

clarke’s nucleus function

posterior spinocerebellar tracts (proprioception)

clarke’s nucleus location

T1-L3

white matter increases in what direction

caudal→ cranial

why does white matter increase upward

more ascending fibers added

where is gray matter enlarged

cervical and lumbosacral enlargements

why are enlargements present

innervation of limbs

thoracic spinal cord

has lateral horns (ANS)

cervical level

large ventral horns (upper limb)

lumbar level

large ventral horns (upper limb)

thoracic level

small horns + lateral horns present

fasciculus gracilis carries info from

lower limb

fasciculus cuneatus carries info from

upper limb

posterior intermediate sulcus is present where

above T6

lissauer’s tract function

pain fibers enter and ascend / descend slightly

white commissure function

crossing of fibers

what are ventricles

CSF-filled spaces in CNS

lateral ventricles connect to 3rd via

foramen of monro

3rd→ 4th ventricle via

cerebral aqueduct

4th ventricle drains into

subarachnoid space

CSF is produced by what

choroid plexus

CSF composition

low cells, high Na+/Cl-, low K+/Ca2+

csf function

protection

waste removal

ionic balance

largest subarachnoid cistern

cisterna magna

CSF exits 4th ventricle via

foramen of Magendie and Luschka