Nervous Tissue Flashcards
meninges
specialized covering of the spinal cord and brain (CNS) -dura mater, arachnoid,pia mater
most numerous glial component of the CNS?
astrocytes >>neurons
myelination prevents what?
leakage of membrane charge
principal integrating neurons of the cerebellum
purkinje cells
cerebellar hypoplasia
underdeveloped cerebellum uncoordinated, clumsy
what organelle is in the axon cytoplasm and what does it do?
mitochondria and microtubules; run sodium potassium pump to keep transmembrane potential normal; axonal shape and guide for neurotransmitter molecules
axons are tied together by…
perineurium
myelin producing cell in CNS? PNS?
CNS = oligodendrocyte PNS= schwann cell
epineurium
binds whole nerve fiber together
motor neurons are usually ____; sensory neurons are usually _____
multi polar; bi/pseudouni polar
how is a myelin sheath made?
schwann cell or oligodendrocyte wraps plasma membrane around axon like paper towels up to hundreds of layers with axon at center; nucleus of that cell sits on top of the sheath it made
why is H&E stain less suited for nervous tissue?
high lipid content makes it hard to see structural features
neurons are highly secretory and have lots of ___ and a prominent ___
RER; nucleolus
what is in between each schwann cell?
node of ranvier
what surrounds individual axons?
endoneurium
do the spaces in between the PM in myelin sheath contain cytoplasm?
NO
cerebellum is made of cortex and medulla…what comprises these areas?
medulla = fiber tracts from purkinje cells cortex= surrounds medulla, molecular, purkinje, and granule layers
choroid plexus
secretory structure than makes CSF (cerebral spinal fluid) -capillaries covered with cuboidal epithelium with brush border of microvilli -CSF fills the ventricles of the brain and spinal cord lumen
what increases conduction velocity of nerve processes?
myelination
ventral vs dorsal horns of spinal cord
ventral are larger and motor dorsal are sensory and smaller
axoplasm
axon cytoplasm large oval in it is mitochondrion
osmium tetraoxide stains lipid easily so it stains
myelin sheath –> like dark blue cheerios
in axons of equal size, conduction is higher when…
there is myelin sheath
breaks in myelin sheath
nodes of ranvier
