histo+physio

Question 1

epineurium

Answer 1

surrounds each nerve bundle (of entire nerve)

Question 2

perineurium

Answer 2

surrounds each fascicle of nerve groups

Question 3

endoneurium

Answer 3

surrounds each axon (fiber) > goruped to form fascicle

Question 4

schwann cells

Answer 4

very visible on l/s and prod the myelin for nerve fibers IN PNS

Question 5

nodes of ranvier

Answer 5

facilitate nerve impusle transmission

Question 6

cortex of brain made up of

Answer 6

diffuse arrangement of neurons

Question 7

neuclus is

Answer 7

discrete arrangement of neuronal cells

Question 8

coloumn is

Answer 8

arrangement of cells in spinal cord

Question 9

tract or fascicle is

Answer 9

defined bundle of axons

Question 10

neuroglia

Answer 10

astrocytes
oligodend
microglia
ependymal

supporting cells to the neurons

Question 11

astrocytes char

Answer 11

most common glial cells in grey matter
long branched processes - star shape

processes end on non synaptic areas of neurons OR blood vessels

this termination on blood vessels create BB Barrier

Question 12

astrocytes func

Answer 12

metab exchange bet neuron and blood
regulate int environ of cns

Question 13

types of astrocytes

Answer 13

fibrous- white matter, few STRAIGHT cytoplasmic processes

protoplasmic- grey matter, many BRANCHED processes

Question 14

oligodendrocytes char + func

Answer 14

resp for myelination in CNS
large cells > invest up to 50 axons

smol rond nucl
cyto doesnt stain

Question 15

microglia func + char

Answer 15

smol cells
elong nucl with little cyto
migratory

transform into LARGE MACROPH for protective role

Question 16

ependymal cells char + func

Answer 16

epith like cells that line ventricles
cuboidal or low columnar

tightly bound
NO BM
presence of cilia and microvilli

Question 17

3 layers of grey matter in cblm

Answer 17

PPG
outer- plexiform/molecular layer
middle-purkinjee layer
inner- granular layer

Question 18

plexiform layer of cblm

Answer 18

outer
very few cells, many synapses
contains stellate and basket cells

Question 19

purkinjee layer of cblm

Answer 19

middle
contains hugr purkinjee cells

dendrites transverse molecular layer and reach surface
axons of purkinjee cells are only EFFERENT

Question 20

granular layer of cblm

Answer 20

innner
small dense cells
dark stained nucl

Question 21

purkinjee cell

Answer 21

literally looks like an onion between the granular layer (darker) with dendrites that reach upwards to surface through the molecular layer

Question 22

pyramidal cells

Answer 22

found in cerebral cortex
trianglular
thick branching dendrite that extends to surface

Question 23

appearance of non pyramidal cerebral cortex cells

Answer 23

stellate - star shaped
horizontal - outer layer orientate parr to surface
fusiform - spindle shaped orientated perp to surface
cells of martinotti - small polygonal with few short dendrites

Question 24

excitatory ntrans moa

Answer 24

slight depol by opening na+ channel
leads to na influx
causes excitatory postsynaptic potential to develop ap in axon

Question 25

inhibtory ntrans moa

Answer 25

opening k+ channels in postsynaptic memb
leads to k+ efflux
hyperpol
causing ihibitory postsynaptic potential
ap is not generated

Question 26

inactivation of ntrans mechanisms

Answer 26

diffuses out of synaptic cleft where it has no action
destroyed by specific enzymes
engulfed by astrocytes
reuptake into axon terminal (carrier prot)