Histology of the CNS

Question 1

neurons

Answer 1

three regions: soma (cell body), dendrites, axons

Question 2

astrocytes

Answer 2

present in CNS
branching cells w/ cytoplasmic processes ending in expansions called end-feet
end feet cover neurons, inner surface of the pia mater, every blood vessel of the CNS
glia limitans are jointed end feel processes coating the pia mater

Question 3

oligodendrocytes (oligodendroglia)

Answer 3

form the myelin sheaths around the axons in CNS

myelinates multiple axons

Question 4

microglia

Answer 4

resident macrophages of CNS
primary cells to respond to injury to the brain
produce: cehmoattractants
interact w/ astrocytes to modulate the initiation and progression of immune responses
CNS autoimmunity and inflammation
enter from blood

Question 5

ependymal cells

Answer 5

simple cuboidal epithelium

made of ependymal cells and tancytes

Question 6

stroma (cell body)

Answer 6

contains nissl bodies

Question 7

axon

Answer 7

no nissl bodies

Question 8

bipolar neuron

Answer 8

single axon from either side of the cell body

Question 9

pseudounipolar neuron

Answer 9

single axon divides a short distance from the cell body
peripheral branch carriers info from the periphery
central branch ends in the spinal cord

Question 10

multipolar neuron

Answer 10

many dendrites and a single long axon emerges from the cell body

Question 11

pyramidal cell

Answer 11

multipolar neuron

cerebral cortex

Question 12

purkinje cell

Answer 12

multipolar neuron

cerebellar cortex

Question 13

cerebral cortex grey matter layers

Answer 13

molecular layer
external granular layer
external pyramidal cell layer 
internal granular layer 
internal pyramidal cell layer 
multiform cell layer

Question 14

cerebellar grey matter layers

Answer 14

molecular layer
purkinje cell layer
granular layer

Question 15

synapse

Answer 15

1. electrochemical signal reaches axon terminal
2. synaptic vesicles move and bind to docking proteins
3. VG Ca channels open allowing Ca into terminal
4. release of the NT into synaptic cleft

Question 16

axosomatic synapse

Answer 16

axon terminal ending on the soma

Question 17

axoaxonic synapse

Answer 17

axon terminal contacting another axon terminal

Question 18

axodendrtic synapse

Answer 18

axon ending on dendrite

Question 19

axospinous synapse

Answer 19

axon terminal facing a dendritic spine

Question 20

blood brain barrier

Answer 20

tight junctions b/w endothelial cells are the main components
additional components: basal lamina of the endothelial capillaries, perivascular astrocyte end-feet

Question 21

myelination CNS

Answer 21

cytoplasmic processes of adjacent oligodendrocytes do not interdigitate
the space is occupied by an astrocyte end foot process

Question 22

myelination PNS

Answer 22

cyptoplasmic processes of the adjacent Schawann cells interdigitate at the node region

Question 23

epedymal cells

Answer 23

cillia and microvilli and mito (apical)
contact w/ asrocyte (basal)
attached by desmosomes
hold spinal fluid in

Question 24

tanycytes

Answer 24

basal processes extend through the astorcytic process layer to from end feet on BV
attached to each other and to ependymal cells by tight junctions
make spinal fluid

Question 25

chorid plexus

Answer 25

location of production of spinal fluid

ependyma wrapped around fenestrated BV

Question 26

arachnoid - CSF Barrier

Answer 26

arachnoid membrane prevents the CSF into the subarachnoid space from coming in contact c/ the fluid of the extracellular space of the dura
CSF drains around the cerebral hemispheres to the arachnoid villi placed along the venous sinus
NO CSF UP AGAINST DURA MATER

Question 27

blood - CSF barrier

Answer 27

formation of CSF by choroid plexus requires passage of an untrafiltrate of plasma through the fenestrated endothelium of the capillary and CT
choroidal epithelial cells transform this ultrafiltrate into an excretory product

Question 28

meninges

Answer 28

dura mater
arachnoid mater
(subarachnoid space)
pia mater

Question 29

pia mater

Answer 29

single layer of the flat cells on the brain surface

Question 30

arachnoid granulations and arachnoid villi

Answer 30

reabsorb CSF

Question 31

dura mater

Answer 31

tough and collagenous

surrounds the brain and spinal cord

Question 32

arachnoid villi

Answer 32

protrusions of the arachnoid into the lumen of the venous sinus that allows movement of CSF into venous sinus
malfunction leads to hydrocephalus