Lecture 9: Histology of the Nervous System Flashcards Preview

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Flashcards in Lecture 9: Histology of the Nervous System Deck (22):
1

Ventricular Space

Internal core of CNS, sac filled with CSF, flows into subarachnoid space, lined by ciliated ependymal cells

2

Polarization of Neurons

structurally polarized by axon vs. dendrites; microtubules positive ends towards terminal bouton of axon, negative end towards nucleus

3

Bipolar Neurons

Found in the retina and all cells related to the 8th cranial nerve (auditory)

4

Multipolar neurons

found everywhere

5

unipolar neurons

Found in DRG

6

2 main types of neuron shapes

pyramidal (all have spines) and spiny stellate

7

dendrite spines effected by

experience, learning, memory, cognition, plasticity, hormones and aging

8

amacrine cells

no axon, famously found in retina

9

telodendrons

branching of axons, end in terminal boutons

10

Parts of synapse

presynaptic membrane (of axon, can see vesicles); synaptic cleft; post-synaptic membrane density

11

the neuro-muscular junction

presynaptic membrane very inter-folded with-in the muscle tissue, called junctional folds
Enlarged terminal bouton called end-plate
enlarged synaptic cleft
Synapsing muscle called sole-plate
Differences serve to increase the amount of neuro-transmitter released

12

motor neuron

V. prominent nucleolus, lots of nissl bodies (RER site, needs to make protein for neurotransmitters)
Affected by polio and ALS

13

three types of neuronal cell death

apoptosis (natural/abnormal), necrosis/cytoplasmic (brain trauma), autophagy (auto-immune disease

14

Glia types

astrocytes, oligodendrocytes, microglia

15

Microglia

CNS macrophages, activated by inflammation, can be helpful and harmful

16

Astrocytes

Scavenge neurotransmitters that is leaking, funnel back into neuron; form a lining around the capillary with feet-like processes. All blood vessels in brain covered by astrocyte perivascular end-feet, one astrocyte will cover multiple capillaries

17

oligodendrocytes

Processes of one form myelin sheath for many axons, gaps in myelin sheath create nodes of ranvier, saltatory conduction

18

multiple sclerosis

demyelinating disease of CNS

19

PNS myelination

Supplied by Schwann cells (neurolemmocytes)

20

Schwann cells function

cover all PNS axons, if axon is myelinated will wrap around axon many times creating insulating myelin sheath, nodes of ranvier not insulated but still covered by cell processes

21

neurolemmocytes

another name for schwann cells

22

PNS connective tissue layers

PNS cell --> Schwann cell --> Endoneurium (CT) --> many neurons make up one fasicle/fasiculus -->perineural epithelium --> perineurium (fibrous CT)--> many fasicles make up nerve trunk --> epineurium