7.2 lab - cells of nervous tissue Flashcards Preview

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Flashcards in 7.2 lab - cells of nervous tissue Deck (14)
1

how do many sensory neurons begin?

free nerve endings
-single, bare dendrites sitting in connective tissue or juxtaposed to a basal epithelial cell
-specialized sensory receptors include Meissner's and Pacinian's corpuscles

2

meissner's corpuscle

-tactile corpuscle (light touch sensor)
-mechanoreceptor
-encapsulated by connective tissue
-unmyelenated nerve endings
-horizontal lamellae
-located in dermis very close to epithelial layer
-most frequent in lips and fingertips
-in transverse section looks like a fingerprint

3

pactinian corpuscle

-lamellar corpuscle (pressure/vibration sensor)
-mechanoreceptor
-oval shape with connective tissue and modified schwann cells around fluid filled cavity with a single afferent unmyelenated nerve ending
-located in hypodermis (adipose layer) far from epithelial layer
-in transverse section looks like a sliced onion

4

this stain allow visualization not only of neuron soma but also dendrites and axons

silver stain

5

ventral horn of spinal column

larger butterfly wing in grey matter
ventral root proceeds out from it

6

dorsal horn of spinal column

smaller butterfly wing in grey matter
dorsal root feeds into it

7

why doesn't myelin stain very well?

it is composed of a phospholipid bilayer
lipids do not stain well usually

8

why does it make sense that neuronal cell bodies are so large?

consider the length of axon and dendrites they must support

9

spinal root

dorsal and ventral roots together = spinal root

10

major morphological difference between dorsal and ventral roots?

dorsal root ganglion

11

how to know if spinal section is in vertebra or between vertebrae

spinal roots = probably between?
no roots = probably within vertebra

12

what is a ganglion?

a collection of synapses (neuron soma and axons) outside the CNS (in the PNS)

13

what is difference between nissl & silver stain of nervous tissue?

nissl - soma mostly
silver - soma, axons, dendrites

14

why don't lipids usually stain?

they are usually dissolved in processing