lab 1, spcd sensory system histology

Question 1

Pacinian corpuscles

Answer 1

large encapsulated sensory receptor in deep layers of skin, ligaments and joint capsules etc

1-4mm in length and have an appearance of an onion (concentric layers of lamellae of flattened cells- schwann cells) around a core of single large unbranched C fiber, distortion causes AP

Question 2

Meissner corpuscles

Answer 2

small encapsulated receptors- found in glabourous skin, fast adapting detect changes in texture, ovoid collagenous capsule with plump oval cells (schwann cells) and a non myenlinated branch

Question 3

DRG

Answer 3

A bunch f peripheral cell bodies surrounded by satellite cells

Question 4

compare sp cd levels

Answer 4

Sacral: has the least amount of white matter, Fas gracilis is present , Fas cuneatus is absent

Lumbar: large size overall, lateral horn of gray matter is present to L2 level, Fas gracilis is present, but Fas cuneatus is absent

Thoracic: lateral horn of gray matter is present, fasiculus gracilis is present, fas cuneatus is present

Cervical: has the most amount of white matter, oval shape, large anterior horn , FG and FC are both present

Question 5

central gray commissure

Answer 5

surrounds the cerebral canal

Question 6

Lissauer’s tract

Answer 6

finely mylinated axons that activate the posterior horns for dorsal sensation

Question 7

sustantia gelatinosa

Answer 7

the cap of the posterior horn that is pale staining

Question 8

cerebral cortex neuron cell types

Answer 8

olfaction is 3 layers
in humans neocortex (6 layers) is 90% of the cortex

Funtional units are vertical, afferent fibers synapse high in the cortex and the post synaptic neuron cell body in the deep corrtical regions

Efferents come out of pyrimidal cells, that go thru superficial layers