NS 2 - Histology

Question 1

What is Axoaxonic type of neuron?

Answer 1

excitatory or inhibitory, increase or decrease neurotransmitter release by postsynaptic terminal

Question 2

what is axospinous type of neuron?

Answer 2

excitatory synapses

Question 3

What is axodendritic type of neuron?

Answer 3

excitatory or inhibitory synapses

Question 4

What is axosomatic type of neuron?

Answer 4

excitatory or inhibitpry synapses

Question 5

What is an axonal varicosity?

Answer 5

Bead like terminal on axon that releases neurotransmitter

Question 6

Sensory/Pseudo-unipolar neuron

Answer 6

touch, pain, taste (ganglion)

Question 7

motor neuron

Answer 7

spinal cord (anterior horn), brain stem (cranial nerve motor nucleus)

Question 8

local interneuron

Answer 8

very short, unmyleinated axons of CNS/PNS

Question 9

Neuroendocrine

Answer 9

hypothalamus, releases peptide hormones (systemic or portal) typically to capillary

Question 10

Kinesin function of axonal transport

Answer 10

anterograde, to positive terminal or positive dendrite end

Question 11

Dynein function of axonal transport

Answer 11

retrograde, toward soma, negative end

Question 12

Clinical significance of axonal transport

Answer 12

viruses spread in peripheral neuropathies, some viruses such as rabies can jump across synapses

Question 13

Schwann cells and ogliodendrocyte for conduction of AP

Answer 13

myelin sheath has gaps which are nodes of ranviers where sodium channels are for allowing AP

Question 14

What is the mechanism of action for demyleination diseases/disorders?

Answer 14

ineffective proteins between the multiple lipid bilayers, degradation of Myelin Basic Protein and Peripheral Myelin Protein 22 are key targets

Question 15

Axonal injury

Answer 15

NOT demylienation but actual injury. Can regrow but can’t take itself to CNS/PNS
Anterograde is distal to injury
Schwann cells are scaffolding and protection for regeneration

Question 16

Schwann cells in PNS with axonal injury

Answer 16

macrophages clean up yucky injury area but schwann cells are what create favorable environment for re-growth
Much better regrowth

Question 17

Ogliodendrocytes in CNS with axonal injury

Answer 17

monocytes turn to microglia to clean up debris but still problems
Oglios like to die off as easily damaged and create scar tissue

Question 18

peripheral neuropathy

Answer 18

demyelination axons in peripheral
slows electrical conduction/sensory process/muscle weakness
speed of conduction key to show demyelin not axonal (signal amplitude)

Question 19

causes of peripheral neuropathy

Answer 19

autoimmune, typically causes change in action potential and connection with peripheral nerves

Question 20

MS

Answer 20

attack against myelin sheath CNS azons, creates 2+ focal lesions

Question 21

B12 deficincy

Answer 21

can develop due to alcohol abuse causing problem with PNS nerves on CNS axons

Question 22

Glial Cells

Answer 22

ogliodendrocytes (CNS), schwann cells (PNS), microglia, astrocytes, ependymal cells

Question 23

Microglia

Answer 23

immune surveillance CNS, attack invading pathogens

Question 24

astrocytes

Answer 24

play role in BBB by keeping normal extracellular environment or supplying molecules to neurons regulate synaptic function

Question 25

ependymal cells

Answer 25

form single layer along deepest border between tissue and CSF cavity

Question 26

Microglia in microscopy

Answer 26

small, flat bodies in resting state
some traumatic event causes them to synthesisze material and release info which creates expanded size in active state

Question 27

auto immune disease microglia

Answer 27

something triggers inappropriate inflammation where prevent self recognition and react to CNS antigen as foreign

Question 28

Astrocytes

Answer 28

multiple function with many dendrites, they gather together at site of inflammation or injury to create impenetrable barrier to prevent spread

Question 29

Astrocytes 3 main location

Answer 29

barrier just inside pia layer
BBB & surrounding capillaries
envelope part of neuron to control extracellular environment for normal neuron

Question 30

Astrocyte 3 parts in barrier making

Answer 30

astrocyte barriers have non-fenestrated tight junctions, mean completely impenetrable
pericytes are involved by moving substance across membranes
astrocytes extend feet around pericyte

Question 31

astrocyte and BBB

Answer 31

lipid/hydrophobic diffuse spontaneous across BBB (steroid & hormones)
water soluble can’t diffuse BBB, need active transport (glucose, amino acids, nucleotides)
medications sometimes need alterations to be able to use active transport

Question 32

white matter contents

Answer 32

myelinated axons

Question 33

gray matter contents

Answer 33

cell bodies & dendrites, few or none axons

Question 34

Anterior/ventral roots carry what axons?

Answer 34

motorneurons project to skeletal

Question 35

dorsal/posterior roots carry what axons?

Answer 35

sensory neurons that have cell bodies in dorsal/posterior ganglion

Question 36

what do peripheral nerves carry?

Answer 36

axons of sensory, motor, and autonomic neuronsas

Question 37

sensory ganglions pathway

Answer 37

sensation: skin, conective tissue, bone, joint, muscle, tendon, visceral organ
Synapse: in spinal cord, brain stem
Doesn’t have synaptic connection, bypass go one end to next

Question 39

Sympathetic chain

Answer 39

from T1-L2 of spinal cord, then synapse paravertebral and project on to further target

Question 40

parasympathetic ganglion

Answer 40

from brainstem or S2-S4 spinal cord then synapse on parasympathetic ganglion near target, project onto nearby target