Histology of CNS

Question 1

What is something that is unique to neurons, that can be found within their cell body?

Answer 1

Nissl substance/bodies

Question 2

What is the importance of Nissl substance/bodies?

Answer 2

The stained speckles = ribosomes; It is indicative of their protein synthesis and thus, metabolic activity of the neuron

Question 3

Can the spines on a dendrite change?

Answer 3

Yes, spines are plastic and will increase their amount if the area is highly receptive. Will also decrease their amount of the area is inactive.

Question 4

What is a neuropil?

Answer 4

Network of nerve fibers and their branches together with glial processes

Question 5

What is the correct term for the typical neuron?

Answer 5

Multipolar neuron

Question 6

What type of neuron has the cell body in the middle and an equal amount of dendrites on each side?

Answer 6

Bipolar neuron

Question 7

How do you tell which side of the bipolar neuron is the axon?

Answer 7

Direction of signal propagation

Question 8

Where would you find bipolar neurons?

Answer 8

Retina

Question 9

Describe the organization of a unipolar neuron

Answer 9

A cell body with single short process, a peripheral process that is longer than the central process
The peripheral process houses the dendrites
The axon includes the peripheral and central processes

Question 10

What is a unipolar neuron used for?

Answer 10

Sensation

Question 11

What type of neuron has no axons and thus no signal conduction?

Answer 11

Anaxonic neuron

Question 12

What protein do gap junctions use in an electrical synapse?

Answer 12

Connexin

Question 13

What are the types of synaptic transmission?

Answer 13

Axodendritic
Axosomatic
Axoaxonic

Question 14

Main function of astrocytes?

Answer 14

Establish blood-brain barrier

Question 15

What special property helps stain the astrocytes?

Answer 15

GFAP (glial fibrillary acid protein)

Question 16

Main function of ependymal cells?

Answer 16

Facilitate CSF movement! Removes H2O from blood and releases as CSF

Question 17

What type of cells are ependymal cells?

Answer 17

Simple cuboidal/columnar

Question 18

What makes up the choroid plexus

Answer 18

Pia mater + ependymal cells

Question 19

Main function of microglia?

Answer 19

Remove damaged/inactive synapses and microbial invaders - immune response

Question 20

What do microglia originate from?

Answer 20

Monocytes

Question 21

Function of oligodendrocytes?

Answer 21

Enwrap axons from MULTIPLE neurons with myelin

Question 22

What are CNS cell types?

Answer 22

Astrocytes, ependymal cells, microglia and oligodendrocytes

Question 23

Where are astrocytes, ependymal cells and oligodendrocytes derived from?

Answer 23

Neural tube

Question 24

What are the peripheral glial cells?

Answer 24

Neurolemmocytes (schwann cells) and Satellite cells

Question 25

Where are peripheral glial cells derived from?

Answer 25

NCC

Question 26

Function of Neurolemmocytes?

Answer 26

Myelinate peripheral nerves

Question 27

Function of Satellite cells?

Answer 27

Structural and metabolic support for neuronal cell bodies

Question 28

Where will you find satellite cells?

Answer 28

Dorsal root ganglion (DRG)

Question 29

Difference between oligodendrocytes and Neurolemmocytes?

Answer 29

Neurolemmocytes only myelinate ONE axon, while oligodendrocytes can wrap multiple

Question 30

How many layers are in the neocortex in the cerebral cortex?

Answer 30

6

Question 31

What are the layers of the neocortex from superficial to deep?

Answer 31

``` Molecular layer External granular layer External pyramidal layer Internal granular layer Ganglionic layer Multiform (polymorphic) layer ```

Question 32

What distinguishes the molecular layer?

Answer 32

Low amount of cell bodies

Question 33

What distinguishes the ganglionic layer?

Answer 33

Large pyramidal shaped cells - used in motor areas

Question 34

What distinguishes the multiform (polymorphic layer)?

Answer 34

Diverse cell body shapes

Question 35

What is the oldest layer in the neocortex?

Answer 35

Multiform (polymorphic) layer

Question 36

What accumulates abnormally in the cortex of a patient with Alzheimers?

Answer 36

Amyloid beta plaques and tau protein (neurofibrillary tangles)

Question 37

What shape are tau proteins?

Answer 37

Flame

Question 38

What is included in the neurons of a patient with Parkinson's?

Answer 38

Lewy bodies

Question 39

What do lewy bodies look like and what is within them?

Answer 39

Round, pink staining with a pale halo; alpha-synuclein protein is within

Question 40

What degenerates in patients with Parkinsons?

Answer 40

Substantia nigra

Question 41

Describe the substantia nigra

Answer 41

Mass of gray matter that is important in the control of motor function; contains multipolar neurons with neuromelanin pigment

Question 42

What does the neuromelanin pigment contain?

Answer 42

Dopamine

Question 43

Function of dopamine?

Answer 43

Inhibitory effects in brain areas dedicated to movement

Question 44

What are the 3 layers of the cerebellar cortex from superficial to deep?

Answer 44

Molecular layer Purkinje cells Granular layer

Question 45

Scattered neuronal cell bodies and lots of neuropil; what layer in the cerebellar cortex?

Answer 45

Molecular layer

Question 46

Densely packed neuronal cell bodies and little neuropil; what layer in the cerebellar cortex?

Answer 46

Granular layer

Question 47

How thick is the purkinje layer of the cerebellar cortex?

Answer 47

1 cell thick

Question 48

How can you tell where the anterior horn of the spinal cord is?

Answer 48

It is grey matter and it contains cell bodies for motor neurons

Question 49

Describe the organization of peripheral nerves

Answer 49

1 axon encircled many times by 1 schwann cell whose cytoplasm and nucleus are squished to the outer layer

Question 50

Are unmyelinated axons still interacting with schwann cells?

Answer 50

Yes; many unmyelinated axons will still have 1 schwann cell that tries to surround each axon just once

Question 51

What is immediately surrounding the neurolemmocytes?

Answer 51

Endoneurium

Question 52

What enwraps fasicles?

Answer 52

Perineurium

Question 53

What enwraps all of the fasicles and surrounds the peripheral nerve?

Answer 53

Epineurium