Histology - Test 2 - Nerve

Front 1

Where are the cell bodies for the ANS and processes for the ANS>

Back 1

Cell bodies- in the CNS

Processes - PNS

Front 2

What does ectoderm give rise to?

Back 2

suface ectoderm, neural tube, and neural crest

Front 3

What does the neural crest cells create?

Back 3

components of the PNS - Schwann cells, sympathetic and parasympathetic systems, suprarenal medualla, melanocytes, odontoblasts, neuroglial cells

Front 4

What are the supporting cells called in the CNS and PNS?

Back 4

CNS = neuroglia

PNS - Schwann and satellite cells

Front 5

What is the gray matter?

Back 5

neuron cell bodies and neuroglia

Front 6

What is in the white matter?

Back 6

neuronal processes and neuroglia

Front 7

What is in a ganglia?

Back 7

neuron cell bodies, Schwann, and satellite cells

Front 8

Where is the only place you find a nerve cell body in the PNS?

Back 8

in the ganglia

Front 9

What are nissl bodies?

Back 9

stacks of rER - function is to produce neurotransmitter substance

Front 10

Where in the cell lacks nissl substance? Why?

Back 10

The axon hillock -- no nissl bodies because cytoskeletal elements take up all the space

Front 11

How do axons branch? what are they called?

Back 11

usually at 90 degree angles -- the branches are called collaterals

Front 12

What does the axon nerve contain?

Back 12

ribosomes

Front 13

Are dentrites myelinated?

Back 13

Rarely -

Front 14

What is along the length of the dendrite?

Back 14

dendritic spines

Front 15

What does the dendrite contain?

Back 15

microtubules

Front 16

What is the cytoskeleton made out of in the dendritic spines?

Back 16

actin only

Front 17

Name the types of neurons?

Back 17

bipolar, multipolar, pseudounipolar

Front 18

What are each of the types of neruons used for?

Back 18

Bipolar - special sense
Multipolar- motor
Pseudounipolar - sensory and dorsal root ganglia

Front 19

Why is the post synaptic face easier to identify?

Back 19

because of the thickening of the cell membrane

Front 20

What is the presynaptic face full of?

Back 20

synaptic vesicles

Front 21

What are the type of synapses/

Back 21

1. Axosomatic
2. Axoaxonic
3. Axodendredic
4, Axospinous - an axon endding on a den dritic spine

Front 22

Which synapse is most common?

Back 22

axodendritic synapse

Front 23

What is the dendritic shaft full of?

Back 23

microtubules and a little actin

Front 24

Where is the Schwann cell cytoplasm?

Back 24

predominantly located along the outer aspect of the myelin sheath

Front 25

What are the external and internal mesoaxon?

Back 25

Internal - The original site of invagination

External - the external gap where the 2 myelin's meet

Front 26

What is the portion of the neuronal process wrapped by a single Schwann cell?

Back 26

an internode

Front 27

What are the Nodes of Ranvier?

Back 27

The naked gaps between myelinated segments

Front 28

What are Cytoplasmic clefts that appear within the myelin sheath?

Back 28

clefts (incisures) of Schmidt-Lanterman

Front 29

What does a schwann cell myelinate?

Back 29

one segment of 1 neuronal process

Front 30

What is the major dense line?

Back 30

where the 2 inner leaflets are close (has a little cytoplasm inbetween)

Front 31

What is the intraperiod line?

Back 31

the two outer leaflets meet - extracellular space in between

Front 32

What can an oligodendrocyte mylinate?

Back 32

more that 1 process -- each process off the cell myelinated 1 internode of the axon

Front 33

What is a difference between the myelin from a Schwann cell and an oligodendrocytes?

Back 33

Schwann -- uses Myelin Protein Zero

Oligodendrocyte-- uses Proteolipid Protein

Front 34

What are Myelin Protein Zero adn Proteolipid protein used for?

Back 34

Glue -- attaches the myelin to its plasma membrane. Stabilizes the several layers of myelin

Front 35

What is the conduction called where it jumps from node to node?

Back 35

Saltatory conduction

Front 36

What type of axons, myleinated or not, is more effecientally metabolically?

Back 36

Myelinated - dont have have to have Na pumps all along the axon - just at the internodes

Front 37

Where is the cytoplasm in a schwann cell?

Back 37

1. adjacent to the axon (inner colar
2. between the lamellae( clefts of Schmidt Lantermann
3. paranodal areas
4. outer collar

Front 38

What is the purpose of the incisures of Schmidt Lanterman?

Back 38

to keep the inner and outer collar connected with cytoplasm

Front 39

What are unmyelinated axons surrounded by in the PNS?

Back 39

A schwann cell and a basal lamina surrounding the Schwann cell

Front 40

Where can you find mesaxons?

Back 40

In both mylinated and unmylinated axons

Front 41

When does unmyelination happen?

Back 41

When the axon doesnt have the code for myelination

Front 42

What are the two possibilities for the fate of a Schwann cell?

Back 42

1. Can only surround 1 cell and myelinate it

2. Can support several unmylinated axons

Front 43

What is the fuzzy layer that surrounds each schwann cell called?

Back 43

the endoneurium

Front 44

What are the layers that cover a nerve?

Back 44

1. epineurium- outer covering, surrounds the entire nerve- contains blood vessels, ect
2. perineurium - ct that wraps groups of nerve fibers into bundles (fascicles)
3. endoneurium - wraps around individual neuronal processes

Front 45

What is the endoneurium secreted by?

Back 45

by fibroblasts within the peripheral nerve

Front 46

What are the 3 types of neuroglia cells?

Back 46

1. Astrocytes
2. Microglia
3. Ependymal Cells
4. Oligodendrocytes

Front 47

How many neuroglial cells are to each neurons?

Back 47

5- 10

Front 48

What does an astrocyte do?

Back 48

It is a packing cell - packs the space so that everything is held together

Front 49

What establishes the blood brain barrier?

Back 49

Perivascular feet

Front 50

What does the end feet of the astrocytes cover?

Back 50

cover neurons (dendrites and cell bodies), the inner surface of pia mater, and every blood vessel in CNS