Pns

Front 1

List three characteristics of the nucleus (nut) of the neurons in the PNS.

Back 1

1. Large Round/Ovoid
2. Euchromatic
3. Prominent nucleolus LL fried egg

Front 2

What is a nissl body?

Back 2

basophillic clumps of RER and polysomes

Front 3

What is a perikaryon? List 5 characteristics

Back 3

The cytoplasm of the cell body.
Nissl body
Neurofilaments are microtubules (GTP)
Large golgi
Many mito
No secretory granuals, but has secretory vessicles

Front 4

The two types of cell processes are dendrites and axons. Compare and contrast

Back 4

Dendrites
1. Branches(lots) that taper
2. Variable diameter
3. Fewer neurofilaments than axons (mainly microtubules)
4. Spines (allow them to interact w/ other neurons)
5. Spines carry graded potentials (EPSP or IPSP)
Axons
1. One per cell
2. LONG in PNS
3. Axolemma and axoplasm
4. Microtubules
5. Occasionally branch, called collaterals
6. May or may not be myelinated

Front 5

Describe the initial segment of an axon.

Back 5

It is never myelinated, and it contains the trigger zone (the place where the action potential is generated)

Front 6

Describe slow and FAST axonal transport.

Back 6

Slow: unidirectional, always from the cell body
FAST: ATP dependent, bidirectional, involves microtubules, kinesins and dyneins.

Front 7

Describe Kinesins and dyneins

Back 7

Look this up!!

Front 8

In peripheral nerves, what are the layers from the inside --> out?

Back 8

Axon
Endoneurium
Fascicle
Perineurium (dense-irregular)
Epineurium (dense-irregular, fibroblasts/fibrocytes)

Front 9

What layer is the
"blood-nerve barrier?"

Back 9

The fascicle. It also has tight junctions which are unusual for cx tissue.

Front 10

What type of cells are Schwann Cells? What do they contain? What surrounds them? What do they surround?
Capeable of mitosis?
Capeable of generating an action potential?

Back 10

Glial cells, in fact, the only ones in the PNS.
GFAP. External lamina (basal) Axons
Yes
No

Front 11

What are satallite cells and where are they found?

Back 11

Satallite cells are simply Schwann cells found wrapped around cell bodies.

Front 12

In Schwann sheaths, axons are typically _______ in diameter and conduction velocity is ________.

Back 12

Small
Slow

Front 13

In a myelinated axon, diameter is ______ and conduction velocity is ______.

Back 13

Large
Fast

Front 14

Protein Zero (P0)

Back 14

E surface
Intraperiod line

Front 15

Myelin basic protein

Back 15

P surface
Major dense line

Front 16

What types of nerves do not have nodes of Ranvier?

Back 16

Unmyelinated

Front 17

If you had a cross-section of one myelinated nerve, how many SC could you be looking at?

Back 17

One, it simply wraps itself over and over again.
Myelin circumnavigates around axons laying down (DLDL)unit membranes, squeezing out cytoplasm.

Front 18

Are there gap junctions in the PNS?

Back 18

No, but they are in the CNS, allow for direct communication.

Front 19

What type of communication takes place between Neurons in the PNS?

Back 19

Indirect communication btwn cells.
Ex: Axodendritic (btwn an axon and a dendrite)

Front 20

What are the two neuromuscular synapses?

Back 20

1. Smooth and cardiac muscle = en passant (buldges in axon)
2. Skeletal muscle = myoneural jx

Front 21

How do synaptic vesicles attach to active zone of presynaptic membranes?

Back 21

Synaptophysis

Front 22

What is the fx of synapsin?

Back 22

Attaches synaptic vesicles to microfilaments

Front 23

Describe the chemical synapse btwn two neurons.

Back 23

It occurs via paracrine secretion, very fast diffusion.
Has many mito and synaptic vessels containing neurotransmitters. Synaptic vessels attach to microfilaments via synapsin and to the active zone via synaptophysin. Bouton membrane has voltage gated Ca channels, synaptic cleft, postsynaptic component.

Front 24

Explain nodes of Ranvier

Back 24

Pt on the axon devoid of myelin

Front 25

Explain Schmidt-Lantermann

Back 25

slanting segments where local separations occur btwn nerve fibers (funnel fasion)

Front 26

Explain the Neurokeratin network.

Back 26

NO Keratin IF
Spongy framework remaining when myelin has been removed.

Front 27

Describe the three types of peripheral nerve fibers

Back 27

A Very Fast, large diameter, very myelinated, Accute pain (GSA), innervate skeletal muscle.
B Slow, small diameter, myelinated, preganglionic autonomics (GVE)
C Slowest, smallest, unmyelinated, post-ganglionic autonomics (GVE

Front 28

Explain nodes of Ranvier

Back 28

Pt on the axon devoid of myelin

Front 29

Explain Schmidt-Lantermann

Back 29

slanting segments where local separations occur btwn nerve fibers (funnel fasion)

Front 30

Explain the Neurokeratin network.

Back 30

NO Keratin IF
Spongy framework remaining when myelin has been removed.

Front 31

Describe the three types of peripheral nerve fibers

Back 31

A Very Fast, large diameter, very myelinated, Accute pain (GSA), innervate skeletal muscle.
B Slow, small diameter, myelinated, preganglionic autonomics (GVE)
C Slowest, smallest, unmyelinated, post-ganglionic autonomics (GVE

Front 32

Interoreceptors

Back 32

Sensory endings in blood vessels and viscera.

Front 33

Proprioreceptors

Back 33

In muscles, tendons, joints and inner ear.

Front 34

Nociceptors

Back 34

Respond to stimuli that cause pain (tissue damage).

Front 35

Give one example of nonencapsulated mechanoreceptors.

Back 35

Free nerve endings - simplest mechanoreceptors, unmyelinated, lack SC, not covered by cx tissue capsule.

Front 36

Give one example of encapsulated mechanoreceptors.

Back 36

Pacinian corpuscles - hands and breasts, respond to pressure, touch and vibration.

Front 37

GSA
GVA
GSE
GVE

Back 37

from skin, sk mus & joints
from viscera including bld vs
to sk muscle from myotomes
to smooth muscle, cardiac muscle, and glands

Front 38

When is Acetylcholine used?

Back 38

GSE and pre-ganglionic GVE

Front 39

When is norepinephrine used?

Back 39

Post-ganglionic GVE

Front 40

Conscious perception vs Sensations
Which is the same in everyone, and which is different from person to person?

Back 40

Sensations
Conscious Perception

Front 41

Is the spinal nerve proper afferent, efferent or mixed?

Back 41

Mixed

Front 42

The spinal nerves attach to the spinal cord via roots. Describe them:

Back 42

Dorsal root: afferent/sensory "to" sp cord
Ventral root:
efferent motor "from" sp cord

Front 43

What are ganglia?

Back 43

Aggregations of cell bodies outside the CNS.

Front 44

What is the neurotransmitter of sensory ganglia?

Back 44

Glutamate. The sensory ganglia is known as the Dorsal Root Ganglia, they are unipolar, have cell bodies but not synapses.

Front 45

Where are the cell bodies of the autonomic ganglia? What type are they?

Back 45

In the tubular organ of the gut.
Multipolar cell bodies

Front 46

Define neuron

Back 46

A nerve cell

Front 47

Define nerve fiber

Back 47

an axon and its various sheaths
(In PNS, always have SC and often have myelin sheath)

Front 48

Define nerve

Back 48

Collection of nerve fibers and their specialized CT sheaths (epineurium, perineurium, endoneurium)