Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

CTB > Nerves > Flashcards

Nerves Flashcards

1
Q

Nervous tissue composed of:

A

mostly cells

neurons

glia (supporting cells - glue)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Nucleus

A

group of neuron cell bodies inside the CNS

found in GRAY MATTER of CNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Ganglion

A

group of neuron cell bodies outside the PNS

Two kinds:

  • sensory
  • autonomic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Tract

A

group of CNS axons projecting from one place to another

form WHITE MATTER of CNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Nerve

A

group of fibers in the PNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Afferent

A

towards a source

sensory

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Efferent

A

away from a source

motor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Two areas of the spinal cord:

A

1) Gray Matter - cell bodies - butterfly

2) white

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Nissl Stain

A

stains the RER of neurons

axons dont stain (no protein production)

usually more staining at the ventral horn

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Typical neuron structure (in CNS)

A
  • multipolar
  • cell body with array of organelles
  • multiple tapered dendrites
  • single axon of uniform diameter that has collaterals that branch at right angles to form synapses at the presynaptic terminals
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Axon hillock

A

where axon begins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Initial segment of axon

A

site where action potentials are generated

voltage gated ion channels here

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Nissl substance (RER)

A

synthesizes NT or its precursors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Neuron cell body

A
  • nissl substance
  • lots of golgi
  • microtubules, microfilaments, neurofilaments
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Spines

A
  • increase surface area on dendrites
  • flexible and active
  • contain actin in the neck, no microtubules
  • lose spines as we age
  • neurotransmitter vesicles can fuse with them
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Axons

A
  • no RER (Nissl)
  • use mainly chemical NT
  • Na/K pumps located along entire length
17
Q

Anterograde axonal transport:

A
  • transport NT from cell body to terminal(400 mm/day)

- Kinesin ATPase

18
Q

Retrograde axonal transport:

A
  • recycle substances
  • destroy garbage
  • 200 mm/day
  • Axon terminals can take up toxins/viruses and transport them to the cell body
19
Q

Glial cells in CNS

A
  • in white matter
  • oligodendrocytes: make myelin
  • microglia: macrophage (smallest)
  • fibrous astrocytes: CT, sometimes act like neurons

NOTE: see the same glial cells in gray matter but protoplasmic astrocytes instead

20
Q

Glial cells in PNS

A
  • satellite cells: microenvironment, insulate, allow metabolic exchange
  • Schwann: make myelin
21
Q

Oligodendrocytes versus Schwann

A

O: myelinate up to 50 segments of 50 different axons

S: myelinate only a single segment of ONE axon

22
Q

Demyelination diseases:

A

1) multiple sclerosis: CNS myelin

2) Guillain-Barre: PNS myelin

23
Q

What is myelin

A

membranes of the myelin glial cells wrape around and squeeze out cytoplasm

24
Q

How do axons increase conduction velocity?

A

-increase axon diameter: more current flows through larger tube because decreased resistance

  • insulation so passive current flows further down the axon
    • thicker sheath = faster conduction
25
Q

Nodes of Ranvier

A
  • voltage gated ion channels of myelinated axons only here
  • Na/K pumps only here (myelinated uses less energy)
  • Action potentials jump from node to node
26
Q

Saltatory conduction

A

-Action potentials jump from node to node

27
Q

Regeneration

A
  • axon degenerates distal to the cut (anterograde/Wallerian degeneration)
  • cell body undergoes retrograde chromatolysis
  • PNS can regenerate
  • CNS cannot because no macrophages (microglia are ineffective), instead astrocytes form glial scar and oligodendrocytes undergo apoptosis
28
Q

PNS regeneration:

A
  • myelin and axonal debris cleared quickly by macrophages
  • schwann cells provide a tube for axon sprout growth
  • slow (1-4 mm/day)
29
Q

Inhibitory molecules on myelin suppress CNS axon regeneration:

A
  • nogo
  • myelin associated glycoprotein (MAG)
  • oligodendrocyte-myelin glycoprotein (OMgp)
30
Q

Largest neurons in the spinal cord gray matter

A

ventral horn, motor neurons

31
Q

Retrograde transport diseases

A
  • polio

- tetanus

32
Q

Both retrograde and anterograde transport diseases

A
  • herpes

- rabies

33
Q

Intermediate Zone:

A

-site of termination of the dorsal axons in the spinal cord

34
Q

Why myelin conducts faster

A
  • insulation
  • decreased capacitance (charges dont try to meet outside charges)
  • larger diameter
  • saltatory conduction
35
Q

Unmyelinated action potentials:

A

graded, slower

36
Q

Na/K pump in action potential:

A

-makes the concentration gradient that powers the action potential

CTB (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions