Brainscape's Knowledge GenomeTM

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


See full index

BIO 242 > Chapter 12: Nerve Tissue > Flashcards

Chapter 12: Nerve Tissue Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

CNS

A

Brain and Spinal Cord

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

PNS includes

A

12 Pairs of Cranial Nerves
31 Pairs Spinal Nerves
Somatic
ANS

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

ENS

A

Enteric NS: NS of the gut

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

Plexus

A

Network/whole bunch of nerves controlling a region

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

In which NS is axon regeneration more easily accomplished?

A

PNS

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

Sensory Neurons purpose?

A

Afferent: Out of periphery into spinal cord or brain

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

Motor Neuron

A

Efferent: Out from CNS to PNS (Effector)

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

Integrative neuron

A

Association neuron: Within CNS
- Small neuron b/w sensory and motor, typically in the spinal cord
- Processing takes place here

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

Two main nerve cells

A

Neurons and neuroglia

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

Difference bw Neurons and Neuroglia

A

Neurons: Electrically excitable (Produce nerve impulse (AP)

Neuroglial (Glue: Cells located around neruons providing structure and protection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

3 Parts of most neurons

A

Cell body
Dendrites
Axon

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

Cell body

A

Location of nucleus

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

Dendrite

A

Small nervous appendages - bring info into cell body from other neurons, receptors etc.

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

Axon

A

Long tail conducting/carring AP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Nissl Bodies

A

Important organelles in cell body - Clusters of rough ER (Critical for repair and growth of damaged nerve)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Axon Hillock

A

Location where axon joins cell body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Initial segment

A

Trigger zone, portion of axon where nerve impulse begins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Axolemma

A

Membrane around axon on outermost portion (structure is a phospholipid)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Axoplasm

A

Cytoplasm of axon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Trophic factos

A

Any chemical hormone etc. that will stimiulate chemical growth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Lipofuscin

A

An example of a trophic factor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Synaptic Vesicle

A

Stores various NT’s before releasing them into the Synaptic cleft

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What factors slow axonal transport

A

Non-myelinated
Smaller diameter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is a slow speed for an axon to transport at?

A

1-5mm per day

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what is a fast speed for axonal trasport

A

200-400mm per day

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What factors speed up axonal transport?

A

Myelation
Larger axon diameter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Multipolar Neuron

A

Multiple dentridtes, one main axon
Typically found in brain and spinal cord

i.e Motor neurons & Interneurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Bipolar Neurons

A

One main dendrite and one axone
(Typically found in special senses ex taste, smell, sight etc.)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Unipolar (Pseudounipolar)

A

Dendrite and axon is fused with the cell body off to the side
(Typically seen in general senses ex, touch, pressure etc.)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What can the maturation of Bipolar neurons result into

A

Unipolar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Purkinjie

A

Larger nerves typically found in heart branch off of main nerves and end up in tissue (very sensitive – can produce coordinated pumping action)

multipolar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Pyrmidal Neurons

A

Mainly found in cortex, labelled by there shape

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Astrocytes

A

Many processes and most abundant neuroglia cell

Maintain environment around neurons and form BBB

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Protoplasmic

A

Short branching processes in gray matter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Fibrous

A

Long unbranched process in white (Myelinated) matter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Astrocytes role

A

Regulate body growth in fetus, aid in learning and memory

Form BBB

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Oligodentrocytes

A

Myelination in CNS axons
Myelinate several axons at a time
Influence repair rate (Slowing it down)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Microglia

A

Phagocytes of CNS
In dendrites
Prune unwanted synapses and routes (Remaining becomes more functional and stronger)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Ependymal cells

A

Cuboidal/columnar neuroglia cells, line ventricles in brain and central canal in spinal cord produce and direct CSF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Schwann (Neurolemmocytes)

A

Single axon myelination in PNS to help with regeneration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Satellite Cells

A

Supply nutrients to neurons in PNS and structure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Which Nervous system has the greatest capacity toregrowth?

A

PNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What is MS

A

Myelin sheath begins to break down causing loss of movement and control

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What myelinates in PNS

A

Schwan cells

45
Q

What myelinates in CNS

A

Oligodendrocytes

46
Q

myelin is composed of

A

Lipd and protein and is multilayered

47
Q
  • Nodes of Ranvier (Neurofibril node) – gaps in myelination
A
  • Only occur in Myelinated neurons where there is NO myelination – extreme concentration of pumps at these locations, allows electricity to jump from NODE to NODE
48
Q

Ganglia/on

A

Collection of Cell Bodies in the PNS

49
Q

Nucleus

A

Collection of cell bodies in CNS

50
Q

Nerve

A

Bundlw od axons in PNS

51
Q

Tract

A

Bundle of axons in CNS

52
Q

Gray Matter

A

Mainly made up of high conc. of cell bodies, dendrites, unmyelinated axons, axon terminals and neuroglia.

53
Q

White matter

A

Primarily made up of myelinated neurons and axons

54
Q

How does an AP for movement get to a muscle

A

Initiated in motor cortex, signal travels down tracts in spinal cord, leaves spinal cord level and then travels to muscle

55
Q

How does a nerve impulse relate to the strength of a movement?

A

Larger number of muscle fibers required for movement; larger number of neurons required for movement

56
Q

Action Potentials

A

Typically starting at intial segment
Travel great distances
Only in one direction
ALWAYS same strength

57
Q

Graded Potentials

A

Electrical impusle travels in both direcitons
Short distance communication
- Can be of different strengths.
- If graded potential is strong enough it becomes action potential.

58
Q

Upper Motor Neuron

A
  • Motor Neurons in CNS that leave the brain and connect to the Lower Motor Neurons
59
Q

Lower Motor Neuron

A
  • Motor Neurons in CNS that leave the brain and connect to the Lower Motor Neurons
60
Q

RMP

A

Resting MEmbrane Potential
(Electrical voltage difference across cell membrane)

61
Q

Ion Channels

A

allow ions to move across membrane down concentration gradient

Allow electrolytes to move back and forth to create current/signal

62
Q

What produces electrical impulses?

A

AP and GP are produced when ion channels open and close to let - / + charged ions flow back and forth like electrical current down their electrochemical gradient.

63
Q

How do Ion channels work?

A
  • Ions move: H to L concentration
  • Negative to Positive areas
  • Positive to Negative areas
  • Channels open and close due to the presence of gates.
    Allows electrolytes to flow back and forth
64
Q

4 Main types of ion channels

A

Leakage
Voltage-Gated
Ligand-Gated
Mechanically Gated

65
Q

Leakage Channels

A

Always open (Small amount of electrolytes to flow through continuously)
- Mainly responsible for establishing RMP

66
Q

Voltage-gated Channels

A

Opens and closes in response to changes in voltage on either side of axon

67
Q

Ligand Gated Channels

A

Implies channel has receptor site and ligand (NT) must attach to that channel which then opens it and allows flow.

68
Q

Mechanically Gated

A

Gate opens in response to mechanical forces: touch, itch, tickle etc.

69
Q

Potential means

A

Difference in electrical charge

70
Q

At resting potential the cell is…

A

More negative inside and more positive outside

71
Q

Typical RMP is

A

-70mV
(Negative indicates inside cell is more negative)

72
Q

3 major factors that create RMP

A

Unequal distribution of ions (Electrolytes)

Inability of anions to leave cell (Negativity is established inside cell)

Electogenic natur of Na+-K+ ATPases (enzyme that runs the sodium potassium pump)

73
Q

Graded Potential Commonalities

A
  • Most in dendrites and cell bodies

MOST common in dendrites

LEAST common in axons

OFTEN dies out, won’t always produce AP

  • Small deviation from RMP
  • Permits variations in amplitude of signal (Signal strgth based on number of gatese open)
  • Local Current (Can move in either direction)
  • Decremental conduction – GP dies out as they move along
74
Q

Generation of Action Potential

A
  • Two main phases:
  • Depolarization – the negative membrane potential becomes less negative, reaches zero, and then becomes positive
  • Inside of cell becomes more positive
  • Repolarization – MP restored to -70mV IMPORTANT diagram
  • Threshold of AP
    -55 mV
75
Q

Result of Sub threshold stimuli

A
  • Causes some depolarization but doesn’t cause AP bc it doesn’t reach the threshold (Therefore no sensitivity to that stimulus
76
Q

Result of supra threshold stimulus

A

Produces several action potentials

77
Q

Describe the four steps of an AP

A

Resting state: Voltage gated channels are closed, axon membrane is at resting potential
- Small build up of negative charges along inside of membrane and positive along outside

Depolarizing Phase: Membrane potential of axon reaches threshold, Na+ voltage gated channels open (Activation channels)
- Na+ ions move into neuron through these channels
- Positive ions buildup along inside of axon membrane causing it to become depolarized

Repolarization begins: Na+ channel inactivation gates close and K+ channels open. Membrane starts to repolarize as K+ Ions leave neurone (Build up of negative charges along inside membrane.

Repolarization continues: K+ outflow continues, as K+ leaves more negative ions build up along inside membrane. K+ outflow eventually restores RMP. Na+ inactivation gates open .

Returns to rest when K+ channesl close

78
Q

Refractory Period

A
  • Time after the FIRST action potential when a second one is NOT POSSIBLE
79
Q
  • Absolute Refractory Period
A
  • Even with STRONG stimuli another AP cannot be produced (Sodium channels unable to open any more)
80
Q
  • Relative Refractory Period
A

no response (AP) to normal Stimuli - AP can be produced if it is STRONG stimulus (voltage gates are open longer)

81
Q

Neurotoxins

A

– “poisons” that effect nervous system (eg. Puffer fish)
- Stopping the voltage gated channels from working (no depolar/repolarization)

82
Q

How do Local Anesthetics work?

A
  • Stopping production of Aps (perception of pain)
  • Block the gates in the axons in that local area
  • Sicknesss can affect effectiveness
83
Q

How does icing work?

A
  • Slowing velocity of action potential
84
Q

How do nerve impulses propagate on a non-myelinated axon

A
  • Continuous (step by step depolarization and repolarization)
85
Q

How do nerve impulses propagate on myelinated axons

A
  • Saltatory (myelinated axons) – leaping AP due to uneven distribution of voltage-gated channels
  • Typically in myelinated axon
  • Fast
  • Energy efficient (less gates involved)
86
Q

Classifications of nerve fibres

A

A - Biggest axon diameter (Fastest)
B
C - Smallest Axon Diameter (Slowest)

87
Q

How does temperature affect AP?

A

Cooler temperature = slower velocity

88
Q

Different types of synaptic signal transmission?

A

Axondendritic (Most common)
Axosomatic (Axon to cell body)
- Somatic neuron
Axoaxonic

89
Q

What is an electrical synapse?

A

AP travels between two plasma membranes through gap junctions
- Tunnels that electrical current can pass through (connexons)
* Faster
* Synchronize group of neurons (or fibers)
* Common in cardiac muscle, viscera, and embryo

90
Q

What does tropic mean?

A

Growth

91
Q

I = Ionotropic Receptors

A

NT binds directly to the channel

92
Q

M=Metabotropic Receptros

A

Second messenger system
- First binding to G protein which causes channel to close
-Slightly slower than I

93
Q

EPSP

A

ExcitatoryPost Synaptic Potential
Type of GRADED POTENTIAL
Gets closer to AP threshold (Depolarizing signal)

94
Q

IPSP

A

Inhibitory Post Synaptic Potential
- Postsynaptic membrane is polarized farther away from the AP threshold therefore less likely for the neuron to generate an AP

95
Q

What are the 3 ways NTs are removed

A
  1. Diffusion
    - NT floats away in synaptic cleft
  2. Enzymatic Degradation
    - Enzyme breaks down NT and it becomes inactive
  3. Uptake by cells
    - Cell that release NT or neightboring cells reuptake the cell to be used later
96
Q

Spatial Summation

A

: Many Presynaptic neurons fire at once summating towards an AP on a single postsynaptic neuron.

-1000 to 10000 synapse at atypical neuron in CNS
Summation of post synaptic potential

97
Q

Temporal Summation

A

One presynaptic neuron continuing to release NTs which add together on the postsynaptic neuron.

98
Q

What is the result of Summation?

A

EPSP, IPSP or AP

99
Q

How many types of NTs are there?

A

100+

100
Q

Modification of NT Effects examples

A

Increase/decrease release of NT (I.e Parkinsons inadequate release of dopamine)

  1. Enhance (agonist) or blocked (antagonist)
    - Some drug or chemical that mimics the effects of the receptor
    - OR Blocks receptor
  2. Stimulated or inhibited the removal of NT
    - Illicit drugs
101
Q

Simplest Neural Circuit

A

One pre and one post synaptic neuron

102
Q

Diverging circuit

A

Begins with one neuron and recruits more and more
(The spine uses this)

103
Q

Converging Circuit

A

Many neurons converge into one
(i.e. Many receptors in nose converge into olfactory nerve)

104
Q

Reverberating circuit

A

Similar to a positive feedback loop (Memory, breathing, HR etc.)

105
Q

Parallell after discharge Circuit

A

Likely used for complex thinking and analysis skills

106
Q

How is a Myelin Sheath Formed?

A

Oligodendrocytes (CNS) or Schwann Cells (PNS) wrap around small section of the axon forming myelin sheath.
The cytoplasm and nucleus are pushed to the outside forming the neurolemma.

107
Q

Saltatory

A

Saltatory (myelinated axons) – leaping AP due to uneven distribution of voltage-gated channels

108
Q

3 main functions of NS to maintain homeostasis

A

Sensory
Motor
Integrative

109
Q

CNS vs PNS

A

CNS is brain and Spinal Cord

PNS is Motor and sensory division
of the motor: their is the somatic and autonomic division
Of ANS: Sympathetic and Parasymathetic

BIO 242 (17 decks)

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