Chapter 13 - Neural Tissue Flashcards

0
Q

What is the transmission of signals in the nervous system?

A
  • Body parts to the central nervous system

- Central nervous system to the body parts

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

- Accomplished by the transmission of signals

A

Nervous system

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

What kind of signaling does the nervous system do?

A

Electrochemical signaling

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

- Uses chemicals in the blood stream called hormones

A

Endocrine system

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

Nervous system is made up of many organs, each composed of several tissues

A
  • Connective tissues
  • Blood vessels
  • Neurons
  • Neuroglia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Two groups and divisions of the nervous system

A
  1. Central NS

2. Peripheral NS

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

Brain and spinal cord

A

CNS

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

Cranial and spinal nerves and ganglia

A

PNS

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

Five characteristics of the CNS

A
  • Brain and spinal cord
  • Covered by meninges
  • Starts as a hollow tube
  • Bathed in cerebrospinal fluid
  • Integration center
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Three components to the PNS

A
  • Consists of CRANIAL and SPINAL NERVES and GANGLIA that contain both SENSORY and MOTOR FIBERS
  • Connects CNS to muscles, glands and all sensory receptors
  • Brings info to and from the CNS
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Two divisions of the PNS

A

Afferent division = sensory

Efferent division = motor

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

Two divisions of the efferent division

A

Somatic division = conscious

Autonomic division = unconscious

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

General functions and processes of the CNS and PNS

A
  1. Receptors = direct stimuli
  2. Sensory = afferent PNS
  3. Integrative = CNS
  4. Motor = efferent PNS
  5. Effector = muscle/gland
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q
  • Structural and functional units
  • Excitable
  • Amitotic
A

Neurons

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

- Act like connective tissue

A

Neuroglial cells

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

Three major structures of neurons

A
  1. Soma
  2. Dendrites
  3. Axon
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Cell body is mononucleate

A

Soma

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

The parts of the Soma

A

Nissl bodies = ribosomes clusters; give gray color
Axon hillock = connects soma to axon
Perikaryon = region around the nucleus
Neurofibrils = cytoskeleton that extend into dendrites/axons; gives shape

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

Four characteristics of dendrites

A
  1. Respond to neurotransmitters
  2. Short, branched, UNMYELINATED
  3. Specialized for contact with other nuerons
  4. Conducts impulses towards the cell body
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Four characteristics of axons

A
  1. Only one cell
  2. Conducts nerve impulses away from soma
  3. Can give off collaterals
  4. Many wrapped in myelin sheath; glial cells wrapped around the axon
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Where does the axon end?

A

Synaptic terminal

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

What does the axon produce?

A

Neurotransmitters

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

The axons may contact what three things?

A
  1. Another neuron
  2. Muscle fibers
  3. Glands
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q
  • also known as axoplasmic flow

- movement of cellular materials (not signals) through the axon

A

Axonal transport

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q
  • Away from soma; neurotransmitters, organelles, nutrients
A

Anterograde

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

Toward soma; degraded materials to be recycled and extracellular substances

A

Retrograde

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

The cytoplasm of an axon

A

Axoplasma

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

What does the axoplasma consist of?

A
  • Few Organelles

- Cytoskeletal proteins

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

What do cytoskeletal proteins do?

A
  • Form cytoskeleton
  • Maintain shape
  • Generate axonal transport
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Plasma membrane of axons

A

Axolemma

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

What does the axolemma consist of?

A

Collaterals: side branches
Telodendria: terminal extensions
Synaptic terminal: contains synaptic vesicles; where neruon contacts postsynaptic cell

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

Sructural classification of neurons is based on what?

A

The number and morphology of dendrites

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

The structural classification of neurons

A
  • Anaxonic
  • Bipolar
  • Unipolar
  • Multipolar
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q
  • Small neurons

- Axons can not be distinguished from dendrites

A

Anaxonic

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

Where are anaxonic structures of neurons

A

CNS, especially interneurons that coordinate special senses

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

Three characteristics of bipolar structures of neurons

A
  • Several small dendrites converge into one
  • Dendrite and axon separated by soma
  • Unmyelinated
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Where is the bipolar structure of a neuron?

A

Sensory neurons of special sensory organs

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

Another name for unipolar structures of neurons

A

Pseudo-unipolar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q
  • Several small dendrites converge onto one large one
  • Dendrite and axon continuous
  • Usually myelinated
A

Unipolar

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

Where are the unipolar structure neurons located?

A

Majority of sensory neurons in PNS

40
Q
  • Many dendrites extend from soma
  • Long axon
  • Myelinated
A

Multipolar structure of neurons

41
Q

Where are multipolar structures of neurons?

A
  • Majority of motor neurons in PNS

- Spinal interneurons in CNS

42
Q

Characteristics of afferent neurons

A
  • Have sensory functions
  • Cell body usually are outside of CNS
  • Have receptor ends on dendrites or are associated with receptor cells in sense organs
  • Carry impulses from peripheral body parts to brain or spinal cord
43
Q

Three receptors in afferent neurons with their meanings

A
  1. Exteroceptors = touch, temperature, pressure, light, chemicals
  2. Proprioceptors = monitor muscle and skeleton position
  3. Interoceptors = monitor internal systems (digestion, urinary, ect)
44
Q
  • Neurons only in CNS
  • Most abundant
  • Link two or more neurons
A

Interneurons

45
Q

Two classifications of interneurons

A
  1. Excitatory

2. Inhibitory

46
Q
  • Have motor function
  • Cell body usually inside of CNS
  • Carry impulses from the brain or spinal cord to peripheral body parts
A

Efferent Neurons

47
Q

Two different kinds of efferent neurons

A
  • Somatic

- Autonomic

48
Q

Controls skeletal muscle

A

Somatic (efferent neurons)

49
Q

Smooth muscles and glands

A

Autonomic/visceral (efferent neurons)

50
Q

Six neuroglia cells

A
  1. Satellite (PNS)
  2. Schwann cells (PNS)
  3. Astrocytes (CNS)
  4. Oligodendrocytes (CNS)
  5. Ependymal cells (CNS)
  6. Microglia (CNS)
51
Q
  • Largest and most common neuroglial cell

- Star shaped

A

Astrocytes

52
Q

Functions of astrocytes

A
  • Structure and repair
  • Metabolism
  • Regulate ions and nutrition
  • Guide neurons to targets
  • Form blood brain barrier
53
Q

Like astrocytes but alot smaller

A

Oligodendrocytes

54
Q

Functions of oligodendrocytes

A
  1. Form myelin in CNS

2. Sequester debris

55
Q
  • Smallest and least common neuroglia cell

- Derived from myeloid cells

A

Microglia

56
Q

Functions of microglia

A
  • Help support neurons
  • Phagocytosis
  • Increase in number during injury or disease
57
Q
  • Columnar/cuboidal
  • Microvilli on luminal surface
  • Joined by gap junctions
A

Ependymal

58
Q

Functions of ependymal

A
  • Help produce cerebrospinal fluid
  • Form porous layer
  • Monitor CSF composition
59
Q
  • Associated with soma
  • Assist with exchange of nutrients
  • Isolates neuron from extraneous stimuli
A

Satellite

60
Q
  • Produce myelin in PNS

- Encloses axons of longer peripheral nerves

A

Schwann cells

61
Q

Functions of Schwann Cells

A
  • Support neurons
  • Prevent contact
  • Myelinate large PNS axons
62
Q
  • Appear gray
  • Many axons associate with single Schwann cells (Rarely are PNS axons without any coverings)
  • CNS; no glial cells
A

Unmyelinated

63
Q
  • Appear white
  • CNS; Ogliodendrocytes myelinates parts of several axons
  • PNS; Schwann cells myelinates part of one axon
A

Myelinated

64
Q

Plasma membrane of Schwann cell wrapped around axon

A

Myelin

65
Q

Part of Schwann cell that contains cytoplasm

A

Neurilemma

66
Q

Gaps in myelin sheath

A

Nodes of Ranvier

67
Q

Explain the myelination process

A

Starts at week 14 and completed by ages 2-3 years

68
Q

Myelin function

A
  • Isolates axons

- Increase rate of action potential

69
Q

Regeneration of nerve fibers in PNS

A
  • Can regenerate a fraction of the axons

- Schwann cells participate in process

70
Q

Can regenerate a fraction in fibers in the PNS

A

Wallerian Degeneration

71
Q

Refer to study sheet to explain the regeneration of nerve fibers

A

:)

72
Q

Explain neuron repairs in the CNS

A
  • More limited
  • Degeneration occurs after injury
  • Oligodendrocytes do not proliferate
  • Proximal end sprouts but has no tube to follow
  • Astrocytes produce scar tissue and chemicals blocking regrowth
73
Q

Ability to respond to stimuli

A

Irritability

74
Q

Ability to transmit an impulse

A

Excitability

75
Q

An electrical impulse changing the permeability of a membrane

A

Action potential

76
Q

AP moving down an axon

A

Nerve impulse

77
Q

Impulse travels fast when

A
  1. Axon is myelinated

2. Has a larger diameter

78
Q

Functions as control and transport point

A

Synapse

79
Q

The site of communication in a synapse is between what?

A
  • Sensory structure and neuron
  • Neuron and effector
  • Two neurons
  • Any two cells with gap junctions
80
Q

Two types of synapses

A
  1. Electrical

2. Chemical

81
Q

Gap junctions cause the exchange of charged ions between two cells

A

Electrical

82
Q

Example electrical synapses

A

Intercalated disks in cardiac muscle

83
Q

Chemicals are released by one cell and travel to another

A

Chemical synapse

84
Q

Example of chemical synapse

A
  • Neuro-muscular junction

- Nueron-neuron contact

85
Q

House neurotransmitters in the chemical synapse

A

Synaptic vesicles

86
Q

Process of chemical synapse

A
  1. Synaptic vesicles house neurotransmitters
  2. Only exist in the presynaptic cell
  3. Release neurotransmitter into synaptic cleft
  4. Receptor on post- synaptic membrane register the neurotransmitter
  5. Proliferates AP form one cell to the next
  6. Communication in one direction only (only axons have synaptic vesicles)
87
Q

Steps at chemical synapse

A
  1. AP reaches synaptic knob of presynaptic neuron
  2. Neurotransmitter released
  3. Neurotransmitters crosses cleft and binds to receptors in post-synaptic membrane
  4. Get change in permeability (can be excitatory or inhibitory)
  5. Neurotransmitter is then removed from synaptic cleft
  6. Permeability returns to original state
88
Q
  • Receive impulses from afferent fibers (input)
  • Impulses carried away on efferent fibers (output)
  • Afferent fibers can branch many times as they enter a pool
A

Neuronal Poolw

89
Q

Many types of neuronal pools

A
  1. Convergence
  2. Divergence
  3. Serial processing
  4. Parallel processing
  5. Reverberation
90
Q

One neuron to another in series

A

Serial processing

91
Q
  • When impulse leaves a pool, it may spread into several output fibers
  • Allows impulse to be amplified
A

Divergence

92
Q
  • Single nerve in pool may receive impulses from two or more incoming fibers
  • If lead to same nerve; they are said to converge
  • Allows summation of impulses from different sources
A

Convergence

93
Q

Processing information from several neurons at once

A

Parallel processing

94
Q

Positive feedback continues activity of circuit

A

Reverberation

95
Q

Steps to facilitation

A
  1. One neuron may receive either excitatory and inhibitory stimuli from multiple neurons
  2. The net effect of all this input results in a net charge. If this charge is positive enough, it will result in an AP.
  3. The point where an AP can be produced is known as threshold.
  4. If a neuron is excited, but still below threshold. (No impulse, but nerve is more excitable to next impulse; said to be facilitated)
  5. This whole system allows for the multiple sources to mange the nervous sytem
96
Q

CNS structure with meanings

A
Nuclei = collection of neuron cell bodies
Center = collection of neuron cell bodies working together
Tracts = bundles of axons
97
Q

PNS structure with meanings

A
Ganglia = collection of neuron cell bodies 
Nerves = bundles of axons