Nervous System I: Neurohistology Flashcards
1
Q
what are the two components of the human nervous system?
A
- central nervous system (CNS)
- peripheral nervous system (PNS)
2
Q
CNS components
A
- brain
- spinal cord
3
Q
PNS components
A
- somatic (voluntary division)
- autonomic (involuntary division)
4
Q
define neurons
A
- conducting elements (cells)
- makes up a part of the nervous system
5
Q
define neuroglia
A
- accessory elements
- known as being supporting cells of the nervous system
6
Q
define meninges
A
-coverings within the nervous system
7
Q
neuron function
A
-responsible for receiving and transmitting information
8
Q
classificational functions of neurons types
A
- sensory (afferent)
- motor (efferent)
- associative (interneuron)
9
Q
neuron sensory function
A
-transmits impulse from periphery sensory recover to spinal cord or brain
10
Q
neuron motor function
A
-transmits information from CNS to peripheral effectors
11
Q
neuron motor function examples
A
- skeletal muscle
- smooth muscle
- cardiac muscle
- glands
12
Q
neuron associative function
A
- located between sensory and motor neurons in CNS
- modifies responses of hormones
- relays information to other neurons
13
Q
structural functions of neurons types
A
- multipolar
- bipolar
- unipolar
14
Q
neuron multipolar structure
A
- has more than two processes attached to cell body
- most common type of neuron formed throughout CNS
15
Q
neuron bipolar structure
A
- has two processes attached to cell body
- found in retina of eye and inner ear
16
Q
neuron unipolar structure
A
- has only one process attached to cell body
- found in ganglia which are chapters of neurons adjacent to spinal cord
17
Q
structure of typical neuron
A
- cell body
- processes (fibers) of a neuron
18
Q
neuron cell body components
A
- most of the organelles typically found in cells (nucleus, mitochondria, golgi complex, etc)
- nissl bodies
- neurofibrils
19
Q
neuron body: nissl bodies
A
- chomato philic bodies
- clusters of ribosomes of RER that module protein (neurotransmitters made of protein)
20
Q
neuron body: neurofibrils
A
-cytoskeleton of neuron transport and maintain shape o neuron
21
Q
neuron processes(fibers) of a neuron components
A
- dendrites
- axon (nerve fibers)
22
Q
neuron fibers of a neuron: dendrites
A
- more than one per neuron
- receives impulse and transmits to cell body
23
Q
neuron fibers of a neuron: axon
A
- only one per neuron
- transmits info away from the cell bud to another neuron or muscle
24
Q
what are axons?
A
-nerve fibers
25
special characteristics of nerve fibers components
- myelin sheath
- neurolemma
- nodes of ranvier
- synaptic vesicles
26
special characteristics of nerve fibers: myelin sheath producer and location
produced by:
- oligodendrocytes in CNS
- schwann cells in PNS
27
special characteristics of nerve fibers: myelin sheath composition
-composed of primarily lipid(fat)
28
special characteristics of nerve fibers: myelin sheath function
-to increase transmission speed an electrical impulse
29
special characteristics of nerve fibers: neurolemma
-cell membrane of oligodendrocyte or schwann cell
30
special characteristics of nerve fibers: nodes of ranvier
- area of axon that's not covered by myelin
| - assists with rapid transmission of impulse
31
special characteristics of nerve fibers: synaptic vesicles
-structures that store neurotransmitters that are released at a synapse
32
allowers of communication in between neurons
- synapses
| - conduction of nerve impulses
33
allower of communication in between neurons: synapse
- space between axon of a presynaptic neuron
| - dendrite of postsynaptic neuron
34
allower of communication in between neurons: synapse components
- presynaptic neuron
- synaptic cleft
- postsynaptic neuron
35
allower of communication in between neurons: synapse: presynaptic neuron
-transmits impulse
36
allower of communication in between neurons: synapse: synaptic cleft
-space between the presynaptic axon and the dendrite of the postsynaptic dendrite
37
allower of communication in between neurons: synapse: postsynaptic neuron
-receives info
38
allower of communication in between neurons: conduction of nerve impulse characteristics
- resting membrane
- depolarization
- "wave of negativity"
- repolarization
39
allower of communication in between neurons: conduction of nerve impulse: resting membrane
- polarized
- positive charge outside cell membrane
- Na+ ions outside cell membrane
40
allower of communication in between neurons: conduction of nerve impulse: depolarization
- caused by influx of Na+ ions into cell
| - negative charge on outside cell membrane
41
allower of communication in between neurons: conduction of nerve impulse: wave of negativity
-a wave of negativity travels along cell membrane
42
allower of communication in between neurons: conduction of nerve impulse: repolarization
-caused by influx of K+ ions to outside of cell
43
allower of communication in between neurons: conduction of nerve impulse: repolarization types of conduction
- continuous conduction
| - stationary conduction
44
allower of communication in between neurons: conduction of nerve impulse: continuous conduction
-along myelinated axons; a continuous wave
45
allower of communication in between neurons: conduction of nerve impulse: stationary conduction
- conduction "jumps" along myelinated axon
| - conducts only at nodes of ranvier (but more rapid)
46
types of nerve fibers
- A fibers
- B fibers
- C fibers
47
A fibers
- most heavily myelinated
- fast conduction
- sharp, stabbing pain
48
B fibers
- intermediate amount of myelin
- moderate speed
- moderate pain
49
C fibers
- least myelin (sometimes no myelin)
- slow speed
- dull, aching pain
50
define nuclei
-cluster of neurons in CNS
51
define ganglia
-cluster of neurons in PNS
52
define nerve
-bundles of axons in the PNS
53
define tract
-bundles of axons in the CNS
54
examples of neurotransmitters
- excitatory neurotransmitters
| - inhibitory neurotransmitters
55
excitatory neurotransmitters components
- acetylcholine (Ach)
- norepinephrine (NE)
- serotonin
- dopamine
56
excitatory neurotransmitters: acetylcholine
-involved in muscle contraction and autonomics
57
excitatory neurotransmitters: norepinephrine
-involved in muscle contraction and autonomics
58
excitatory neurotransmitters: serotonin
- plays a role in constriction of smooth muscle
- regulates cyclic body processes
- contributes to mood(feelings of wellbeing and happiness)
59
excitatory neurotransmitters: dopamine
- helps control the brain's reward and pleasure centers
| - helps regulate movement and emotional responses
60
inhibitory neurotransmitters components
- gamma aminobutyric acid (GABA)
- enkephalin
- endorphins
- dopamine
61
inhibitory neurotransmitters: gamma aminobutyric acid
-responsible for regulation muscle tone; inhibitory
62
inhibitory neurotransmitters: enkephalin
- regulates pain perception on the body
| - binds to opiate receptors in the body
63
inhibitory neurotransmitters: endorphins
- group of hormones similar to enkephalins
- activates body's opiate receptors
- exerts an analgesic effect
64
inhibitory neurotransmitters: dopamine
- helps control the brain's reward and pleasure centers
| - helps regulate movement and emotional responses
65
what nervous system are acetylcholine and norepinephrine a part of?
-autonomic nervous system
66
excitatory neurotransmitter function
-causes depolarization of the postsynaptic neuron
67
inhibitory neurotransmitter function
-hyperpolarize the postsynaptic neuron preventing the transmission of the nerve impulse across the synapse
68
what is neuroglia also known as?
-"neural glue"
69
what system is the neuroglia a part of?
-central nervous system
70
neuroglia components
- oligodendrocyte
- microglia
- astrocyte
- ependymal cells
71
neuroglia oligodendrocyte
-cells that produces myelin covering (sheath) around axons in CNS
72
neuroglia microglia
-phagocytic cell that engulfs dead tissue
73
neuroglia astrocyte
- assists in the nourishment of neurons in CNS
| - formation of the Blood-Brain Barrier
74
astrocyte blood brain barrier composition
- endothelium (lining of capillaries)
- basement membrane
- foot process of astrocytes
75
astrocyte blood brain barrier function
- regulates permeability of capillaries to control what enters brain
- prevents large molecules from entering brain
- keeps toxic substances from entering brain cells
76
neuroglia ependymal cells
-line the ventricles of the brain
77
define ventricles
-spaces within the brain
78
types of cells in peripheral nervous system
- schwann cell
| - satellite cell
79
what is another name for schwann cells?
-neurolemmocytes
80
schwall cell
-produces myelin sheath around axon in PNS
81
satellite cell
-regulate nourishment to neuron bodies in the PNS
