Ch 12 PPT Notes Flashcards
(96 cards)
1
Q
Functions of Nervous System
A
Coordinates and controls body function.
Receives sensory input.
Makes decisions.
Orders body responses
2
Q
Organs of Nervous System
A
Brain
Spinal cord
Nerves
3
Q
alges/o
A
sense of pain
4
Q
astr/o
A
star
5
Q
cephal/o
A
head
6
Q
cerebell/o
A
cerebellum
7
Q
cerebr/o
A
cerebrum
8
Q
clon/o
A
rapid contracting and relaxing
9
Q
dur/o
A
dura mater
10
Q
encephal/o
A
brain
11
Q
esthes/o
A
sensation; feeling
12
Q
gli/o
A
glue
13
Q
medull/o
A
medulla
14
Q
mening/o; meningi/o
A
meninges
15
Q
myel/o
A
spinal cord
16
Q
neur/o
A
nerve
17
Q
poli/o
A
gray matter
18
Q
pont/o
A
pons
19
Q
radicul/o
A
nerve root
20
Q
thalam/o
A
thalamus
21
Q
thec/o
A
sheath (meninges)
22
Q
ventricul/o
A
ventricle
23
Q
–paresis
A
weakness
24
Q
–phasia
A
speech
25
–plegia
paralysis
26
–taxia
muscle coordination
27
–trophic
pertaining to development
28
Nervous system is divided into:
Central nervous system (CNS)
| Peripheral nervous system (PNS)
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Central nervous system consists of:
Brain
| Spinal cord
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Peripheral nervous system consists of:
Cranial nerves
| Spinal nerves
31
Nervous system composed of two types of cells
Neurons
| Neuroglial cells
32
Neurons
Individual nerve cells; Capable of conducting electrical impulses
33
Neurons have three basic parts:
Dendrites
Nerve cell body
Axon
34
Dendrites
Highly branched projections that receive impulses
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Nerve cell body
Contains nucleus & organelles
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Axon
Conducts electrical impulse to destination
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Synapse
"Gap"
| Point where axon of one neuron meets dendrite of second neuron
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Synaptic cleft
Gap between two neurons in a synapse.
| Electrical impulse cannot cross.
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Neurotransmitter
Chemical released by axon.
| Crosses gap to stimulate dendrite of second neuron.
40
Neuroglial cells
Variety of cells found in nervous tissue.
Each has different support function for neurons.
Some produce myelin.
Cells do not conduct electrical impulses.
41
Central Nervous System
Combination of the brain and spinal cord
42
Central Nervous System Function
Receives impulses from all over body.
Processes this information.
Responds with action.
43
What are tracts?
Bundles of nerve fibers interconnecting different parts of CNS.
44
Central Nervous System
Consists of both gray and white matter
45
Gray matter
Comprised of unsheathed or uncovered cell bodies and dendrites
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White matter
Myelinated nerve fibers
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Brain
One of the largest organs in body.
Coordinates most body activities.
Center for thoughts, memory, judgement & emotion.
48
Cerebral Cortex
Outer layer of cerebrum.
| Composed of folds of gray matter.
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Gyri
Elevated portions of the cerebrum or convolutions.
50
Sulci
Fissures or valleys between gyri
51
Lobes of Cerebrum
Subdivided into left & right halves called cerebral hemispheres.
52
Each cerebral hemisphere has four lobes:
Frontal lobe
Parietal lobe
Occipital lobe
Temporal lobe
53
Thalamus
Within diencephalon.
Controls perception of pain.
Center for relaying impulses from eyes, ears & skin to cerebrum.
54
Hypothalamus
Within diencephalon.
Controls body temperature, appetite, sleep, sexual desire & emotions.
Controls autonomic nervous system, cardiovascular system, gastrointestinal system & release of hormones from pituitary gland.
55
Cerebellum
Second largest portion of brain.
Located beneath posterior part of cerebrum.
Aids in coordinating involuntary body movement & maintaining balance & equilibrium.
Refines muscular movements initiated in cerebrum.
56
Brain Stem has (3) components:
Midbrain
Pons
Medulla oblongata
57
Midbrain
Brain stem component:
| Acts as pathway for impulses between brain and spinal cord
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Pons
Brain stem component:
Means bridge.
Connects cerebellum to rest of brain.
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Medulla oblongata
Brain stem component:
Most inferior portion of brain.
Connects brain to spinal cord.
60
Brain Ventricles
Cavities containing cerebrospinal fluid (CSF)
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Cerebrospinal fluid (CSF)
Watery, clear fluid.
| Provides shock protection for CNS.
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Brain Ventricle Locations:
One in each cerebral hemisphere.
One in thalamus.
One in front of cerebellum.
63
Spinal Cord
Extends from medulla oblongata to second lumbar vertebra
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Spinal cord within vertebral column
33 vertebrae of back bone:
Cervical, thoracic, lumbar & sacral.
Line up to form continuous canal.
Called spinal cavity or vertebral canal.
65
Spinal Cord
Protected by cerebrospinal fluid that flows through central canal down through spinal cord.
66
Outer portion of spinal cord is myelinated white matter
Ascending tracts carry sensory information up to brain.
| Descending tracts carry motor commands down from brain to peripheral nerve
67
Meninges
Encases entire CNS.
Protective membrane sac.
(3) layers: dura mater; arachnoid layer; pia mater
68
Dura mater
"Tough mother"; outermost tough fiberous sac around CNS
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Arachnoid layer
Means spider-like; Thin; delicate layer attached to pia mater by web-like filaments
70
Subarachnoid space
Between arachnoid layer and pia mater; Contains cerebrospinal fluid
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Pia mater
"Soft mother"; Innermost membrane layer; Applied directly to surface of brain
72
Peripheral Nervous System (PNS) Consists of:
12 pairs of cranial nerves; 31 pairs of spinal nerves
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Cranial nerves
Arise from brain
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Spinal nerves
Split off from spinal cord; One pair (left and right) exit between each pair of vertebrae
75
A nerve:
Is a bundle of axon fibers located outside CNS; Carries messages between CNS and various parts of body
76
Nerve root
Point where nerve is attached to CNS
77
Names of most nerves reflect:
Organ the nerve serves; Portion of body the nerve is traveling through
78
Neurons
Each nerve can carry information both to and from CNS; But any individual neuron can carry information in only one direction
79
Neuron Types:
Afferent neuron; Efferent neuron
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Afferent neurons
Also called sensory neurons; Carry sensory information from sensory receptor to CNS
81
Efferent neurons
Also called motor neurons; Carry activity instructions from CNS to muscles or glands
82
Divisions of PNS
Nerves of PNS are subdivided into two divisions:
Autonomic nervous system (ANS) & Somatic nerves.
Each division serves different area of body.
83
Autonomic Nervous System (ANS)
Control of involuntary or unconscious bodily functions
84
Autonomic Nervous System (ANS) divided into 2 branches:
Sympathetic branch & Parasympathetic branch
85
ANS: Sympathetic branch
"Fight or flight"
Stimulates body in times of stress and crisis.
Increases heart rate, dilates airways, increases blood pressure, inhibits digestion & stimulates production of adrenaline.
86
ANS: Parasympathetic branch
"Rest"
Serves as counterbalance for sympathetic nerves.
Causes heart rate to slow down, lowers blood pressure & stimulates digestion.
87
Nervous System
Coordinates all activity of body:
Receives info from sensory receptors.
Uses info to adjust activity of muscles & glands.
88
Myelin?
A fatty substance that acts as insulation for many axons.
89
Four sections of the brain:
Cerebrum
Cerebellum
Diencephalon
Brain stem
90
Cerebrum
Largest section.
Upper portion.
Processes thoughts, judgement, memory, association skills & ability to discriminate between items.
91
Cerebrum Frontal Lobe:
Most anterior lobe.
| Controls motor function, personality & speech.
92
Cerebrum parietal lobe:
Most superior portion.
Receives & interprets nerve impulses.
Interprets language.
93
Cerebrum occipital lobe:
Most posterior.
| Controls vision.
94
Cerebrum temporal lobe:
Left & right lateral portion.
| Controls hearing & smell.
95
Diencephalon:
Located below cerebrum.
| Contains 2 most critical areas: thalamus & hypothalamus.
96
Somatic Nerves
Mainly involved with conscious and voluntary activities of body.
Serve skin and skeletal muscles (carry information from sensory receptors of skin such as touch, temperature, pressure & pain).
Carry motor commands to skeletal muscles.
