A&P Chapter 13 Flashcards
1
Q
What is cranial nerve I?
A
Olfactory
2
Q
What does cranial nerve I do?
A
Sense of smell
3
Q
What is cranial nerve II?
A
Optic
4
Q
What does cranial nerve II do?
A
Sense of vision
5
Q
What is cranial nerve III?
A
Oculomotor
6
Q
What does cranial nerve III do?
A
Controls muscles that move eye, lift eyelid, and change pupil diameter
7
Q
What is cranial nerve IV?
A
Trochlear
8
Q
What does cranial nerve IV do?
A
Controls superior oblique eye muscle
9
Q
What is cranial nerve V?
A
Trigeminal
10
Q
What does cranial nerve V do?
A
Somatic sensation from face, chewing movements
11
Q
What is cranial nerve VI?
A
Abducens
12
Q
What does cranial nerve VI do?
A
Controls lateral rectus muscle that abducts eye
13
Q
What is cranial nerve VII?
A
Facial
14
Q
What does cranial nerve VII do?
A
Controls muscles of facial expression and provides signals for taste from tongue
15
Q
What is cranial nerve VIII?
A
Vestibulocochlear
16
Q
What does cranial nerve VIII do?
A
Senses of hearing and equilibrium
17
Q
What is cranial nerve IX?
A
Glossopharyngeal
18
Q
What does cranial nerve IX do?
A
Taste and touch from tongue; control of a pharynx muscle
19
Q
What is cranial nerve X?
A
Vagus
20
Q
What does cranial nerve X do?
A
Visceral sensation; parasympathetic nerve to many organs of the body
21
Q
What is cranial nerve XI?
A
Accessory
22
Q
What does cranial nerve XI do?
A
Controls muscles of the neck and pharynx
23
Q
What is cranial nerve XII?
A
Hypoglossal
24
Q
What does cranial nerve XII do?
A
Controls tongue muscles
25
What is a nerve?
Cordlike organ of PNS
26
What makes up a nerve?
Bundle of myelinated and nonmyelinated peripheral axons enclosed by connective tissue
27
What are the two types of nerves?
Spinal or cranial
28
What dictates the two types of nerves?
Where they originate
29
Most nerves are mixtures of what?
Afferent/Efferent fibers and somatic/autonomic (visceral) fibers
30
How are nerves classified?
According to the direction they transmit impulses
31
What are mixed nerves
Sensory and motor fibers
32
Where does the impulse travel in mixed nerves?
To and from the CNS
33
Where does the impulse travel in sensory/afferent nerves?
Oly towards CNS
34
What is somatic afferent?
Sensory from muscle to brain
35
What is visceral afferent?
Sensory from organs to brain
36
Where does the impulse travel in motor/efferent nerves?
Only away from the CNS
37
What is somatic efferent?
Motor from brain to muscle
38
What is visceral efferent?
Motor from brain to organs
39
Mature neurons are _______
Amitotic
40
If the soma/cell body of the damaged nerve is intact, then the peripheral axon may regenerate in which nervous system
PNS
41
CNS axons do NOT _____
Regenerate
42
PNS axons can regenerate if damage is not ______
Severe
43
What is the process of PNS axons regenerating?
1. Axon fragments and myelin sheaths distal to injury degenerate (Wallerian degeneration); degeneration spreads down axon
2. Macrophages clean dead axon debris; Schwann cells are stimulated to divide
3. Axon filaments grow through regeneration tube
4. Axon regenerates, and new myelin sheath forms
44
What is visceral pain?
Stimulation of visceral organ receptors
45
How does visceral pain feel?
Vague aching, gnawing, and burning
46
What activates visceral pain?
Tissue stretching, ischemia, chemicals, muscle spasms
47
What is referred pain?
Pain from one body region perceived as coming from a different region
48
What causes referred pain?
Visceral and somatic pain fibers travel along the same nerves, so brain assumes stimulus comes from common (somatic) region
49
What is an example of referred pain?
Left arm pain during MI
50
Long -lasting or intense pain, such as a limb amputation can lead to what?
Hyperalgesia, chronic pain, and phantom limb pain
51
What is hyperalgesia?
Pain amplification
52
What is phantom limb pain?
Pain felt in limb that has been amputated
53
How is phantom limb pain prevented?
Epidural anesthesia is used during surgery to reduce phantom pain
54
How many pairs of spinal nerves are there?
31
55
How are mixed nerves named?
Point of issue from the spinal cord
56
Spinal nerves supply all body parts except what?
Head and part of the neck
57
How many pairs of cervical nerves are there?
8
58
How many pairs of thoracic nerves are there?
12
59
How many pairs of lumbar nerves are there?
5
60
How many pairs of sacral nerves are there?
5 pairs
61
How many pairs of the tiny coccygeal nerves are there?
1
62
What is the range of cervical nerves?
C1-C8
63
What is the range of thoracic nerves?
T1-T12
64
What is the range of lumbar nerves?
L1-L5
65
What is the range of sacral nerves?
S1-S5
66
What is the range of coccygeal nerves?
C0
67
Each spinal nerve has these two things:
Ventral roots and dorsal roots
68
What are the ventral roots associated with?
Motor
69
What are the dorsal roots associated with?
Sensory
70
The dorsal and ventral roots branch as rootlets, then join to form what?
Spinal nerve
71
What is ganglia?
Nerve cell bodies
72
How long are spinal nerves?
~1-2cm
73
Almost immediately after exiting the foramen, spinal nerves divide into what three branches?
1. Posterior/Dorsal ramus
2. Anterior/Ventral ramus
3. Meningeal branch
74
What is the posterior/dorsal ramus?
Smaller branch
75
What is the anterior/ventral ramus?
Larger branch
76
What is the meningeal branch?
Tiny branch that reenters vertebral canal to innervate meninges and blood vessels
77
What do rami communicantes contain?
Autonomic nerve fibers that join ventral rami in the thoracic region
78
What are dermatomes?
Segment of skin supplied by a single spinal nerve
79
Some dermatomes overlap in what regions?
Innervated
80
What is an example of a dermatome overlapping?
T10 dermatome = horizontal ring of skin around the umbilicus
81
What do dermatomes help?
Can help localize damage to one or more spinal nerves
82
What is an example of dermatomes helping localize damage?
Loss of sensation on medial arm and forearm indicates C8 damage
83
What type of pain are dermatomes involved in?
Visceral pain
84
What is a nerve plexus?
Network of interweaving antterior rami of spinal nerves
85
How many plexuses occur bilaterally?
4
86
What are the four main plexuses that occur bilaterally?
1. Cervical
2. Brachial
3. Lumbar
4. Sacral
87
What does not form plexuses?
Most thoracic spinal nerves and nerves S5-Co1
88
Individual rami branch _____
Repeatedly
89
What does it mean for damage when individual rami branch repeatedly?
Damage to one nerve or spinal segment does not deprive a muscle or skin region of all innervation
90
The anterior rami of nerves C1-C4 innervate what?
Anterior neck muscles, skin of neck, and portions of the head and shoulders
91
The rami of C3-C5 gives rise to what?
The phrenic nerve
92
What does the phrenic nerve innervate?
Diaphragm
93
What nerves are in the cervical plexus?
C1-C4
94
Which cervical nerve is not considered part of the cervical plexus?
C5
95
Irritation of the phrenic nerve causes what?
Spasms of the diaphragm
96
What are spasms of the diaphragm called?
Hiccups
97
If both phrenic nerves are severed, or the C3-C5 region of the spinal cord is destroyed, what happens to the diaphragm?
Diaphragm becomes paralyzed
98
What happens when the diaphragm becomes paralyzed?
Respiratory arrest occurs, victim requires mechanical respirators to stay alive
99
C3, C4, and C5 keeps the diaphragm ______
Alive
100
What are the 5 major terminal branches of the brachial plexus?
1. Axillary nerve
2. Median nerve
3. Musculocutaneous nerve
4. Radial nerve
5. Ulnar nerve
101
Where is the axillary nerve?
To deltoid and teres major muscles
102
What does the axillary nerve do?
Sensory input from superolateral arm
103
Where is the median nerve?
To most anterior forearm muscles and hand muscles
104
What does the median nerve do?
Sensory input from palmar side and dorsal tips of most fingers, except the pinkie
105
Where is the musculocutaneous nerve?
Anterior arm muscles (like the biceps brachii)
106
What does the musculocutaneous nerve do?
Sensory input from lateral forearm
107
Where is the radial nerve?
To posterior arm muscles (like the triceps brachii) and posterior forearm muscles
108
What does the radial nerve do?
Sensory input from posterior arm, forearm, and dorsolateral hand
109
Where is the ulnar nerve?
To anterior forearm muscles, most intrinsic hand muscles
110
What does the ulnar nerve do?
Sensory input from palmar and dorsal aspect of two medial fingers
111
Trauma to the radial nerve results in what?
Wrist drop
112
What is wrist drop?
Inability to extend the hand at the wrist
113
Improper use of a crutch can compress the ____ nerve and impairs it's blood supply
Radial
114
What is "Saturday night paralysis"?
An intoxicated person falls asleep with arm draped over the back of a chair or sofa edge, cutting off blood supply to the radial nerve
115
The ulnar nerve is very _____ to injury
Vulnerable
116
Severe or chronic damage to the ulnar nerve can lead to what?
Sensory loss, paralysis, and muscle atrophy
117
Severe or chronic damage to the ulnar nerve causes the hand to contort into what?
A clawhand
118
What is a clawhand?
Trouble making a fist and gripping objects. Little and ring fingers become hyperextended at the knuckles and flexed at distal interphalangeal joints
119
What is striking the "funny bone"?
The spot where the ulnar nerve rests against the medial epicondyle, causes the pinkie finger to tingle
120
What is the lumbar plexus?
L1-L4
121
What does the lumbar plexus do?
Innervates thigh, abdominal wall, and psoas muscle
122
What does the femoral merve do?
Innervates quadriceps and skin of anterior thigh and medial surface of the leg
123
What does the obturator nerve do?
Passes through obturator foramen to innervate adductor muscles
124
What is the sacral plexus?
L4-S4
125
What does the sacral plexus serve?
Buttock, lower limb, pelvic structures, and perineum
126
What is the sciatc nerve?
Longest and thickest nerve of the body
127
What does the sciatic nerve do?
Innervates hamstring muscles, adductor magnus, and most muscles in the leg and foot
128
What two nerves compose the sciatic nerve?
Tibial and common fibular
129
What is sciatica characterized by?
Stabbing pain radiating over the course of the sciatic nerve
130
What can injure the sciatic nerve?
A fall, disc herniation, or a badly placed injection into the buttock
131
If the sciatic nerve is transected, what happens to the leg?
Leg is nearly useless and cannot be flexed because the hamstrings are paralyzed
132
If the sciatic nerve is transected, what happens to the foot and ankle?
Foot and ankle cannot move at all, so foot drops into plantar flexion
133
What is footdrop?
Foot drops into plantar flexion
134
Recovery from sciatic nerve injury is usually ____ and _____
Slow and incomplete
135
For sciatic nerve injury below the knee, thigh muscles are _____
Spared
136
If the tibial nerve is injured, the paralyzed calf muscles cannot do what action?
Plantar flex foot
137
What creates a shuffling gait?
When the calf muscles cannot plantar flex the foot
138
What is a reflex?
Involuntary responses
139
What is required to initiate a reflex?
Stimulus
140
The response of a reflex is _____
Rapid
141
Only a few neurons are involved in ____
Reflexes
142
The response in reflexes are ______
Preprogrammed; always the same
143
Reflexes are _______
Involuntary; no intent or awareness of the reflex before it happens
144
A reflex is a ______ mechanism
Survival
145
Why is a reflex a survival mechanism?
We respond to a potentially detrimental stimulus immediately and awareness comes later
146
What are the five basic components of all reflex arcs?
1. Receptor
2. Sensory neuron
3. Integration center
4. Motor neuron
5. Effector
147
How can reflexes vary?
1. Spinal or cranial
2. Somatic or visceral
3. Monosynaptic or polysynaptic
4. Ipsilateral or contralateral
5. Innate or acquired
148
What does spinal or cranial mean?
Is the spinal cord or brain the reflex integration center?
149
What does somatic or visceral mean?
Is the effector a skeletal msucle or is it cardiac muscle, smooth muscle, a gland?
150
What does monosynaptic or polysynaptic mean?
Do sensory neurons synapse directly with motor neurons or are there interneurons in the reflex arc?
151
What does ipsilateral or contralateral mean?
Are receptors and effectors on the same side of the body or on opposite sides?
152
What does innate or acquired mean?
Are you born with the reflex or do you develop it after birth
153
What is an inborn (intrinsic) reflex?
Rapid, involuntary, predictable motor response to a stimulus
154
What are examples of an inborn reflex?
Maintain posture, control visceral activites
155
Inborn reflexes can be modified by what?
Learning and concious effort
156
What are learned (acquired) reflexes?
Result from practive or repetition
157
What is an example of learned reflexes?
Driving skills
158
Reflexes are classified functionally as what two things?
Somatic and autonomic
159
What do somatic reflexes do?
Activate skeletal muscle
160
What do autonomic (visceral) reflexes do?
Activate visceral effectors (like smooth or cardiac muscle or glands)
161
What is a monosynaptic reflex?
Direct communication between the sensory and motor neuron
162
What is an example of a monosynaptic reflex?
Stretch reflex
163
What is a polysynaptic reflex?
Interneuron facilitates sensory-motor communication
164
What is an example of a polysynaptic reflex?
Withdrawal reflex
165
Reflexes are useful for what?
Diagnoses
166
What can reflexes test?
Function of specific muscles, nerves, and spinal segments
167
What is a hypoactive reflex?
Diminished or absent
168
What does a hypoactive reflex indicate?
Damage to the spinal cord, muscle disease, or damage to neuromuscular junction
169
What is a hyperactive reflex?
Abnormally strong response
170
What does a hyperactive reflex indicate?
Damage to brain or spinal cord, especially if accompanied by clonus
171
What is clonus?
Rhythmic oscillating movements with reflex testing
172
Stretch reflexes can be hypoactive or absent if what happens?
Peripheral nerve damage or ventral horn injury has occured
173
Stretch reflexes are absent in who?
People with chronic diabetes mellitus or neurosyphilis, and during coma
174
Stretch reflexes can be hyperactive if what occurs?
Lesions of corticospinal tract reduce inhibitory effect of brain on the spinal cord
175
If the primary motor cortex or corticospinal tract is damaged, what happens to the plantar reflex?
Replaced by an abnormal reflex called the Babinski's sign
176
What is Babinski's sign?
Great toe dorsiflexes and smaller toes fan laterally
177
Why do infants exhibit Babinski's sign?
Their nervous systems are not completely myelinated
178
When do infants stop exhibiting Babinski's sign?
Until they are about a year old
