Exam 4, Chapter 13a - Somatic Motor (Part 1) Flashcards
1
Q
All neural structures outside the brain and spinal cord
A
Peripheral Nervous System
2
Q
Includes sensory receptors, peripheral nerves, associated ganglia, and motor endings
A
Peripheral Nervous System
3
Q
Provides links to and from the external environment
A
Peripheral Nervous System
4
Q
- cordlike organ of the PNS consisting of peripheral axons enclosed by connective tissue
- Connective tissue coverings include???
A
Structure of a Nerve
5
Q
-loose connective tissue that surrounds each individual axons
A
Structure of a Nerve
Endoneurium
6
Q
-coarse connective tissue that bundles fibers into fascicles (a bunch of axons)
A
Structure of a Nerve
Perineurium
7
Q
-tough fibrous sheath around an entire nerve (bunch of bunches of axons)
A
Structure of a Nerve
Epineurium
8
Q
Classification of Nerves
-carry impulse to the CNS
A
Classification of Nerves
sensory (afferent)
9
Q
Classification of Nerves
-carry impulses from CNS
A
Classification of Nerves
Motor (efferent)
10
Q
Classification of Nerves
-sensory & motor fibers carry impulses to & from CNS; most common type of nerve
A
Classification of Nerves
Mixed
11
Q
Classification of Nerves
- are mixed nerves
- carry somatic and autonomic (visceral) impulses
A
Classification of Nerves
Peripheral Nerves
12
Q
Classification of Nerves
- Somatic afferent
- Somatic efferent
- Visceral afferent
- Visceral efferent
A
Classification of Nerves
Peripheral Nerves
Four types of mixed nerves
13
Q
-nerves originate from the brain (cranial nerves) or spinal column (spinal nerves)
A
Peripheral nerves
14
Q
-Collections of neuron cell bodies with similar function associated with nerves in the PNS
A
Ganglion
plural=ganglia
15
Q
-Ganglia associated with afferent nerve fibers contain cell bodies of sensory neurons
A
Ganglion
plural=ganglia
16
Q
- lead into the spinal cord
A
Ganglion
(plural=ganglia)
Dorsal root ganglia
17
Q
- are associated with efferent nerve fiber;
- these are cell bodies of autonomic motor neurons involved with visceral innervation (names & details later in unit)
A
Ganglion
(plural=ganglia)
Autonomic ganglia
18
Q
- Damage to the neuron cell body is serious because mature neurons are amitotic.
- However, if the __ of a damaged nerve remains intact, damage can be repaired.
A
Regeneration of Nerve Fibers
soma
19
Q
-(occurs where an axon is damaged)
A
Regeneration of Nerve Fibers
Wallerian Degeneration
20
Q
- Axon becomes fragmented at injury site
- Macrophages – remove debris
A
Regeneration of Nerve Fibers
Wallerian Degeneration
21
Q
-follows degeneration and involves coordinated activity among:
A
Regeneration of Nerve Fibers
Regeneration
22
Q
- form regeneration tube;
- secrete growth factors
A
Regeneration of Nerve Fibers
Schwann cells
23
Q
-regenerate via filaments at a rate of 1.5 mm per day
A
Regeneration of Nerve Fibers
Axons
24
Q
- New myelin sheath forms
A
Regeneration of Nerve Fibers
Scwann cells
25
-Twelve pairs of c____ arise from the brain
Cranial Nerves
26
Arises from the olfactory epithelium (pseudostratified ciliated columnar)
Cranial Nerves
| I. Olfactory (S)
27
Passes through the cribriform plate of the ethmoid bone
Cranial Nerves
| I. Olfactory (S)
28
Fibers run through the olfactory bulb and terminate in the primary olfactory cortex (located in the deep temporal lobe, in the uncus);
Cranial Nerves
| I. Olfactory (S)
29
ipsilateral; do NOT synapse in the thalamus
Cranial Nerves
| I. Olfactory (S)
30
In order to correlate a smell with a memory, however, axons will pass through the thalamus
Cranial Nerves
| I. Olfactory (S)
31
Sensory: Functions solely by carrying afferent impulses for the sense of smell
Cranial Nerves
| I. Olfactory (S)
32
- Arises from the retina of the eye
Cranial Nerves
| II. Optic (S)
33
-Optic nerves pass through the optic canals (sphenoid bone) and converge at the optic chiasma (“X” cross-over) which sits just anterior to the pituitary gland
Cranial Nerves
| II. Optic (S)
34
-They continue to the thalamus where they synapse
Cranial Nerves
| II. Optic (S)
35
-From there, the optic radiation fibers run to the primary visual cortex (calcarine sulcus)
Cranial Nerves
| II. Optic (S)
36
-Sensory: Functions solely by carrying afferent impulses for vision
Cranial Nerves
| II. Optic (S)
37
-Somatic Motor: Fibers extend from the ventral midbrain (base of the cerebral peduncle), pass
through the superior orbital fissure (sphenoid), and go to the extrinsic eye muscles
Cranial Nerves
| III. Oculomotor (M)
38
Functions in raising the eyelid, directing the eyeball (4 of 6 muscles controlling eye movement:
-superior, inferior & medial rectus plus inferior oblique)
Cranial Nerves
| III. Oculomotor (M)
39
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Autonomic Motor (Parasympathetic): cell bodies are in the ciliary ganglia
- Functions in constricting the iris, and controlling lens shape for focusing
```
Cranial Nerves
| III. Oculomotor (M)
40
-Fibers emerge from the dorsal midbrain (corpora quadrigemina) and enter the orbits via the superior orbital fissures;
Cranial Nerves
| IV. Trochlear (M)
41
-innervate the superior oblique muscle (1 of 6 muscles controlling eye
movement)
Cranial Nerves
| IV. Trochlear (M)
42
-Somatic Motor: Functions primarily as a motor nerve that directs the eyeball
Cranial Nerves
| IV. Trochlear (M)
43
Largest cranial nerve; mixed nerve
Cranial Nerves
| V. Trigeminal (B)
44
Three divisions: ophthalmic (V1), maxillary (V2), and mandibular (V3)
Cranial Nerves
| V. Trigeminal (B)
45
Sensory: Afferent fibers run from the face, lips, gums, teeth & tongue [not taste buds] to the
pons via the superior orbital fissure (V1), the foramen rotundum (V2), and the foramen ovale (V3) [all in sphenoid]
Cranial Nerves
| V. Trigeminal (B)
46
Cell bodies converge at the large trigeminal ganglion
Cranial Nerves
| V. Trigeminal (B)
47
Somatic motor: Mandibular division (V3) supplies motor fibers for mastication (chewing)
Cranial Nerves
| V. Trigeminal (B)
48
-Fibers leave the inferior pons and enter the orbit via the superior orbital fissure
Cranial Nerves
| VI. Abducens (M)
49
- innervate the lateral rectus muscle (1 of 6 muscles controlling eye movement)
Cranial Nerves
| VI. Abducens (M)
50
- Somatic Motor: Functions primarily as a motor nerve that directs the eyeball
Cranial Nerves
| VI. Abducens (M)
51
```
Fibers leave the pons, travel through the internal acoustic meatus, and emerge through the
stylomastoid foramen (in temporal bone) to the lateral aspect of the face
```
Cranial Nerves
| VII. Facial (B)
52
Mixed nerve with five major branches: temporal, zygomatic, buccal, mandibular, cervical)
Cranial Nerves
| VII. Facial (B)
53
Somatic motor: Functions as a motor nerve for muscles of facial expression
Cranial Nerves
| VII. Facial (B)
54
```
Autonomic motor (Parasympathetic): Functions in transmittal of motor impulses to lacrimal,
nasal and salivary glands
```
Cranial Nerves
| VII. Facial (B)
55
Sensory: Afferent fibers from the taste buds in the anterior two-thirds of the tongue
Cranial Nerves
| VII. Facial (B)
56
Sometimes referred to as Auditory Vestibular Nerve
Cranial Nerves
| VIII. Vestibulocochloear (S)
57
Fibers arise from the hearing and equilibrium apparatus of the inner ear, pass through the
internal acoustic meatus, and enter the brainstem at the pons-medulla border
Cranial Nerves
| VIII. Vestibulocochloear (S)
58
Two divisions – cochlear (hearing) and vestibular (balance)
Cranial Nerves
| VIII. Vestibulocochlear (S)
59
Sensory: Primarily functions in hearing and balance
Cranial Nerves
| VIII. Vestibulocochloear (S)
60
Fibers emerge from the medulla, leave the skull via the jugular foramen, and run to the throat
Cranial Nerves
| IX. Glossopharyngeal (B)
61
Somatic Motor – Motor nerve for the posterior tongue and pharynx (lifts during swallowing)
Cranial Nerves
| IX. Glossopharyngeal (B)
62
Autonomic Motor (Parasympathetic) - Provides motor fibers to the parotid salivary gland,
Cranial Nerves
| IX. Glossopharyngeal (B)
63
Sensory – Afferent fibers conduct taste and general sensory impulses from the posterior tongue and pharynx (swallow & gag reflex),
carotid body chemoreceptors (monitors O2 & CO2,
ultimately affects
breathing rate/depth),
carotid sinus baroreceptors (monitors blood pressure)
Cranial Nerves
| IX. Glossopharyngeal (B)
64
The only cranial nerve that extends beyond the head and neck
Cranial Nerves
| X. Vagus (B)
65
Fibers emerge from the medulla via the jugular foramen & descends into the thorax and
abdomen
-mixed nerve that serves as a major parasympathetic pathway for the body
Cranial Nerves
| X. Vagus (B)
66
```
Autonomic motor (Parasympathetic) - Provides motor fibers to the heart, lungs & visceral organs
and functions in regulation of heart rate, breathing and digestive system activity
```
Cranial Nerves
| X. Vagus (B)
67
Somatic motor – Functions as a motor nerve for pharynx & larynx skeletal muscle (swallowing)
Cranial Nerves
| X. Vagus (B)
68
Sensory: Afferent fibers from the pharynx and taste buds of posterior tongue; afferent fibers from the thoracic and abdominal viscera; carotid & aortic body chemoreceptors (monitors O2 & CO2);
aortic arch baroreceptors (monitors blood pressure)
Cranial Nerves
| X. Vagus (B)
69
-Formed from C1 – C5 ventral rootlets (no cranial origin); this root passes upward into the cranium via the foramen magnum and then leaves the cranium via the jugular foramen
Cranial Nerves
| XI. Accessory (M)
70
Primarily a somatic motor nerve
Cranial Nerves
| XI. Accessory (M)
71
Supplies fibers to the larynx, pharynx, and soft palate
Cranial Nerves
| XI. Accessory (M)
72
Innervates the trapezius and sternocleidomastoid, which move the head and neck
Cranial Nerves
| XI. Accessory (M)
73
Fibers arise from the medulla and exit the skull via the hypoglossal canal (occipital bone, just
lateral to the foramen magnum) to the tongue
Cranial Nerves
| XII: Hypoglossal (M)
74
Somatic motor: Innervates both extrinsic and intrinsic muscles of the tongue, which contribute to swallowing and speech
Cranial Nerves
| XII: Hypoglossal (M)
75
named according to their point of exit from the intervertebral foramen
Spinal Nerves
76
C1-C7 nerves are named as they exit SUPERIOR to the vertebrae for which they are named
Spinal Nerves
77
nerve exits below C7 vertebra (so, C8 nerve exits at the C7-T1 intervertebral foramen)
Spinal Nerves
| C8
78
All others leave the intervertebral foramen ___ the named vertebra
Spinal Nerves
| below
79
Thoracic?
Lumbar?
Sacral?
Coccygeal?
```
Spinal Nerves
12 thoracic (T1-T12);
5 Lumbar (L1-L5);
5 Sacral (S1-S5);
1 Coccygeal (C0)
```
80
Each spinal nerve connects to the spinal cord via a
Spinal Nerves
| ventral and a dorsal root
81
Each root forms from a series of ___ that attach to the spinal cord
Spinal Nerves
| rootlets
82
arise from the ventral horn and contain motor (efferent) fibers
Spinal Nerves
| Ventral roots
83
Composed of somatic motor & autonomic motor
Spinal Nerves
| Ventral roots
84
contain sensory afferent fibers that arise from sensory neurons in the dorsal root ganglia and conduct impulses from peripheral receptors
Spinal Nerves
| Dorsal roots
85
Roots join together to form the ____ just distal to the dorsal root ganglion & just
before exiting from the vertebral column
Spinal Nerves
86
Each ___ is very short (only 1-2 cm)
Spinal Nerves
87
Nerve carries both
Spinal Nerves
| Afferent and Efferent Fibers
88
The length of the spinal roots in the ___ and ___ region is significant, as they extend inferiorly as the cauda equina before joining together as a nerve
Spinal Nerves
| Lumbar and Sacral
89
the spinal roots are ___ to the nerve & are either sensory or motor
Spinal Nerve
| medial
90
Immediately upon exiting the intervertebral foramen, the short spinal nerves branch into three or four distal rami (all with mixed fibers);
Spinal Rami
91
Point: the mixed fiber spinal rami are ___ to the nerve
Spinal Rami
| Lateral
92
Innervates the posterior trunk via several branches in a simple segmental pattern
Spinal Rami
| Small Dorsal Ramus
93
T1-T12 innervate the thorax as intercostal nerves (simple segmental pattern)
Spinal Rami
| Larger ventral ramus
94
Intercostal nerves supply muscles of the ribs, anterolateral thorax & abdominal wall
Spinal Rami
| Larger ventral ramus
95
A portion of T1 and all other ventral rami form complex plexus networks (additional detail
below) which primarily innervate the limbs
Spinal Rami
| Larger ventral ramus
96
Re-enters the vertebral canal to innervate the spinal cord meninges and blood vessels
Spinal Rami
| Tiny Meningeal branch
97
are at the base of the ventral rami in the thoracic region
Spinal Rami
| Rami communicantes
98
These branches form the sympathetic trunk ganglia and carry autonomic motor fibers
Spinal Rami
| Rami communicantes
99
LOOK AT RAMI DIAGRAM
Spinal Rami
| Ok.
100
All ventral rami (motor) except T2-T12 branch and form interlacing nerve networks called
Nerve Plexuses
101
located lateral to the vertebral column in the cervical, brachial, lumbar & sacral regions
Nerve Plexuses
102
Each resulting branch of a ___ contains fibers from several spinal nerves
Nerve Plexuses
103
Fibers travel to the periphery via
Nerve Plexuses
| several different routes
104
Each muscle receives a nerve supply from
Nerve Plexuses
| more than one spinal nerve
105
Damage to one spinal segment (can/not?) t completely paralyze a muscle
Nerve Plexuses
| cannot
106
Innervation of a Joint
any nerve serving a muscle that produces movement at a joint also innervates the joint itself and the skin over the joint
Nerve Plexuses
| Hilton's law
107
Innervates
| M/S fibers for diaphragm (respiration)
Cervical Plexus
| Phrenic Nerve
108
Innervates
| Sternocleidomastoir muscle & Trapezius
```
Cervical Plexus
Accessory Nerve (XI)
```
109
Formed by ventral rami of C1-C4
Cervical Plexus
110
Formed by ventral rami of: C5-C8 and T1
Brachial Plexus
111
Roots
Trunks
Divisions
Cords
Brachial Plexus
112
```
Innervates
deltoid muscle (shoulder abduction)
```
Brachial Plexus
| Axillary Nerve
113
Innervates
| elbow flexors
Brachial Plexus
| Musculocutaneous Nerve
114
Innervates
- most anterior forearm muscles (wrist flexion & abduction)
- carpal tunnel syndrome
Brachial Plexus
| Median Nerve
115
Innervates
| -few anterior forearm muscles (wrist flexion and adduction)
Brachial Plexus
| Ulnar nerve
116
-Largest branch of the brachial plexus
Innervates
-all extensor muscles of the upper limb
Brachial Plexus
| Radial nerve
117
Formed by ventral rami of: L1-L4
Lumbar Plexus
118
-Largest nerve of LUMBAR Plexus
Innervates
-anterior thigh muscles
Lumbar Plexus
| Femoral Nerve
119
Innervates
| -adductor muscles in the thigh
Lumbar Plexus
| Obturator Nerve
120
Formed by ventral rami of: L4-S4
Sacral Plexus
121
Actually two nerves wrapped in sheath
| -Thickest/longest nerve in body
Sacral Plexus
| Sciatic nerve
122
Innervates
| muscles of the back of thigh, leg and foot
Sacral Plexus
| Tibial Nerve
123
Innervates
| anterior & lateral muscles in the lower leg
Sacral Plexus
| Common Peroneal nerve
124
the area of skin innervated by the cutaneous branches of a single spinal nerve
Dermatomes
125
All spinal nerves except C1 participate in
Dermatomes
126
mapping is used clinically to determine specific nerve deficit: typical testing includes light touch and pin prick.
Dermatomes
127
Takes place at a neuromuscular junction
Motor Endings / Innervations of Skeletal Muscle
128
This junction is the synapse that is formed by the somatic motor efferent axon terminals
and the muscle fibers
Motor Endings / Innervations of Skeletal Muscle
| Neuromuscular Junction
129
is the neurotransmitter that diffuses across the neuromuscular junction
synaptic cleft
Motor Endings / Innervations of Skeletal Muscle
| Acetylcholine
130
___ binds to receptors resulting in:
- Movement of Na+ and K+ across the membrane
- Depolarization of the interior of the muscle cell
- An end-plate potential that triggers an action potential
Motor Endings / Innervations of Skeletal Muscle
| Acetylcholine (Ach)
