Peripheral Nervous System Flashcards
(109 cards)
1
Q
Links the CNS to the body and external environment.
A
Peripheral Nervous System (PNS)
2
Q
Detects sensory stimuli and deliver it to the CNS as sensory input.
A
Peripheral Nervous System
3
Q
What two main divisions is the PNS classified functionally into?
A
Sensory(Afferent) Division
Motor(Efferent) Division
4
Q
Consists of sensory(afferent) neurons that detect various sensory stimuli and bring them to the CNS
A
Sensory Division
5
Q
What are the two subdivisions of the Sensory Division?
A
Somatic sensory division
Visceral sensory division
6
Q
Detects sensory information from the skin and the structures of the musculoskeletal system
A
Somatic sensory division
7
Q
Relays sensory information from the organs of the abdominopelvic and thoracic cavities
A
Visceral sensory division
8
Q
Stimuli such as:
Touch Temperature Pain Muscle stretch Stimuli from the special senses
A
Somatic sensory division
9
Q
Stimuli such as:
Blood pressure
Stretching of urinary bladder
A
Visceral sensory division
10
Q
Consists of motor neurons that carry out the motor functions of the nervous system
A
Motor division
11
Q
What are the two subdivisions of the motor division?
A
Somatic motor division
Visceral motor division (ANS)
12
Q
Responsible for the body’s voluntary motor functions.
A
Somatic motor division
13
Q
Responsible for maintaining homeostasis through its control of the body’s involuntary motor functions.
A
Visceral motor division
14
Q
Made up of lower motor neurons that directly contact skeletal muscle fibers and trigger a contraction when stimulated by upper motor neurons in the CNS
A
Somatic motor division
15
Q
Neurons innervate cardiac muscle, smooth muscle, and glands
A
Visceral motor division (ANS)
16
Q
Divided into the sympathetic nervous system and the parasympathetic nervous system
A
Visceral motor division (ANS)
17
Q
Fight or flight division
A
Sympathetic nervous division
18
Q
Rest and digest division
A
Parasympathetic nervous division
19
Q
Main organs of the peripheral nervous system?
A
Peripheral nerves
20
Q
Consists of the axons of many neurons bound together by a common connective tissue sheath
A
Peripheral nerves
21
Q
Contain motor and sensory neurons
A
Mixed nerves
22
Q
Contain only sensory neurons
A
Sensory nerves
23
Q
Contain only motor neurons
A
Motor nerves
24
Q
Originate from the spinal chord and innervate structures below the head and neck. Carries visceral motor, somatic motor, and sensory signal to and from the spinal chord
A
Spinal nerves
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Two collection of axons that connect the PNS with the spinal chord gray matter
Anterior root and posterior root
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Contains motor neurons from the anterior horn that carries somatic and visceral motor signals from the CNS to skeletal muscles and glands
Anterior (ventral) Root
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Contain sensory neurons from the posterior horn that carries sensory signals from the PNS to the spinal chord.
Posterior (dorsal) Root
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Attach to the brain and mainly innervate structures of the head and neck
Cranial nerves
29
The connective tissue sheath that surrounds a peripheral nerve
Epineurium
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Bundles of axons
Fascicles
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The connective tissue sheath that surrounds a fascicle of a peripheral nerve
Perineurium
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The connective tissue sheath that surrounds an axon within a peripheral nerve
Endoneurium
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I Olfactory X Vagus
II Optic XI Accessory
XII Hypoglossal
III Oculomotor IX Glossopharyngeal
IV Trochlear
V Trigeminal
VI Abducens
VII Facial
VIII Vestibulochlear
The Cranial Nerves (12)
34
I Olfactory
II Optic
VIII Vestibulochlear
Sensory cranial nerves
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III Oculomotor
IV Trochlear
VI Abducens
XI Accessory
XII Hypoglossal
Motor cranial nerves
36
V Trigeminal
VII Facial
IX Glossopharyngeal
X Vagus
Mixed cranial nerves
37
A common problem in which facial nerve's motor root is impaired by a virus, tumor, trauma, or an unknown cause. Facial expression muscles becomes weak or paralyzed in the affected side. Problems with blinking, facial expressions, closing eyes, etc.
Bells Palsy
38
Fibers that travel to and from the posterior side of the body
Posterior ramus
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Fibers that travel to and from the anterior side of body and/or upper and lower limbs
Anterior ramus
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Carry somatic motor signals from the CNS to the skeletal muscles, and sensory signals from sensory receptors in the PNS spinal chord
Anterior and Posterior Rami
41
Autonomic fibers of the sympathetic nervous system that carries visceral motor signals from the ANS to the organs of the ventral body cavity
Ramus Communicans
42
A network of nerves that innervated a specific body region
Nerve plexuses
43
8 Cervical nerves (C1-C8)
12 Thoracic nerves (T1-T12)
5 Lumbar nerves (L1-L5)
5 Sacral nerves (S1-S5)
1 Coccygeal nerves (Co1)
The Spinal Nerves (31)
44
Consists of anterior rami C1-C4, small contributions from C5 and the Hypoglossal nerve; innervate skin of neck, portions of the head, chest, and shoulders
Cervical plexuses
45
Innervates the diaphragm and is the main nerve that drives breathing (3,4,5 to stay alive)
Phrenic nerve
46
Provides motor and sensory innervation to the upper limb, originates in the anterior rami spinal nerves C5-T1, inner eyes muscles of upper limbs
Brachial plexuses
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First structures formed in the brachial plexuses.
Superior trunk: C5 & C6
Middle trunk: C7
Inferior trunk: C8 & T1
Trunks
48
The trunks splits into an anterior division and posterior division that become
Cords
49
What are the five major nerves?
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Axillary nerve
Radial nerve
Musculocutaneous nerve
Median nerve
Ulnar nerve
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50
Motor to the deltoid and teres minor muscles. Sensory to the skin over the deltoid
Axillary nerve
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Motor to the triceps brachii muscle and the extensor muscles of the forearm and digits, sensory from the posterior hand
Radial nerve
52
Motor the anterior arm muscles; Sensory from skin over the lateral forearm
Musculocutaneous nerve
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Motor to the flexors in the forearm, certain intrinsic hand muscles; sensory from the skin of the anterior hand
Median nerve
54
The painful tingling after hitting your funny bone. Motor to flexor muscles in the forearm and most of the intrinsic hand muscles. Sensory to the fifth digit and the medial half of the fourth digit
Ulnar nerve
55
Arise from the anterior rami of L1-L4
Lumbar plexuses
56
Largest nerve of the anterior division of the lumbar plexuses. Motor to the thigh adductors and gracilis muscle. Sensory to the supermedial thigh
Obturator nerve
57
Motor to the anterior thigh muscles; sensory from the skin over the anterior thigh and leg
Femoral nerve
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Form from the anterior rami of spinal nerves L4-S4. Innervates structures of the pelvis and gluteal region as much of the lower extremity
Sacral plexuses
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Largest nerve in the sacral plexuses and longest in the body. Sensory to the skin of the posterior thigh
Sciatic nerve
60
Motor to the hamstring muscles, flexor muscles of leg, muscles of foot; and plantar foot muscles. Sensory from the skin over the posterior and lateral leg and foot
Tibial nerve
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Motor to the lateral leg muscles and anterior leg muscles; Sensory from the skin of the anteroinferior leg
Common fibular nerve
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Spasms of the diaphragm that cause a forceful inhalation of air
Hiccups
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The conversion of a stimulus into an electrical signal
Sensory transduction
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The region of the nerve ending where sensory transduction begins
Sensory receptor
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Specialized supportive cells that surround sensory receptors
Encapsulated nerve endings
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Lack specialized supportive cells and are naked
Free nerve endings
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When sodium ions enter the axoplasm, generating a temporary depolarization
Receptor potential
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Detects the initial stimuli, but ignore ongoing stimuli
Rapidly adapting receptors
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Respond to stimuli with constant action potentials that do not diminish with time
Slowly adapting receptors
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Close to the surface of the body. Detect stimuli originating outside the body, including an objects texture, temperature, and color; chemical odors in the air and e level of light.
Exteroceptors
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Lie generally within the body's interior; where they detect stimuli originating inside the body, including blood pressure, stretch of an organ such as a skeletal muscle or urinary bladder, the concentration of certain chemicals in body fluids, and body temperature
Interceptors
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Detect stimuli that mechanically deform the tissue through the opening of mechanically gated ion channels (light touch, vibration, stretch, and pressure)
Mechanoreceptors
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Detect thermal stimuli such as temperature changes
Thermoreceptors
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Detect the presence or concentration of certain chemicals in the body fluids or in the air
Chemoreceptors
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Detect light stimuli. (Found only in the eye)
Photoreceptors
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Detect pain stimuli
Nociceptor
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What are the six Mechanoreceptors?
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Merkel cell fibers
Tactile corpuscles
Ruffini endings
Lamellated corpuscles
Hair follicle receptors
Proprioceptors
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78
Detect discriminative touch with fine spatial resolution. (form and texture)
Merkel cell fibers
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A sensory receptor that detects light touch stimuli
Tactile corpuscle (meissner corpuscle)
80
Receptors that detect stretch and movement
Ruffini endings
81
Detect vibration and deep pressure
Lamellated corpuscle (pacinian corpuscle)
82
Respond to stimuli that causes the hair to bend (insect landing on arm)
Hair follicle receptors
83
Detect movement and position of a joint or body part (ligament or tendon)
Proprioceptors
84
What are the two types of Thermoreceptors?
Cold receptors (10 C and 40 C, 50-104 F)
Hot receptors (32 C and 48 C, 90-118 F)
85
The ability to discern that two nearby objects touching the skin are truly two distinct points, not one
Two-point discrimination threshold
86
Pain that originated in an organ is perceived as cutaneous pain
Referred pain
87
The skin divided in regions
Dermatomes
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Involved in the conscious planning of movement, initiate movement via lower motor neurons
Upper motor neurons
89
Motor neurons of the PNS that directly innervate skeletal muscles
Lower motor neurons
90
Large lower motor neurons that stimulate skeletal muscle fibers to contract by the excitation-contraction mechanism
X-motor neurons
91
Small lower motor neurons innervate muscle fibers called intrafusal fibers that are part of specialized stretch receptors
Y-motor neurons
92
What are the steps for control of movement by the nervous system?
1. Upper motor neurons in promoter cortex select motor program
2. Basal nuclei enable thalamus to stimulate upper motor neurons
3. Upper motor neurons stimulate lower ones
4. Lower motor neurons stimulate skeletal muscle
5. Sensory info relayed back to cerebellum in CNS, cerebellum sends instructions to upper motor neurons to modify movement as needed
93
Programmed, automatic response to stimuli
Reflexes
94
What is the reflex arc?
1. PNS detects and delivers stimuli to CNS
2. CNS integrates stimulus
3. PNS delivers motor response from CNS to effectors
95
A specialized bundle of intrafusal muscle fibers innervated by sensory neurons that detect stretch
Muscle spindles
96
Mechanoreceptors located within tendons near the muscle-tendon junction, that monitor the tension generated by a muscle contraction
Golgi tendon organs
97
A monsynaptic reflex triggered by muscle stretch, which produces an automatic contraction of the muscle to counter the stretch
Simple stretch reflex
98
Using a blunt object such as a reflex hammer or the medial surface of your hand to tap the patellar tendon (stretches the quadriceps femoris muscle of the thigh producing a quick knee jerk)
Patellar reflex/Knee-jerk reflex
99
A polysynaptic reflex that protects muscles and tendons from damage
Golgi tendon reflex
100
Withdraw limb from painful stimulus after Nociceptor detects the pain (touching something very hot or stepping on a tack)
Flexion/Withdrawal reflex
101
Provides balance and postural support to the unaffected/opposite limb when the flexion reflex is stimulated
Crossed-extension reflex
102
Triggered when the visceral sensory nerve endings of the glossopharyngeal nerve in the posterior throat are stimulated unilaterally
Gag reflex
103
Triggered when a stimulus reaches the somatic sensory receptors of the Trigeminal nerve in the thin outer covering of the eye called the cornea (when something comes in contact with your eye)
Corneal blink reflex
104
What plexuses is the phrenic nerve in?
Cervical plexuses
105
What plexuses is the axillary, radial, musculocutaneous, median, and ulnar nerves in?
Brachial plexuses
106
What plexuses is the femoral and obturator nerve in?
Lumbar plexuses
107
What plexuses is the tibial, sciatic, and common fibular nerves in?
Sacral plexuses
108
Motor to the muscles between the ribs and the abdominal muscles; sensory from the skin over the abdomen
Intercostal nerves
109
What happens during sensory transduction?
Ion channels open and receptor potential is generated
If receptor potential is large enough for the membrane to reach threshold, it triggers an action potential
