Ch.14 Spinal Nerves/ Cord Flashcards
1
Q
Where does the Spinal Cord end?
A
L1Vertebrae
2
Q
(past L1) the inferior end tapers (narrows) to form the
A
conus medullaris
3
Q
How many pairs of Cervical Nerves
A
8 Pairs
4
Q
How many pairs of thoracic nerves are there
A
12 pairs
5
Q
How many pairs of sacred Nerves?
A
5 pairs
6
Q
How many pairs of coccygeal nerves
A
1 pair
7
Q
How many Spinal Nerves are there?
A
31
8
Q
spinal nerve roots extend inferiorly from the what
A
conus medullaris
9
Q
The spinal nerve roots that extend inferiorly from the conus medullaris are called the
A
Cauda Equina (the “horses tail”).
10
Q
Area deep to arachnoid through which CSF flows
A
Subarachnoid space
11
Q
Anterior horn
Lateral horn
Posterior horn
are the 3 horns of what
A
Gray matter
12
Q
Gray matter is composed of three horns:
(1/3)
(contains cell bodies of somatic motor neurons)
A
Anterior horn
13
Q
Gray matter is composed of three horns:
Contains cell bodies of autonomic motor neurons
only present in parts T1-L2
A
Lateral horn
14
Q
(contains sensory axons and cell bodies of interneurons)
A
Posterior horn
15
Q
What contains unmyelinated axons connecting left and right gray matter
A
Gray Commissure
16
Q
groups of cell bodies in CNS
A
Nuclei:
17
Q
Sensory nuclei in posterior horn contain what
A
interneurons
18
Q
What nuclei receive signals from skin, muscles and joints
site of synapse in posterior horn between somatosensory neurons and the interneurons
A
Somatic sensory nuclei:
19
Q
What nuclei receive signals from blood vessels, viscera
A
Visceral sensory nuclei:
20
Q
Motor nuclei in
anterior + lateral horns
contain what neurons?
A
Motor Nuerons
21
Q
Somatic motor nuclei (anterior) innervate what muscle?
A
skeletal muscle
22
Q
Autonomic motor nuclei (lateral) innervate what?
A
smooth muscle, heart, glands
23
Q
Sit between posterior gray horns and posterior median sulcus
(White matter is organized into three pairs of funiculi)
A
Posterior funiculus
24
Q
sits between anterior gray horns and anterior median fissure
(White matter is organized into three pairs of funiculi)
A
Anterior funiculus
25
Which pathways transmit ascending information from sensory receptors to the CNS
## Footnote
Spinal pathways are** sensory or motor
**
Sensory pathways
26
Which pathways transmit descending information from the brain to muscles and glands
## Footnote
Spinal pathways are** sensory or motor
Motor Pathway
27
most pathways decussate .... what does that mean?
## Footnote
Common pathway characteristics
axons cross midline so brain processes information for contralateral side
| uncrossed pathways work on the ipsilateral side of body
## Footnote
decussate = cross
28
uncrossed pathways work on what side of the body?
## Footnote
Common pathway characteristics
ipsilateral side of body
| (ipsilateral=same side)
29
Signals for proprioception, touch, temperature, pressure, pain
## Footnote
(2 Types) of General Sense Receptors = Somatic + Visceral
Somatic Sensory:
(Posterior)
30
located in skin and mucous membranes (monitor “texture”)
## Footnote
(Somatic Sensory: Signals) - Signals for proprioception, touch, temperature, pressure, pain
Tactile receptors:
31
What receptors are located within joints, muscles and tendons which detect stretch and pressure relative to position and movement of the skeleton and skeletal muscles.
## Footnote
(Somatic Sensory: Signals) - Signals for proprioception, touch, temperature, pressure, pain
Proprioceptors:
32
Sensory Pathways use a series of how many neurons to relay signal to brain)
2 or 3 neurons to relay signal to brain
33
Secondary (2nd order is a)
| Sensory Pathways (use a series of 2 or 3 neurons to relay signal to brai
## Footnote
primary (1st order) neuron
secondary (2nd order)
tertiary neurons (3rd order neuron)
Interneuron
34
1. Posterior funiculus-medial lemniscal pathway
2. Anterorlateral pathway
3. Spinocerebellar pathway
3 major types of what kind of Pathways
3 Major Types of **Somatosensory** Pathways
35
What pathway
transmits signals of proprioception and tactile receptors (touch, pressure, & vibration) with a 3 neuron chain?
Posterior Funiculus–Medial Lemniscal
Anterolateral (spinothalamic)
Spinocerebellar
Posterior Funiculus–Medial Lemniscal pathway
36
Within the cord, axon is in the posterior funiculus
fasciculus cuneatus (upper limb) or its fasciculus gracilis (lower limb)
| In what type of Pathway?
## Footnote
Posterior Funiculus–Medial Lemniscal
Anterolateral (spinothalamic)
Spinocerebellar
Posterior Funiculus–Medial Lemniscal pathway
37
transmits signals of proprioception and tactile receptors (touch, pressure, & vibration) with a 3 neuron chain
## Footnote
Posterior Funiculus–Medial Lemniscal
Anterolateral (spinothalamic)
Spinocerebellar
Posterior Funiculus–Medial Lemniscal pathway
38
transmits stimuli related to crude touch, pressure, pain, and temperature with a three-neuron chain
## Footnote
Posterior Funiculus–Medial Lemniscal
Anterolateral (spinothalamic)
Spinocerebellar
Anterolateral (spinothalamic) pathway
39
primary neuron relays signal from skin to spinal cord
secondary neuron relays signal from spinal cord to thalamus
(anterior spinothalamic tract or the lateral spinothalamic tract)
tertiary neuron relays signal from thalamus to cerebral cortex
## Footnote
Posterior Funiculus–Medial Lemniscal
Anterolateral (spinothalamic)
Spinocerebellar
Anterolateral (spinothalamic) pathway
40
# Anterolateral (spinothalamic) pathway
primary neuron relays signal from skin to what
spinal cord
41
# Anterolateral (spinothalamic) pathway
secondary neuron relays signal from spinal cord to what
thalamus
## Footnote
anterior spinothalamic tract or the lateral spinothalamic tract
42
# Anterolateral (spinothalamic) pathway
tertiary neuron relays signal from thalamus to what
cerebral cortex
43
transmits stimuli from proprioceptors to the cerebellum
Spinocerebellar pathway
44
axon ascends in either the
anterior spinocerebellar tract (trunk & lower limbs) or
posterior spinocerebellar tract (trunk & upper limbs)
Spinocerebellar pathway/
Anterolateral (spinothalamic) /
Posterior Funiculus–Medial Lemniscal
| in what type of pathway
Spinocerebellar pathway
45
# Spinocerebellar pathway
anterior spinocerebellar tract (trunk & lower or upper limbs)?
lower limbs
46
# Spinocerebellar pathway
posterior spinocerebellar tract (trunk & lower/upper limbs)
upper limbs
47
Motor is ascending or descending?
descending
48
What control effectors such as skeletal muscles
Motor (descending) pathways
| include at least two neurons
49
What pathway includes at least 2 neurons
Motor Pathways
1. Upper motor neuron
2. Lower motor neuron
50
# 1/2 Neuron of Motor (descending) pathways
Excite or inhibit lower motor neurons
Upper Motor Neurons
51
# 2/2 Neuron of Motor (descending) pathways
Always excites skeletal muscle
Upper/lower motor neurons
Lower Motor Neurons
52
What tract
-decussates (crosses) within medulla’
- innervate limb muscles for skill movements
lateral corticospinal tracts
53
The lateral corticospinal tract inervates what for skill movement
**- innervate limb muscles for skill movements**
| +crosses within medulla
54
How many Spinal nerves are there
## Footnote
formed from the union of an anterior root and a posterior root - dont need 2 know
31
55
anterior root is many axons of motor or sensory neurons
Motor
56
posterior root is many axons of motor or sensory neurons
Sensory
57
Posterior Ramus and Anterior Ramus are the 2 branches of the
Spinal Nerves
58
2 Branches of Spinal Nerves:
Posterior Ramus: : innervates the skin and deep muscles of the back
Anterior Ramus: innervates the anterior and lateral portions of the trunk and the limbs
59
What Branch of the Spinal Nerve ?
innervates the skin and deep muscles of the back
## Footnote
Innervate: supply (an organ or other body part) with nerves.
Posterior or anterior ?
Posterior Ramus:
60
What Branch of the Spinal Nerve ?
Innervates the anterior and lateral portions of the trunk and the limbs
## Footnote
Innervate: supply (an organ or other body part) with nerves.
Anterior Ramus:
61
A segment of skin supplied by single spinal nerve
-Can help localize damage to one or more spinal nerves
Dermatomes
62
What can help localize damage to one or more spinal nerves
Dermatomes
63
Four main plexuses occur bilaterally:
| Plexus: branching network of vessels or nerves.
cervical plexus
brachial plexus
lumbar plexus
sacral plexus
64
What Plexus is formed Formed from the anterior rami of C1–C4 spinal nerves
Cervical Plexus
65
What nerve is formed from rami of C3-C5; innervates the diaphragm
(C3-4-5 keeps the diaphragm alive)
Phrenic Nerve:
66
What cervicals keep the Diaphragm alive?
(Phremic Nerve)
C3
C4
C5- keep that diagraphm alive
| Phrenic Nerves - formed from Rami
67
What Plexus is Formed from the anterior rami of spinal nerves C5–T1.
Extends laterally from the neck into axilla (arm pit).
Innervates anterior and posterior parts of the upper limbs.
## Footnote
Innervate: supply (an organ or other body part) with nerves.
Brachial Plexuses
68
1. Axillary nerve: to deltoid,; sensory input from superolateral arm
2.Median nerve: sensory input from palmar side and dorsal tips of most fingers
3.Musculocutaneous nerve
4.Radial nerve:
5. Ulnar nerve: two medial fingers .
5 major terminal branches of Brachial Plexus
69
# 5 major terminal branches of Brachial Plexus
What nerve goes into the deltoid
gives sensory input from superolateral arm
Axillary Nerve
70
# 5 major terminal branches of Brachial Plexus
What Nerve gives sensory input from palm and dorsal tips from most fingers (except pinky)
Median Nerve
71
# 5 major terminal branches of Brachial Plexus
Which nerve is responsible for 2 medial fingers
Ulnar Nerve
72
# Brachial Plexus Injuries
difficulty abducting the arm
Axillary nerve injury
73
causes paralysis of extensor muscles of forearm, wrist, fingers
Radial nerve injury:
74
injury that may be compressed in Carpal Tunnel Syndrome
Median nerve injury
75
What plexus is Formed from the anterior rami of spinal nerves L1–L4.
Lumbar Plexuses
76
# Nerves from Lumbar Plexus
What Nerve innervates anterior thigh muscles
Femoral nerve
77
# Nerves from Lumbar Plexus
innervates medial thigh muscles
Obturator nerve:
78
What Plexus is Formed from the anterior rami of spinal nerves L4–S4.
Sacral Plexuses
79
What injury may be caused by herniated intervertebral disc
characterized by extreme pain down posterior thigh and leg
Sciatica (injury to sciatic nerve):
80
What is Sciatica caused by? Characterized by what?
intervertebral disc
characterized by extreme pain down posterior thigh and leg
81
What is a **rapid**, preprogrammed **involuntary** responses of muscles or glands to a stimulus.
Reflex
82
Is a Reflex volunatary or Involuntary?
Involuntary
83
1.A stimulus activates a sensory receptor
2. The sensory neuron transmits a nerve signal to the CNS
3. Information is processed by interneurons
4.Motor neuron transmits impulse to effector
5.Effector responds
5 Steps of Reflex
84
What are the 5 Steps of a Reflex?
1.A stimulus activates a sensory receptor
2. The sensory neuron transmits a nerve signal to the CNS
3. Information is processed by interneurons
4.Motor neuron transmits impulse to effector
5.Effector responds
85
sensory neurons synapse directly with motor neurons
| monosynaptic or polysynaptic:?
monosynaptic
86
One or more interneurons positioned between sensory and motor neurons
| monosynaptic or polysynaptic?
polysynaptic
87
receptor and effector are on the
1. same side of the body
2. opposite sides
| ipsilateral or contralateral:
Both
88
# These are What kind of Reflexes?
1. Stretch reflex
2. Golgi tendon reflex
3. Withdrawal reflex
4. Crossed-extensor reflex
4 Common Spinal Reflexes
89
Reflexive contraction of a muscle after it is stretched
Stretch (or tendon tap) is detected by a muscle spindle
## Footnote
These are What kind of Reflexes?
Stretch reflex
Golgi tendon reflex
Withdrawal reflex
Crossed-extensor reflex
Stretch reflex
90
# Stretch reflex: step 2
When stretched, what fires impulses that are conducted to the spinal cord
spindle’s sensory axon
91
# Stretch reflex: step 2
When stretched, spindle’s sensory axon fires what?
that are conducted to what part of the body?
impulses that are conducted to the spinal cord
92
# Stretch reflex:
In spinal cord, the sensory axon excites alpha motor neurons of the same muscle, causing what?
contraction (monosynaptic)
93
# Stretch reflex:
Are Contractions monosynaptic or polysynaptic?
monosynaptic
94
# Stretch reflex: step 5
Simultaneously, the sensory axon excites interneurons that inhibit motor neurons of antagonist muscle
monosynaptic or polysynaptic?
(polysynaptic reciprocal inhibition)
| Step 5
95
Which reflex Prevents muscles from contracting excessively
Golgi tendon organs detect excessive tension
## Footnote
What kind of Reflexes?
Stretch reflex
Golgi tendon reflex
Withdrawal reflex
Crossed-extensor reflex
Golgi tendon reflex
96
What detects excessive tension
Golgi tendon organs
97
What inhibit motor neurons of same muscle
+ prevents damage
Golgi tendon reflex
98
# Golgi tendon reflex
Which Reflex
Withdraws a body part away from a painful stimulus
Withdrawal reflex
99
Simultaneously, other interneurons reciprocally inhibit motor neurons of extensors (antagonist) so that extensor muscles (e.g., quadriceps) relax and withdrawal happens quickly
Withdrawal reflex
100
Which reflex
Allows the opposite side limb to support body weight while the hurt limb withdraws
Crossed-extensor reflex
101
# Reflex testing
: diminished or absent;
| Hypoactive reflexes or Hyperactive reflexes:
## Footnote
May indicate damage to spinal cord, or muscle disease, or damage to neuromuscular junction
Hypoactive reflexes
102
abnormally strong response
| Hypoactive reflexes or Hyperactive reflexes:
## Footnote
May indicate damage to brain or spinal cord, especially if accompanied by clonus
Hyperactive reflex:
103
May indicate damage to spinal cord, or muscle disease, or damage to neuromuscular junction
| Hypoactive reflexes or Hyperactive reflexes:
Hypoactive reflexes
104
May indicate damage to brain or spinal cord, especially if accompanied by clonus
| Hypoactive reflexes or Hyperactive reflexes:
Hyperactive reflex
