Spinal And Autonomic Nerves Flashcards
1
Q
Spinal cord neuropathology
A
Myelopathy
2
Q
Peripheral nerve neuropathology
A
Mononeuropathy or polyneuropathy; peripheral neuropathy
3
Q
Signs suggestive of peripheral neuropathy
A
Hyporeflexia, hypotonia
Denervation atrophy
Unilateral motor and sensory deficits
Normal function cranial and caudal to nerve lesion site
4
Q
4 parts of a spinal nerve
A
Roots
Main trunk
4 primary branches
Peripheral branches of primary branches
5
Q
Spinal nerve roots
A
Location: vertebral canal
Associated with the spinal cord despite belonging to PNS
6
Q
Dorsal spinal nerve roots
A
Sensory; after end
7
Q
Ventral spinal nerve roots
A
Motor; efferent
8
Q
Main trunk of a spinal nerve
A
Very short
Location: intervertebral foramen
9
Q
Spinal nerve formula
A
Determined by total number of vertebrae plus one
Dog: C8 T13 L7 S3 Cd5
Horse: C8 T18 L6 S5 Cd7
Bovine: C8 T13 L6 S5
10
Q
First cervical nerve
A
Emerges through the lateral vertebral foramen in the atlas
11
Q
Second cervical nerve
A
Exits through the lateral vertebral foramen of the axis in horses
Emerges through the intervertebral foramen b/w the first and second vertebrae in the dog
12
Q
Eighth cervical nerve
A
Runs through the intervertebral foramen between the seventh cervical and first thoracic vertebrae
13
Q
What is important to know about the cervical region with regards to spinal cord and vertebral segments?
A
The cervical region has one more spinal cord segment than vertebral segments
14
Q
How many cervical nerves are in the horse?
A
8
15
Q
How many cervical vertebrae are in the horse?
A
7
16
Q
What are the four primary branches in a spinal nerve?
A
Dorsal
Ventral
Meningeal
Communicating
17
Q
What do dorsal primary branches of spinal nerves supply?
A
Dorsal axial (epaxial) muscles
Skin over the dorsal and dorsolateral body
18
Q
Which primary branch of a spinal nerve is the largest?
A
Ventral
19
Q
What do ventral primary branches of spinal nerves supply?
A
Ventral axial (hypaxial) muscles
Muscles of ventral and ventrolateral regions including:
- thoracic limbs
- pelvic limbs
Skin over the ventral and ventrolateral regions
20
Q
What forms the brachial plexus?
A
Ventral primary branches of C6-T1/2 intermingling
21
Q
Are there ganglia or synapses in the brachial plexus?
A
No
22
Q
Where do named peripheral nerves come off?
A
Brachial plexus
23
Q
What forms the lumbosacral plexus?
A
L4-S4 ventral primary branch intermingling
24
Q
What does the lumbosacral plexus supply?
A
Pelvic limb
Perineal region
25
Which primary branch of a spinal nerve is very small and difficult to see?
Meningeal branch
26
What do the meningeal primary branches of spinal nerves supply?
Meninges (coverings of the spinal cord)
Blood vessels in the vertebral canal
Intervertebral discs (sinovertebral nerve)
27
Which primary branch of a spinal nerve is indicated in back pain?
Meningeal
28
Where does the communicating primary branch of a spinal nerve run?
Main trunk --> sympathetic trunk and chain ganglia
29
Which primary branch of a spinal nerve is associated with visceral function (ANS)?
Communicating
30
Where is a somatic structure associated?
Body wall
- skin
- SC tissue
- skeletal muscle
- joints
- tendons
- etc.
31
Where is the visceral structure associated?
Internal organs
Smooth muscle
Cardiac muscle
Glands
32
What do we call peripheral nerves that go to skin only?
Cutaneous nerves
33
What do we call peripheral nerves that go to muscle only?
Muscle nerves
34
What do we call most large peripheral nerves?
Mixed nerves
We call them this because they go to both skin and muscle
The femoral nerve is a mixed nerve which branches peripherally into both cutaneous and muscle nerves
35
Brain neuropathology
Encephalopathy
36
Functional components of cutaneous nerves
Somatic efferents from receptors in skin and SC tissue
Visceral afferents from receptors in blood vessels
Visceral efferents: postganglionic sympathetic fibers which have their cell bodies in chain ganglia.
37
What do postganglionic sympathetic fibers supply?
Smooth muscles of blood vessels
Erector pilae muscles associated with hairs
Sweat glands
38
Why don't cutaneous peripheral nerves have somatic efferents?
B/c there is no striated muscle
39
The area of skin supplied by a given cutaneous nerve is defined as a?
Cutaneous area
40
What are the two areas within a cutaneous area?
Overlap zones (OZ)
Autonomous zones (AZ)
41
What do we call the zone of a cutaneous area that is supplied by more than one cutaneous nerve?
Overlap zone (OZ)
42
What do we call the zone of a cutaneous area that is supplied by only one cutaneous nerve?
Autonomous zone (AZ)
43
What represents the region of anesthesia resulting from severe damage to one peripheral nerve and is the area of most diagnostic value in determining the level of nerve damage in a patient?
Autonomous zone (AZ) of a cutaneous area
44
What do we call all of the skin associated with a given spinal nerve?
Dermatome
45
Where do the dorsal cutaneous branches that supply the neck, thorax, abdomen, and rump originate in the cervical, thoracic, and lumbar spinal nerves?
Dorsal primary branch
46
Where do the ventral and lateral cutaneous branches that supply the neck, thorax, abdomen, and rump originate in the cervical, thoracic, and lumbar spinal nerves?
Ventral primary branch
47
What distinguishes muscle nerves from cutaneous nerves?
Muscle nerves have somatic efferents, and cutaneous nerves do not, because cutaneous nerves do not supply striated muscle.
48
From where can muscle nerves originate?
Dorsal or ventral primary branches
NOT communicating or meningeal branches
49
What do we call a nerve that can give rise to both muscle and cutaneous nerves dismally?
Mixed nerve
50
Which nervous system supplies motor nerves to glands, cardiac muscle, and visceral muscle, also known as smooth muscle?
Autonomic nervous system
51
The autonomic nervous system provides dual innervation in a two-division, two-neuron motor system, and the two divisions are antagonistic in action. What are the dual innervation a?
Sympathetic and parasympathetic
52
A small, myelinated nerve fiber belonging to the autonomic nervous system which has its cell body located in the CNS and its axon and termination in a peripheral autonomic ganglion/
Preganglionic fibers
53
An unmyelinated nerve fiber belonging to the ANS which has its cell body located in the PNS, and specifically in an autonomic ganglion at one of three general locations
Postganglionic fiber
54
Ganglia that is sympathetic only and alongside the vertebral column within the sympathetic trunk
Paravertebral ganglia
55
Ganglia in an intermediate location (sym and parasym) between the sympathetic trunk and an effector organ
Prevertebral ganglia
56
Ganglia that are mostly parasympathetic and mostly intrinsic neural plexuses of the gastrointestinal, respiratory, and urogenital tracts
Terminal ganglia
57
Part of the ANS also known as the craniosacral division; originates in the brain stem with the cranial nerves and in the sacral regions of the spinal cord
Parasympathetic
58
Part of the ANS that is also called thoracolumbar; originates in the thoracic and upper lumbar spinal cord
Sympathetic
59
Breakdown of parasympathetic ganglia
NO chain
Few prevertebral
Mostly terminal
60
Breakdown of sympathetic ganglia
Few terminal
Some prevertebral
Mostly chain
61
Do parasympathetic postganglionic fibers go to cardiac muscle, glands, and smooth muscles of the eye, digestive, respiratory, and urogenital systems?
Yes
62
Do parasympathetic postganglionic fibers go to sweat glands, smooth muscles of the skin (erector pilae muscles), or blood vessels of the head, body wall, and extremities?
No
63
Do postganglionic parasympathetic fibers run in cranial and sacral nerves?
Yes
64
Do postganglionic sympathetic fibers go to cardiac muscle, all glands, and all smooth muscles of the body?
Yes
65
Where do sympathetic postganglionic fibers run?
All spinal nerves and their peripheral branches
| Peripheral branches of most cranial nerves
66
Are preganglionic parasympathetic or sympathetic fibers longer?
Parasympathetic
67
Are postganglionic parasympathetic or sympathetic fibers longer?
Sympathetic
68
Which system is "rest and digest" and operates locally in specific organ locations?
Parasympathetic
69
Which system is "fight or flight" and operates globally in a mass response?
Sympathetic
70
What neurotransmitter is usually released from cholinergic parasympathetic postganglionic fibers?
Acetylcholine (Ach)
71
What neurotransmitter is usually released from adrenergic sympathetic postganglionic fibers?
Norepinephrine (NE)
72
What cholinergic receptors are present for neurotransmitter Ach?
Nicotinic
Muscarinic
73
Where are nicotinic receptor sites found?
Pre-postganglionic junctions of both sympathetic and parasympathetic systems
All somatic neuromuscular junctions (between somatic efferents and skeletal muscle)
74
Where are Muscarinic receptor sites found?
Parasympathetic postganglionic- effector junction
75
What is the neurotransmitter at sympathetic postganglionic-effector organ junctions?
Norepinephrine
76
What adrenergic receptors are on effector organs?
Alpha adrenergic (a1 and a2)
Beta adrenergic (b1 and b2)
77
Where are preganglionic cell bodies supplying the head and neck regions generally located?
The lateral horn of T1-T5
78
How far does the sympathetic trunk extend?
C1-Cd1
79
In the supply to the neck: Preganglionic fibers synapse with postganglionic fibers in the ___ ganglion (fused chain ganglia from __-__). The postganglionic fibers reach the cervical spinal nerves (__-__) via the ___ nerve. Fibers leave the nerve near each spinal nerve, travel through the ___ branch to the main trunk and then distribute themselves in the other three primary nerve branches for distribution to their effector organs of the neck region.
Cervicothoracic
C7-T2
C3-C8
Vertebral
Communicating
80
Sympathetic Supply to the head and C1 and C2 regions: Preganglionic fibers pass through the ___ ganglion and travel cranially in the ___ trunk in the neck to eventually synapse with their postganglionic fibers in the ___ ganglion (fused chain ganglia of ___-___). Postganglionic fibers destined for the C1 and C2 body region travel back to the main trunk of C1 and C2 via the ___ branch. Postganglionic fibers destined for the head travel initially along a plexus surrounding the ___ artery and are distributed distally along branches of most cranial nerves (except ___, ___, and ___) and smaller blood vessels
Cervicothoracic
Vagosympathetic
Cranial cervical
C1-C2
Communicating
Internal carotid
I, II, and VIII
81
Serious damage to the vagosympathetic trunk in the cervical region will eliminate the Preganglionic supply to the ___ ganglion and the entire ___ supply to the head will be essentially removed. This condition is known as ___ in particular as it relates to the ___. It is often a sequelae to avulsion of the roots of the spinal nerves contributing to the ___.
Cranial cervical
Sympathetic
Horner's syndrome
Eye
Brachial plexus
82
5 classical signs of Horner's syndrome
Constriction of pupil on the affected side (due to parasympathetics taking over)
Nictitating membrane prolapse over the eye (due to paralysis of the smooth muscle retracting it)
Partial ptosis (drooping) of the upper eyelid (due to relaxation of the smooth muscle that retracts the lid)
Enophthalmia (recession of the eyeball within the orbit)
Anhidrosis (lack of sweating) on affected side (because sympathetics supply sweat glands. This is Muscarinic Ach in most species, but in the horse the neurotransmitter is believed to be norepinephrine. Thus, in horses with Horner's syndrome, there will be excessive sweating in the affected side.
83
In horses with Horner's syndrome, the postganglionic neurotransmitter to the sweat glands is believed to be ___. This means that an affected horse with the syndrome will ___ on the affected side.
This response is caused by ___ (a phenomenon caused by the proliferation of adrenergic receptors on sweat glands)
Norepinephrine
Sweat
Denervation supersensitivity
84
Sympathetic Preganglionic cell bodies supplying the thoracic cavity are located in the lateral horn of ___-___
T1-T11
85
Sympathetic supply to the thoracic cavity: Preganglionic fibers to the heart, bronchi, and ___ travel cranially in the ___ trunk and synapse in the ___ ganglion (fused chain ganglia of ___-___) and the ___ ganglion. Postganglionic fibers travel to the visceral thoracic organs via the ___ nerves and neural plexuses around arteries. Some Preganglionic fibers synapse in the ___ ganglia.
Lungs
Sympathetic
Middle cervical
C3-C7
Cervicothoracic
Cardiosympathetic
Chain
86
Sympathetic preganglionic cell bodies supplying the abdominal and pelvic cavities and the genitalia are located primarily in the lateral horn of ___-___
T8-L3
87
Sympathetic supply to the abdominal/pelvic cavities and genitalia: Preganglionic fibers enter the sympathetic trunk and run ___ and either--
(I) leave the trunk in the ___ nerves, which perforate the ___ and enter the abdominal cavity, or--
(II) leave the sympathetic trunk in the lumbar region (___-___) in the ___ nerves.
These fibers synapse in any of a number of ___ ganglia. Examples are the celiacomesenteric, adrenal, aorticorenal, caudal mesenteric ganglia. Postganglionic fibers travel to their respective effector organ via ___ plexuses.
Preganglionic fibers destined for the pelvic and urogenital organs synapse in the ___ ganglion and the postganglionic fibers leave via the ___ nerves, pass through the pelvic plexus, and supply their assigned effectors via arterial plexuses and small nerve bundles. Many preganglionics destined for the external genitalia synapse in the ___ plexus or ___ ganglia.
Caudally
Thoracic splanchnic
Diaphragm
L1-L4
Lumbar splanchnic
Prevertebral
Arterial
Caudal mesenteric
Hypogastric
Pelvic
Sacral chain
88
Sympathetic fibers supplying the body wall in the T1-L3 regions, including the thoracic limb: Preganglionic fibers leave the main trunk via the ___ branch, then enter and synapse in the ___ ganglion of that segment. Postganglionic fibers run back through the same branch and are distributed to the ___ through the other 3 primary spinal branches
Communicating
Chain
Body wall
89
Sympathetic fibers supplying the body wall in the L4-Cd region, including the pelvic limb: Pregnaglionic cell bodies are usually located in the lateral horn of ___-___ segments and enter the sympathetic trunk to synapse in the chain ganglia of ___-___. Postganglionic fibers run back to the spinal nerve of that segment via the ___ branch for distribution to the body wall.
L1-L3
L4-S1
Communicating
90
Parasympathetic fibers supplying the head region: Preganglionic fibers travel peripherally in cranial nerves ___, ___, ___, and ___.
III, VII, IX, X
91
Parasympathetic supply to the visceral organs as far distally as the transverse colon: Preganglionic fibers run out of the brain stem in the ___ nerve, descend caudally in the ___ trunk, pass through the thorax in the dorsal and ventral ___ trunks, and reach the ___ plexuses (celiacomesenteric, caudal mesenteric, etc.) through which they pass without synapsing. Eventually, the preganglionic fibers synapse in a ___ ganglion (such as the myenteric plexus) in the effector organ.
Postganglionic fibers are very ___ and run from the ___ ganglion to the effector.
Vagus
Vagosympathetic
Vagal
Abdominal autonomic
Terminal
Short
Terminal
92
Parasympathetic fibers supplying visceral organs distal to the transverse colon: Preganglionic fibers have cell bodies in ___-___ in the horse. They travel through the ___ nerve, which descends in the pelvic cavity to form the ___ plexus. Most preganglionics synapse here, but others pass through to eventually synapse in a ___ ganglion.
S3-S4
Pelvic
Pelvic
Terminal
