Term
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Definition
Involuntary motor system
Innervates smooth muscle and glands (sweat and salivary) |
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Term
| ANS Functional Sub-divisions |
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Definition
Parasympathetic – Craniosacral (rest/digest)
Sympathetic – thoracolumbar (fight/Flight)
Each organ receives dual innervation |
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Term
| Central components of the ANS |
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Definition
Main control centres: hypothalamus and midbrain
Direct control of symp & parasymp divisions
Cerebral cortex can influence but not command the control centres (e.g. emotional status causes blushing (cutaneous vasodilation))
Descending fibres to the brain stem and spinal cord |
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Term
| Peripheral components of the ANS |
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Definition
Brain stem & sacral cord level: outflow of parasymp innervation
Thoraco-lumbar cord level: outflow of symp innervation |
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Term
|
Definition
Long pre-synaptic fibers
Acetylcholine neurotransmitter to
short post-synaptic fibres to
ACH neurotransmitters to
Cardiac muscle, Smooth muscle, and Glands |
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Term
|
Definition
Short pre-synaptic fibers to
ACh neurotransmitters to
long post-synaptic fibers to either
ACh neuromtransmitters to Sweat glands
OR
Norepinephrine neurotransmitters to
Cardiac muscle, Smooth muscle, Glands |
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Term
| Sympathetic System Trunks |
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Definition
Vasosympathetic trunk (to head/neck) from T1-5/7
Sympathetic trunk (Branches: Thoracic & lumbar splanchnic nerves) to T1-L2/4 |
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Term
|
Definition
Oculomotor nerve
Origin: Midbrain
Ganglion: close to eye
Target organ: Ciliary muscles (regulate lens curvature)and Muscles of iris (pupil constriction) |
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Term
|
Definition
Facial Nerve
Orgin: brainstem)
Ganglions:
Pterygopalatine (sphenopalatine)
Target organ: Lacrimal, nasal & palatine glands (secretion, vasodilation)
AND
Sublingual & mandibular
Target organ: Sublingual & mandibular glands (secretion, vasodilation) |
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Term
|
Definition
Glossopharyngeal Nerve
Origin: of origin: brainstem
Ganglion: Otic
Target organ: Parotid & orbital salivary glands (secretion, vasodilation) |
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Term
|
Definition
Vagus Nerve
Origin: brainstem
Ganglion: Terminal (intramural)
Target organ: parasympathetic supply to neck, thorax and abdomen, Majority of body viscera (cervical, thoracic, abdominal)
Response: Many, e.g. heart rate, peristalsis, sweating, larynx opening |
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Term
|
Definition
Pre-synaptic fibres: Axons travel in pelvic nerves (located lateral wall of rectum)
Synapse: terminal ganglia (near the bladder, rectum and sexual organs)
Post-synaptic fibres: distribution to the pelvic viscera, lower intestinal cavity and reproductive organs |
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Term
Autonomic/Symp Innervation of the Eye
Function |
|
Definition
Supplies the smooth muscle of the orbit & the iris dilators
- Protrusion of the eyeball
- Widening of the palpebral fissure
- Third eyelid retraction
- Dilation of pupils |
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|
Term
Autonomic/Symp Innervation of the Eye
Neurons |
|
Definition
First order from brain
Second order: spinal cord segements T1-3, in vasosympathetic trunk
Third order: synapse in cranial cervical ganglion, medial to the tympanic bulla |
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Term
|
Definition
Loss of Sympathetic Input:
Pupillary constriction (miosis)
Prolapse of the third eyelid
Narrowing of the palpebral fissure
Enophthalmos (sinking of the eye)
Underlying disease e.g. disc herniation (neck) or middle ear infection (otitis) |
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Term
| Pupillary Light Reflex (PLR) |
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Definition
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Term
|
Definition
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Term
|
Definition
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Term
| Symp Innervation of Urinary Tract |
|
Definition
Predominant in storage phase
Hypogastric nerve (L1-4 in dogs, L2-5 in cats)
Relaxes the detrusor muscle in the wall of the bladder
Contraction of the smooth muscle of the bladder neck / internal urethral sphincter |
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Term
| Parasymp Innervation of Urinary Tract |
|
Definition
Predominant in voiding phase
Pelvic nerve (S1-3)
Contraction of detrusor muscle of bladder wall
Also supplies urogenital organs, rectum and descending colon |
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Term
| Somatic Innervation of the Urinary Tract |
|
Definition
Pudendal nerve (S1-3)
Contraction of the striated sphincter muscles for urinary retention
Also innervates the anal sphincter (perineal reflex!) |
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Term
|
Definition
Equine Grass Sickness
Debilitating and frequently fatal disease
Impaired activity of gut due to ANS damage
Cause still unknown, Clostridium botulinum type C may be involved
April and July |
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Term
| Three main presentations of Equine Dysautonomia |
|
Definition
Acute – severe and sudden onset with 100% mortality within 48 hours.
Sub-acute – milder clinical signs but most usually die within 7 days.
Chronic – Slower onset presenting with rapid weight loss. Some will survive. |
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Term
| Clinical Signs of Acute and Sub-acute Equine Dysautonomia |
|
Definition
Depression
Ileus
Tachycardia
Salivation
Gastric reflux
Fasciculation
Ptosis
Sweating
Dysphagia
Colic
impaction |
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Term
| Clinical Signs of Chronic Equine Dysautonomia |
|
Definition
Rapid and severe weight loss
Rhinitis sicca
Ptosis
Tachycardia
Fasciculation
Patchy sweating
Inappetance
Dysphagia |
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Term
|
Definition
Key Gaskell syndrome
Widespread dysfuntion of the ANS
All breeds/ages susceptible but commonly in younger cats
Aetiology unknown
Definitive diagnosis relies on histopathology
Radiography, Schirmer teat test and pharmacological testing may aid diagnosis
Treatment is purely supportive
Prognosis is guarded |
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Term
| Clinical signs of Feline Dysautonomia |
|
Definition
Depression
Anorexia
Bilateral pupil dilation non-responsive to light
Third eyelid protrusion and ptosis
Decreased tear and saliva production
Megaoesophagus
Bradycadia
Faecal and urinary incontinence |
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