Autonomic function Flashcards
Features of the autonomic nervous system
ANS neurons -> post ganglionic
Sympathetic NS (fight or flight)
^ Stress
Eyes - dilate pupil
Salivary glands - inhibit salvation (dry mouth)
Heart - accelerate heart beat
Lungs - dilate bronchi (increase breath in)
Stomach - infinite digestion
Liver - stimulates glucose release
Kidneys - stimulate epinephrine and norepinephrine release
Intestines - inhibit peristalsis and secretion
Bladder - relaxes bladder
Parasympathetic NS (rest and digest)
^ Peace
Eyes - constrict pupil
Salivary glands - stimulates salvation
Heart - slow heartbeat
Lungs - constrict bronchi
Stomach - stimulates digestion
Liver- stimulates bile release
Intestines - stimulate peristalsis and secretion
Bladder - contacts bladder
What are the differences and roles of the autonomic nervous system
Parasympathetic (pupil, heart)
- long preganglionic axons
- short post ganglionic axons
Targeted organs
- glands (ACh)
- smooth muscle (ACh)
- heart (ACh)
Sympathetic (sweat gland,pupil, BI vessels, heart)
- short preganglionic axons
- long post ganglionic axons
(Shorter preganglionic axon, to activate quicker in state of stress)
Targeted organ
- blood vessels (NA)
-heart (NA)
- sweat glands (ACh)
- adrenal medulla (NA/Adr)
What are the nerve differences between sympathetic and parasympathetic NS
Sympathetic nerves mainly constant of post-ganglionic, non myelinated fibres
Parasympathetic nerves mainly consist of preganglionic, myelinated fibres
All ganglia ACh mediated signaling via neuronal nicotinic receptors.
Types of autonomic dysfunction
- BP/HR
- Digestion
- Bladder/ Bowel
- Temperature
- Sexual
Autonomic control and BP
Increased sympathetic activity results in
- increased cardiac output
- increased total peripheral resistance
Therefore increased arterial blood pressure
500-1000ml of blood flow shifts to lower body upon standing.
Symptoms:
- collapse
- lightheadedness
- dizziness
- coat hanger pain
- exercise intolerance
-fatigue post mean or syncope following large meal
Triggers:
- worst in the morning
- worst upon heat exposure
- worst after eating a large meal or after exercise
Failure of sympathetic vasoconstrictor output leads to NOH
(Defined as: >20mmHg systolic and or >10mmHg diastolic decline in blood pressure within 3 mins of standing)
(Does not distinguish different autonomic disorders, nor extent of autonomic involvement)
Neurogenic orthostatic hypotension is only one of manifestation of orthostatic intolerance
Neurogenic -> PoTS -> OH post
OH Bed rest
Drugs
Severe, disabling, Benign,
Persistent —> Episodic,
LT management Intermittent
Autonomic dysfunction and gastrointestinal control
- constipation
- diarrhea
- nausea
- vomiting
- bloating
Genito-urinary dysfunction and autonomic dysfunction
- nocturia
- urinary urgency, incontinence, retention
- sexual dysfunction
Autonomic dysfunction and temperature control
- heat intolerance
- collapse triggered by warm environment
- lack of sweating
- increased sweating
Hypothalamus acts as thermostat, that makes thermoregulatory adjustments to deviations from temperate norm in the brain (37°c +/- 1)
- core temp is priority, Andy shell temperature shifts around the body to regulate core temperature, by redistributing blood volume)
Autonomic disorders and examples
Autonomic failure / Autonomic dysfunction
Generalised autonomic failure
- cardio (OH)
- Sudomotor (anhidrosis, heat intolerance)
- GI (constipation etc)
- urinary (Nocturia, urgency etc)
-Reproductive (ED)
-respiratory (stridor)
-Ocular (alacrima)
Why does it occur?
- autoimmune autonomic ganglionopathy
- autonomic neuropathy (post ganglionic, sympathetic neuron)
Classification and neurodegenerative disorders presenting with prominent autonomic failure
- Autonomic failure with brain involvement
Frequently associated with severe autonomic failure
- MSA
- PD
- DLB
Commonly associated with moderate autonomic failure
- SCA
- PSP
- FXTAS
- Autonomic failure with spinal cord involvement
- Spinal cord injury
- Multiple sclerosis
- Transverse M
- Tumors
Autonomic Dysreflexia (life dysreflexia)
- pupil dilation, watery eye
- neck/face flushing
- sweating
- elevated bp, at least 20mmHg from baseline and bradycardia
- cold peripheries, piloerections
- contraction of bladder and large bowel
- Autonomic neuropathies
- AAG
- GBS
- Paraneoplastic
- toxic
(^ acute/ subacute)
- diabetes
- amyloid
- Sjogren
(^ chronic)
AAG ( autoimmune autonomic neuropathy)
Features
Pathology
- Acute or subacute onset
- gnAChR decrease the strength of synaptic transmission at the autonomic ganglia
- settings levels of gnAChR AB correlated with the severity of symptoms and severity of autonomic dysfunction on objective testing
- immunomodulatory treatment can be effective in both seropositive and seronegative AAG
What are the types of Autonomic neuropathies
Diabetic autonomic neuropathy
(Most frequent)
Amyloidosis
Immune mediated A N
Hereditary A N
Infection associated A N
Toxic A N
Diabetic autonomic neuropathy, what is it and what are the autonomic symptoms ?
Prevalence of autonomic dysfunction in diabetes mellitus increases with:
- disease dystonia
- patient age
- poor glycemic
- presence of; microvascular complications, hperlipidemia, hypertension (type 2)
- Cardiac autonomic neuropathy
- Widespread diabetic autonomic neuropathy
- Treatment induced painful autonomic neuropathy
- Transient autonomic dysfunction
- Gastrointestinal dysfunction
- Neurogenic bladder
- Erectile dysfunction
- Compensatory hyperhidrosis
What are the different types of amyloidosis
1.Primary Amyloidosis (AL immunoglobulin light chain associated)
2.Hereditary Amyloidosis ( familial amyloid poltneuropathy; FAP)
- Familial amyloid polyneuropathy
1) HR variability in time and frequency
2) abnormalities in tests of adrenergic function, inc head up tilt
- painful sensorimotor neuropathy
- carpal tunnel syndrome
-enteric neuropathy, nephropathy, cardiomyopathy
3) disorders of malfunction of ANS
- pots
-reflex syncope
4) paroxysmal vasomotor/ sudomotor disorders
- hyperhidrosis
- erytromelalgia
5) genetic disorders of autonomic neurotransmisson
