Upload
vuminh
View
217
Download
0
Embed Size (px)
Citation preview
AUTONOMIC NERVOUS SYSTEM
THE AUTONOMIC NERVOUS SYSTEM
Judit Rosta
TOPICS Nr. 19-20.
9/19/2018 Evening Seminar Notes-Phys
AUTONOMIC NERVOUS SYSTEM
…“I propose the term 'autonomic' nervous
system for the sympathetic system and the
allied nervous system of the cranial and
sacral nerves and for the local nervous
system of the gut .”…
(John Newport Langley, 1898)
9/19/2018 Evening Seminar Notes-Phys
AUTONOMIC NERVOUS SYSTEM
Autonomic Peripheral
Efferents
maintain cardiovascular, gastrointestinal
and thermal homeostasis
and organization of stress responses
Autonomic(„automatic control”)
Vegetative(function)
9/19/2018 Evening Seminar Notes-Phys
„ …System of motor nerve cells
to ‚involuntary’ structures”: (Gaskell, 1916)
AUTONOMIC NERVOUS SYSTEM
9/19/2018 Evening Seminar Notes-Phys
Menitmeter
AUTONOMIC NERVOUS SYSTEM
• source of innervation (sympathetic-parasymp.,dual-not dual)
• the activity of the nerves (tonic or phasic)
• the effect of nervous activation (contraction-relaxation,
stimulating/inhibiting secretion, +/- cardiac effects etc.)
• neurotransmitter using which receptor (muscarinic cholinergic, alpha
(1 or 2) or beta (1, 2 or 3) adrenergic, perhaps „NANC” mechanism)
• peripheral or central nervous structures control nervous activity-
vegetative reflexes
Autonomic control of a target organ:
(smooth muscle, cardiac muscle, glands)
9/19/2018 Evening Seminar Notes-Phys
AUTONOMIC NERVOUS SYSTEM
„ ‚Sympathy’ ?: as cooperation and coordination of organs”
SY
PARASY
PARASY
AND THE ‚PARA’SYMPATHETIC :
CRANIO-SACRAL DIVISION
(flank on both sides)
„each tissue supplied by two sets of fibers with
opposite characters”
Dual innervation-Antagonistic effects
THE SYMPATHETIC TRUNK:
PARAVERTEBRAL CHAIN
Thoracolumbar origin
9/19/2018 Evening Seminar Notes-Phys
AUTONOMIC NERVOUS SYSTEM
SYMPATHETIC
PARASYMPATHETIC
9/19/2018 Evening Seminar Notes-Phys
NOTICE ! Structure (location of ganglia)Fiber type (myelinization)Neurotransmitters (Ach, NE,E)
AUTONOMIC NERVOUS SYSTEM
9/19/2018 Evening Seminar Notes-Phys
Menitmeter
How does look like the autonomic innervation?Choose the typical presynaptic arrangement of an autonomic neuron!
Common presynaptic arrangements:
AUTONOMIC NERVOUS SYSTEM
9/19/2018 Evening Seminar Notes-Phys
Burnstock (1988) Autonomic neural control mechanisms. With special reference to the airways. In: Kaliner, M.A., Barnes, P.J. (Eds.)
How does look like the autonomic innervation?
Network of varicose terminal axons containing norepinephrine in iris
((Falck, 1962)
VARICOSITY: contain the enzymes necessary to synthesize or degradetransmitters
Autonomic ground plexus
cotransmitters: Ach+ATP, Norepinephrine+NPY(act on their own receptors!)
AUTONOMIC NERVOUS SYSTEM
Cotransmitter: Ach + VIP, NO
Botulinum TOXIN
Physostigmin
ACETYLCHOLINE
Parasympathetic(and sudomotor sympathetic)
Notice!
Acetylcholinesterase (AchE)
Choline reuptake
Botulinum toxin blocking
AchE blocking-muscarinic
Atropine-antimuscarinic
ATROPINE
AUTONOMIC NERVOUS SYSTEM
Cotransmitter: NE + NPY, ATP
NOTICE!
Synthetisation-vesicles
NE-terminals, E-adrenal med.
Metabolism by: COMT, MAO
Neuronal reuptake
Autoreceptor
blocked by cocaine !
CATECHOLAMINES
AUTONOMIC NERVOUS SYSTEM
9/19/2018 Evening Seminar Notes-Phys
Adrenaline (Epinephrine) is far more potent beta-adrenoceptor agonistthan NA. Importance of circulating A in arrythmias and bronchi
+-
At low concentration of Adrenaline b2 effect
predominates vasodilation (anticipation)
At high plasma concentration of Adrenaline
a1 effect predominates vasoconstriction
SKELETAL MUSCLE ! BLOOD VESSELS
RECEPTORS
M1,2,3
LUNG
HEART
b2
AUTONOMIC NERVOUS SYSTEM
9/19/2018 Evening Seminar Notes-Phys
AUTONOMIC PHARMACOLOGY
-MIMETICS (+):
1. increase synthesis/release of NT
2. decrease degradation of NT
3. use receptor agonist
4. block synthesis of NT
5. block release of NT
6. use receptor antagonist
-LYTICS:
Antimuscarinic effect: M-AchRantagonist (Atropine)
Sympathomimetic e.g.: Amphetamineincreases NE synthesis and release
AUTONOMIC NERVOUS SYSTEM CURARE (-)
nAchR
ATROPINE
M-AchR
E: b>a
PROPRANOLOL (-)
a-AR
BOTULINUM TOXIN (-)
9/19/2018
PRAZOSIN (-)
COCAINE(+)
NICOTINE
nAchR
AU
TO
NO
MIC
PH
AR
MA
CO
LOG
Y
ISOPROTERENOL (+)
b-AR
AMPHETAMINE (+)
PHYSOSTIGMINE(AchE inhibitor)
nAchR
nAchR
nAchR
AUTONOMIC NERVOUS SYSTEM
9/19/2018 Evening Seminar Notes-Phys
constricts sphincters
Release of glucagonGlucose levels up
AUTONOMIC NERVOUS SYSTEM
Evening Seminar Notes-Phys
tonic activity of the autonomic nervous
system under resting condition
VEGETATIVE TONE
- psy tone in the heart
- sy tone in the arterioles
- psy tone in the bronchi
Predominance of a
division!
at rest increased effectdecreased effect
Pattern of action potentials rate of an autonomic fiber exerts tonic activity
return individually below
AUTONOMIC NERVOUS SYSTEM
How can we distuinguish between sympathetic and parasympathetic autonomic nerves? (1)
a) Functionally, based on whether the effects can be attributed to the to „rest and digest” or the „flightor fight” group of responses
b) Neurochemically, as the sympathetic nerves are all adrenergic and the parasympathetic nerves are all cholinergic
c) Anatomically, as the sympathetic nerves stem from the thoracolumbal spinal cord segments, and the parasympathetics stem from the brainstem as well as from the sacral spinal cord segments
9/19/2018 Evening Seminar Notes-Phys
Mentimeter
AUTONOMIC NERVOUS SYSTEM
9/19/2018 Evening Seminar Notes-Phys
Mentimeter
Choose, which of the followings can be used stimulate
the urinary bladder following surgery:
1. M-AchR agonist MUSCARINE
2. 2.M-AchR- antagonist Atropine
3. 3. sympathomimetics like MAO inhibitors
AUTONOMIC NERVOUS SYSTEMCASE STUDY ANALYSIS
9/19/2018 Evening Seminar Notes-Phys
Case:
Antecedent: 10-years old boy, „red face”, disoriented, distracted
manner, hot temperature
Basic parameters: blood pressure 170/110 Hgmm,
pulse 144/min !
temperature 39.6 !
Flushed, hot, dry skin
Dilated pupils! (mydriasis), cycloplegia (no accomodation)
Neurological symptoms: amnesia, hallucination
AUTONOMIC NERVOUS SYSTEM
9/19/2018 Evening Seminar Notes-Phys
CASE STUDY ANALYSIS
SY provocation and/or Psy dropout ??
SYMPTOMS COMMENT
CONSIDER!
-Compare heart effects and vasoactive effects
-Source of ciliary muscles innervation (accomodation reflex)
-Sudomotor effects (dry skin)
dilated pupils
AUTONOMIC NERVOUS SYSTEM
Symptoms Comment:
BP:170/110 Hgmm little effect on blood pressure (not so much muscarinergic
vasodilation what can be suspended)
HR: 144/min speeds up the heart rate and increases conduction velocity= PSY
tone decreased
Flushed, hot, dry
skin
inhibited the activity of sweat glands
T: 39.6 sweating sufficiently depressed and this elevated the body
temperature
Dilated pupils
(mydriasis)
cholinergically innervated sphincter muscles of the iris relaxed
Cycloplegia
(no accomodation)
accommodative ciliary muscle of the lens is blocked
Amnesia,
Hallucinationrestlessness
symptoms can be explained by loss of muscarinic effects9/19/2018 Evening Seminar Notes-Phys
CASE STUDY ANALYSIS
AUTONOMIC NERVOUS SYSTEM
Diagnosis: Atropine Overdose
ANTIMUSCARINIC INTOXICATION
Course: Small doses of Physostigmine slowly intravenously
administered
Within 6 hours normal vital signs. The remainder of the
stay was uneventful.
9/19/2018 Evening Seminar Notes-Phys
Case History: Ingestion of black
seeds of a plant
located near the house
CASE STUDY ANALYSIS
AUTONOMIC NERVOUS SYSTEM
pinterest.com
Physostigmine has side effects on skeletal muscles (Ach up)
9/19/2018 Evening Seminar Notes-Phys
Atropine effect: M-AchR antagonist
Course: PSY mimetic (Physostigmine)
Overdose: ANTIMUSCARINIC INTOXICATION
ATROPINE
AUTONOMIC NERVOUS SYSTEM
Atropine and Antimuscarinic Alkaloids:
9/19/2018 Evening Seminar Notes-Phys
• Atropa Belladonna: medicine, cosmetic and poison
the devil’ breath aka SCOPALAMINE- an alkaloid of belladonna, is helpful in treating motion sickness
Belladonna has a long history of medicinal applications in healthcare
Scopalamine: „…criminals in Colombia and Ecuador use the
drug, which is said to remove a person’s free will…”
(TheGuardian)
The famous poison
of Roman
Emperors’ wives
• Datura stramonium: hallucinogen- fatally toxic
Extracurrical
AUTONOMIC NERVOUS SYSTEM
More adverse effect
Gastrointestinal tract decreased bowel sounds, reduction of salivary secretion
Respiratory tract inhibits the secretion of nose, mouth, pharynx and
bronchi
produces bronchodilation
Urinary retention Urinary sphincter contraction
Therapeutic Uses of Atropine
PREANAESTHETIC MEDICATION Can suppress bronchiolar secretions and reduce the risk
of airway obstruction
increase the heart beat when anaesthetic drug is going
to be used
ANTIDIARRHEAL DRUG in the treatment of irritable bowel movement
OPTHALMOLOGICAL USES; against peptic ulcer; dries up breast milk…
Extracurrical
9/19/2018 Evening Seminar Notes-Phys
ATROPINE
AUTONOMIC NERVOUS SYSTEM
Exemptions of Dual Innervation
adrenal medulla
arrector pili muscles
sweat glands
most blood vessels
musc.dilatator pupillae
ventricle of the heart
lacrimal gland acini
ciliary muscle
musc. sphincter pupillae
Bronchial smooth muscle
9/19/2018 Evening Seminar Notes-Phys
PSYSY
AUTONOMIC NERVOUS SYSTEM
9/19/2018 Evening Seminar Notes-Phys
HEART
The endogenous frequency of the pacemaker cells: 100 AP/min
The individual variation of the heart rate at rest is based mainly on the difference in the psy tone at rest
chronotropic effect:(incerased frequency of AP generation)
dromotropic effect:(increased speed of AP propagation)
heart rate: 72 beats/min!!!!!!Psy tone
+
+-
-
Predominance of PSY
AUTONOMIC NERVOUS SYSTEM
INNERVATION OF THE PUPIL
T1
Nucl.Edinger-
Westphal
(oculomotor nucl.)
NOTICE!
Pupillary Light Reflex
(PSY REFLEX!)
ATROPINE
PSY: myosisSY: mydriasis
9/19/2018 Evening Seminar Notes-Phys
SY
PSY
The two distinctmuscles
AUTONOMIC NERVOUS SYSTEM
Horner’s syndrome
„The loss of sympathetic”
Lesion of the superior cervical ganglion (tumor, trauma).Sympthoms: Horner’s (triad)- ipsilateral
Lost innervation of:1. Miosis - pipullary dilator muscle2. Ptosis - tarsalis muscle3. Enopthalmus - orbitalis muscle4. (Anhydrosis) - facial sweat glands5. (Flush) - facial skin arterioles
Pancoast tumor
AUTONOMIC NERVOUS SYSTEM
9/19/2018 Evening Seminar Notes-Phys
Sympathetic VASOMOTOR TONE
Serum Ach caused endothelium-derived NO-
dependent relaxation
keeps vasculatura and arterioles partially
constricted and this maintains blood pressure
(regulating amount of blood flow into the
capillaries)
carry out their function through the change of their diameters
a1
BLOOD VESSELS WITHOUT DUAL INNERVATION
AUTONOMIC NERVOUS SYSTEM
Bronchi
PSY
Vagal nerve
Bronchoconstriction, secretion (M1)
SY
Bronchodilation, secretion↓ (β2)
- Circulating EPINEPHRINE
parasympatheticpreganglionar
sympatheticpostganglionar
blood-stream
smoothmuscle
mucus secretion
contractiondilation
secretorygland
The bronchi don’t have sympathetic innervation but adrenergic receptors are
present which are activated by the circulating catecholamines.
9/19/2018 Evening Seminar Notes-Phys
Parasympathetic BRONCHOMOTOR Tone
AUTONOMIC NERVOUS SYSTEM
9/19/2018 Evening Seminar Notes-Phys
increased smooth muscle contraction (bronchoconstrion)
increased smooth muscle contraction (bronchoconstrion)
mucosawall of the bronchus
lumensmooth muscle
increased secretion of the glands in the
airways
THERAPY: Dilatation of the airways
increase of the sympathetic effect decrease of the parasympathetic effect
b2-agonist Atropin
Bronchodilatation
direct smooth muscle relaxation Anticholinergic effect
Respir Res. 2006; 7(1): 73.
Bronchial asthma:
chronic inflammation of the airway
AUTONOMIC NERVOUS SYSTEM
NICOTINE
9/19/2018 Evening Seminar Notes-Phys
Notice!
• Nicotine stimulates the postganglionic
neurons of both the sympathetic and
parasympathetic divisions!
• The action of nicotine on acetylcholine
receptors of the neuromuscular synapse is
much less important than that on ganglia of
the autonomic nervous system
• Different effects according to doses
(Agonist/Antgonist)
Nicotine lethal dose: 500-
1000 mg
Nicotine dosage in a traditional
cigarette: 2 mg
it would take smoking over 100
cigarettes in a short time period
to ingest a lethal dose
BUT: tobacco leaves through
skin can produce high doses
AUTONOMIC NERVOUS SYSTEM
9/19/2018 Evening Seminar Notes-Phys
Vegetative Functions: Integrative Function of the Spinal Cord
Micturition Reflex
• spinal reflexes: – erection
– defecation
– urination
The ‚VEGETATIVE REFLEX’
AUTONOMIC NERVOUS SYSTEM
9/19/2018 Evening Seminar Notes-Phys
Vegetative Functions:Supraspinal Stimuli- Brainstem control
• brainstem reflexes:e.g. touching cornea – lacrimation; salivation, swallowing, vomiting, coughing, sneezing
HYPOTHALAMUS
Thermoregulation:
Preoptic area
Peripheral thermoreceptors
Sympathetic vasomotor, sudomotor
Endocrine response: TRH,tiroxin synthesis
MEDULLA
Nucl. Tractus Solitarii
Vegetative efferents
Visceral afferents
e.g. vasomotor (RVLM), respiratory, coughing centre interneurons
Target organ
AUTONOMIC NERVOUS SYSTEM
9/19/2018 Evening Seminar Notes-Phys
Anticipation of exercise
Heart rate, blood pressure and respiratory
rate increased with anticipation
Vegetative stimulation correlates with activation
in certain structures in CNS
(etc. PAG, dorsal raphe nuclei) Limbic system, cortical areas
Vegetative Functions:Supraspinal Stimuli- Central Coordination
Spinal shock-areflexia- loss of central
excitatory impulses