AUTONOMIC NERVOUS SYSTEM

Judit Rosta

9 18 2019

Topics Nr. 19-20.

Evening Seminar Notes-Phys

ANATOMIC:

for the sympathetic system and the allied

nervous system of the cranial and sacral

nerves and for the local

nervous system of the gut .”

Sir John Newport Langley, 1898

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”…I propose the term

‚autonomic' nervous system

FUNCTIONAL:

„system of motor nerve cells to ‚involuntary’ structures” Gaskell, 1916

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What divisions of the nervous system are parts of the

parasympathetic nervous system classified as?

A. The somatic nervous system

B. The autonomic nervous system

C. The peripheral nervous system

D. Both B and C

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What divisions of the nervous system are parts of the

parasympathetic nervous system classified as?

A. The somatic nervous system

B. The autonomic nervous system

C. The peripheral nervous system

D. Both B and C

controls bodily functions that are performed unconsciously

not found in the brain or spinal cord

controls voluntary movements

„ ‚Sympathy’ : as cooperation and coordination of organs”

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Which autonomic superpower would you like to

have?

• The most quick fight or flight response in the world

• A total vegetative-hormonal harmony

• Gastrointestinal homeostasis ‚forever’

• Stabile body temperature independently from environment

cardiovascular, gastrointestinal

and thermal homeostasis

organization of stress responses

Maintain Vegetative Functions

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A. It solely controls the actions of sleeping and digesting.

B. It controls activities that take place when the body is at rest

and not deciding whether to face an opponent or run from it.

C. It increases the heart rate and activates the adrenal glands,

which allow the body to digest more efficiently.

D. It begins immediately after eating and ends immediately after

resting.

Why is the parasympathetic nervous system

called the “rest and digest” system?

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A. It solely controls the actions of sleeping and digesting.

B. It controls activities that take place when the body is at rest

and not deciding whether to face an opponent or run from it.

C. It increases the heart rate and activates the adrenal glands,

which allow the body to digest more efficiently.

D. It begins immediately after eating and ends immediately after

resting.

Why is the parasympathetic nervous system

called the “rest and digest” system?

SY

PARASY

PARASY

AND THE ‚PARA’SYMPATHETIC :

CRANIO-SACRAL DIVISION

(flank on both sides)

THE SYMPATHETIC TRUNK:

PARAVERTEBRAL CHAIN

Thoracolumbar origin

How can we distuinguish between

sympathetic and parasympathetic autonomic

nerves?

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constricts sphincters

Release of glucagonGlucose levels up

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nicotinic Ach-receptor

AUTONOMIC GANGLIA

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Can you overdose?

• Nicotine stimulates the postganglionic

neurons of both the sympathetic and

parasympathetic divisions!

• Different effects according to doses

(Agonist/Antagonist)

• The action of nicotine on acetylcholine

receptors of the neuromuscular synapse is

much less important than that on ganglia of

the autonomic nervous system

lethal dose: 500-1000 mg

2 mg/cigarette

it wouldtake smokingover

100 cigarettesin a shorttime

periodto ingest a lethaldose

tobaccoleavesthroughskin

canproducehighdoses!

• source of innervation

• the activity of the nerves

• the effect of nervous activation

• neurotransmitter using which receptor

• peripheral or central control

Autonomic control of a target organ

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o smooth muscle

o cardiac muscle

o glands

How to learn…

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How does look like the autonomic innervation?

Choose the typical presynaptic arrangement of an autonomicneuron!

Common presynaptic arrangements

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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 act on their own receptors!

Ach+ATP

NE+NPY

• source of innervation

• the activity of the nerves

• the effect of nervous activation

• neurotransmitter using which receptor

• peripheral or central control

Autonomic control of a target organ

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sympathetic vs. parasympathetic

Dual Innervation

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Dual innervation -Antagonistic effects

„each tissue supplied by two sets of fibers with opposite

characters”

lacrimal gland acini ciliary muscle musc. sphincter pupillae Bronchial smooth muscle

PSYSY adrenal medulla arrector pili muscles sweat glands most blood vessels musc.dilatator

pupillae ventricle of the heart

Exemptions of Dual Innervation

• source of innervation

• the activity of the nerves

• the effect of nervous activation

• neurotransmitter using which receptor

• peripheral or central control

Autonomic control of a target organ

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tonic or phasic

Tonic Activity of Sympathetic Nerves Vagal Tone

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

at rest increased effectdecreased effect

Pattern of action potentials rate of an autonomic fiber exerts tonic activity

Topic Nr.19.Tonic Activity of Sympathetic Nerves Vagal Tone

• source of innervation

• the activity of the nerves

• the effect of nervous activation

• neurotransmitter using which receptor

• peripheral or central control

Autonomic control of a target organ

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Contraction vs. relaxation

inhibition/stimulation of secretion

+/- cardiac effects

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SY VASOMOTOR TONE

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

BRONCHIWITH

blood-streamsmooth muscle

mucus secretioncontraction

dilation

secretorygland

The bronchi don’t have sympathetic

innervation but adrenergic receptors are

present which are activated by the

circulating catecholamines.

PSY BRONCHOMOTOR TONE

PSY: Vagal nerve Bronchoconstriction, secretion

SY: Bronchodilation, secretion↓

Circulating EPINEPHRINE!

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HEARTWITH DUAL INNERVATIONBUT VENTRICLE !

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

Heart rate: 72 beats/min

PSY TONE

+

+

-

SY

INNERVATION OF THE

PUPIL

T1

ATROPINE

PSY MYOSISSY MYDRIASIS

Pupillary Light

Reflex PSY

two distinctmuscles areinnervated

Horner’s (triad)- ipsilateral loss innervation of:

1. Miosis - pipullary dilator muscle

2. Ptosis - tarsalis muscle

3. Enopthalmus - orbitalis muscle

4. (Anhydrosis) - facial sweat glands

5. (Flush) - facial skin arterioles

Pancoast tumor

The loss of sympathetic

Horner’s syndrome Lesion of the superiorcervical ganglion(tumor, trauma).

• source of innervation

• the activity of the nerves

• the effect of nervous activation

• neurotransmitter using which receptor

• peripheral or central control

Autonomic control of a target organ

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• muscarinic cholinergic

• a (1,2) or b (1, 2, 3) adrenergic

• „NANC” mechanism

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

Cotransmitter: NE + NPY, ATP

NOTICE!

Synthetisation-vesicles

NE-terminals, E-adrenal med.

Metabolism by: COMT, MAO

Neuronal reuptake

Autoreceptor

blocked by

cocaine !

CATECHOLAMINES

9/19/2018 Evening Seminar Notes-Physpinterest.com

Description of a Case:

A 5-year-old boy, „red face”, disoriented,

distracted manner, amnesia, hallucination

blood pressure 130/89 Hgmm,

pulse 140/min

temperature 39.6

pupils Dilated

No Sy action

Psy dropout

Central effect

Psy dropout

Course:

Ach up

(AchE inhibitor)

Physostigmine

History: Ingestion of black seeds of a plant located near the house

Diagnosis:

Antimuscarinic

intoxication

More adverse effects:

• inhibits the secretion of saliva

• produces bronchodilation

• urinary retention

ATROPINE

9/19/2018 Evening Seminar Notes-Physpinterest.com

Description of a Case:

A 5-year-old boy, „red face”, disoriented,

distracted manner, amnesia, hallucination

blood pressure 130/89 Hgmm,

pulse 140/min

temperature 39.6

pupils Dilated

No Sy action

Psy dropout

Central effect

Psy dropout

Course:

Ach up

(AchE inhibitor)

Physostigmine

History: Ingestion of black seeds of a plant located near the house

Diagnosis:

Antimuscarinic

intoxication

More adverse effects:

• inhibits the secretion of saliva

• produces bronchodilation

• urinary retention

ATROPINE

M1,3 a1

Gq/11

PLC

Ca++ ↑

• Release

• Muscle contraction

Gs

b1-3

AC

cAMP ↑

• Ion channels phosphoril.

• Muscle relaxationM2,4

Gi/o

AC

cAMP ↓

• Inhibitory action

a2

M1,2,3b2

• which neurotransmitter using which receptor

Autonomic control of a target organ

Respir Res. 2006; 7(1): 73.

increased smooth muscle contraction (bronchoconstrion)

mucosawall of the bronchus

lumensmooth muscle

increased secretion of the glands in the airways

4. b2-agonists

1. Atropin

3. a1-agonists

2. MAO-inhibitors

5. AchE-inhibitors

Which of the followings can be used?Provoke dilatation of the airways

DECREASE PSY TONE

or INCREASE SY EFFECT

Bronchial Asthma THERAPY(chronic inflammation of the airway)

Respir Res. 2006; 7(1): 73.

increased smooth muscle contraction (bronchoconstrion)

mucosawall of the bronchus

lumensmooth muscle

increased secretion of the glands in the airways

4. b2-agonists

1. Atropin

3. a1-agonists

2. MAO-inhibitors

5. AchE-inhibitors

Which of the followings can be used?

Anticholinergic effect

direct smooth muscle relaxation

Provoke dilatation of the airways

DECREASE PSY TONE

or INCREASE SY EFFECT

Bronchial Asthma THERAPY(chronic inflammation of the airway)

How can we distuinguish between

sympathetic and parasympathetic autonomic

nerves?

„rest and digest” vs.

„flight or fight”

Functionally

Neurochemically

adrenergic vs. cholinergic

Thoraco-lumbal

vs.

Cranio-sacral

Anatomically

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What happens when both a and b adrenergic receptors are expressed by the same tissue?

What may be the significance of different potency of a transmitters toward distinct receptors?

At low concentration of Adrenaline b2 effect predominates vasodilation(anticipation)At high plasma concentration of Adrenalinea1 effect predominates vasoconstriction

Adrenaline (Epinephrine) is far more potent beta-adrenoceptor agonistthan NA. Importance of circulating A in arrythmias and bronchi

anticipation

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1.M-AchR agonist MUSCARINE

2.M-AchR- antagonist Atropine

3.sympathomimetics like MAO inhibitors

Autonomic control of a target organ

Choose, which of the followings can be used

stimulate the urinary bladder following

surgery:

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spinal reflexes

o erection

o defecation

o urination

Spinal shock- areflexia- loss

of central excitatory impulses

e.g. “presympathetic” sympathetic

inputs originate in the brainstem-

cardiovascular targets

Integrative Function of the Spinal

Cord BUT Supraspinal Stimuli

Vegetative Reflexes

Vago-vagal reflex

Efferent response through modulation of Psy tone