A short and easy presentation on autonomic nervous system. Do let me know if any topic you want to learn in easy way.

1. AUTONOMIC NERVOUS
SYSTEM
By - NAMITA KAUSHIK
MPT (NEUROLOGY)
Certified in PT Management in SCI (ISCOS)

4. AUTONOMIC NERVOUS
SYSTEM
•
•
Control the internal environment of the body.
Provides a fine discrete control over the
functions of many organs and tissues, including
heart muscle, smooth muscle, and the exocrine
glands.

5. AFFERENT
NEURON
EFFERENT
NEURONCONNECTOR NEURON
The afferent impulses
originate in visceral
receptors
and travel via afferent
pathways to the
central nervous
system.
Impulses are
integrated through
connector neurons at
different levels
via efferent
pathways to visceral
effector organs

6. 



The efferent pathways of the autonomic system are
made up of preganglionic and postganglionic neurons.
The cell bodies of the preganglionic neurons are situated
in the lateral gray column of the spinal cord and in the
motor nuclei of the 3rd, 7th, 9th, and 10th cranial nerves.
The axons of these cell bodies synapse on the cell
bodies of the postganglionic neurons that are collected
together to form ganglia outside the central nervous
system.
Large collections of afferent and efferent fibers and their
associated ganglia form autonomic plexuses in the
thorax, abdomen, and pelvis.
Visceral receptors include chemoreceptors,
baroreceptors, and osmoreceptors.

9. SYMPATHETIC




Thoracolumbar or
adrenergic system
Fight, fright and flight
response
Larger of the two parts of
the autonomic system
Innervating the heart and
lungs, the muscle in the
walls of many blood vessels,
the hair follicles and the
sweat glands, and many
abdominopelvic viscera.

13. The lateral gray columns (horns) of the spinal cord from the T1
segment to the S2 segment (sometimes third lumbar segment)
possess the cell bodies of the sympathetic connector neurons.
The myelinated axons of these cells leave the cord in the
anterior nerve roots and pass via the white rami communicantes
to
the paravertebral ganglia of the sympathetic trunk.

14. Paravertebral
ganglia
Smooth muscles in
blood vessel walls,
Sweat glands,
Arrector muscles of
hairs of skin
Cervical spinal nerves,
Lumbar, sacral and
coccygeal spinal
nerves
Greater splanchnic,
lesser splanchnic,
least splanchnic
nerve,

15. Greater splanchnic
nerve
•
•
•
•
5th – 9th ganglia
It descends obliquely on the sides of
bodies of thoracic vertebrae.
Pierces the crus of diaphragm
Synapse with excitor cells in ganglia of the
celiac plexus, the renal plexus and
suprarenal medulla
A few preganglionic fibers travelling in the greater splanchnic nerves, end
directly on the cells of the suprarenal medulla

16. Lesser splanchnic
nerve
•
•
•
10th – 11th thoracic ganglia
Descends with greater splanchnic nerve and pierces
the diaphragm
And join excitor cells in ganglia in lower part of
celiac plexus
Lowest splanchnic
nerve
•
•
•
When present arises from 12th thoracic ganglion
Pierces diaphragm
Synapse with excitor neurons in ganglia of renal plexus

19. Sympathetic Trunks
•In the neck, each trunk has 3 ganglia;
in the thorax, 11 or 12;
in the lumbar region, 4 or 5;
in the pelvis, 4 or 5.
•Two ganglionated nerve trunks that extend the whole
length of the vertebral column
•
•
•
•
•
In the neck , the trunks lie anterior to the
transverse processes of the cervical vertebrae;
in the thorax, they are anterior to the heads of
the ribs or lie on the sides of the vertebral bodies;
in the abdomen, they are anterolateral to the
sides of the bodies of the lumbar vertebrae; and
in the pelvis, they are anterior to the sacrum.
Below, the two trunks end by joining
together to form a single ganglion, the ganglion
impar.

20. PARASYMPATHETIC


The activities of the parasympathetic part of the
autonomic system are directed toward conserving
and restoring energy.
The heart rate is slowed, pupils are constricted,
peristalsis and glandular activity is increased,
sphincters are opened, and the bladder wall is
contracted.

21. Connector nerve cells
Cranial sacral
1.
2.
3.
4.
Brainstem
Occulomotor - Edinger-
Westphal nucleus
Facial - superior salivatory
nucleus and lacrimatory
nucleus
Glossopharyngeal- inferior
salivatory nucleus
Vagus - dorsal nucleus of
the vagus
S2-S4 segments of the spinal
cord.

22. Sacral outflow



Myelinated axons leave tha spinal cord in the anterior
nerve root of corresponding spinal nerve
Then they leave sacral nerve and form the pelvic
splanchnic nerve.
Pelvic splanchnic nerve synapse in ganglia in
hyposgastric plexus.

23. Ganglia and plexus
Ganglia Plexus




ciliary,
pterygopalatine,
submandibular,
otic




cardiac plexus,
Pulmonary plexus,
myenteric plexus (Auerbach
plexus),
mucosal plexus (Meissner
plexus)
Myenteric and mucosal plexuses are
associated with gastro intestinal tract.

26. Autonomic ganglia




Collection of multipolar neurons together with
capsular or satellite cells and a connective tissue
capsule.
Site where preganglionic nerve fibers synapse on
postganglionic neurons.
Preganglionic fibers are myelinated, small,and
relatively slow conducting b fibers.
Postganglionic fibers are nonmyelinated, smaller and
slower conducting c fibers.

27. SIF Cells





These are small intensely flourescent cells.
They are present inside autonomic ganglia.
In some ganglia these cells receive preganglionic
cholinergic fibers and may modulate ganglionic
transmission.
In others, they receive collateral branches and may
serve some integrative function.
Many SIF cells contain dopamine, which is thought to
be their transmitter.

28. Preganglionic
neurons
Postganglionic
neuronsAch

29. Ach
receptors
nicotinic muscarinic
Fast
EPSP
Slow EPSP Slow IPSP

30. Ganglion stimulating agent Ganglion blocking agent



Nicotine
Lobeline
dimethylphenylpiperazinium


Depolarizing – nicotine
Non-depolarizing /
competing –
hexamethonium,
tetraethylammonium

31. Post ganglionic transmitters
Parasympathetic




Acetylcholine
Binds to muscarinic
receptors
acetylcholinestrase
Acetic acid + choline
Blocking agent
atropine

32. Sympathetic postganglionic
Ach
Sweat glands
Blood vessels in
skeletal muscles
Muscarinic
receptors
Nor
epinephrine
Excitatory
functions
Inhibitory
functions
Alpha
receptors
Beta
receptors
Blocking agent
atropine
Blocking agent
propranolol
Blocking agent
Phenoxybenzamine
Reserpine

33. Other postganglionic
transmitters



Adenosine triphosphate (ATP)
Neuropeptide Y
Substance P
They have their own specific receptors and their function is to
modulate the effect of primary transmitter.

34. Higher control of ANS


Hypothalamus –
Anterior region for parasympathetic responses
Posterior region for sympathetic responses.
lower brainstem centers – vasopressor, vasodilator,
cardioaccelerator, cardiodecelerator and respiratory
centers found in reticular formation through
descending pathways.

35. DIFFERENCE
SYMPATHETIC PARASYMPATHETIC





Thoracic outflow
Prepares body for emergency
Paravetebral and prevertebral
ganglia
Postganglionic fibers long
and non-myelinated
Widespread due to many
postganglionic fibers and
liberation of epinephrine and
nor epinephrine from
suprarenal medulla





Craniosacral outflow
Conserves and restores
energy
Small ganglia close to the
viscera or ganglion cells in
plexuses
Postganglionic fibres short
and non-myelinated
Discrete action with few
postganglionic fibers

43. Tests of autonomic cardiovascular reflexes
Valsalva manoeuvre
Active standing (orthostatic test)
Head-up tilt test
Baroreflex sensitivity testing
Deep breathing
Isometric handgrip test
Cold pressor test
Mental arithmetic

44. Testing of sudomotor function
Thermoregulatory sweat test
Sympathetic skin response (SSR)
QSART (Quantitative Sudomotor Axon Reflex Test)

45. THANK
YOU