This slide contains brief but easy discussion on autonomic nervous system,

1. Autonomic Nervous System
Dr. Zillur Rahman
Dr. Ashraful Islam
Dr. Azim Anwar
Dr. Al Amin
Resident in MD Cardiology,
BSMMU

2. INTRODUCTION OF
AUTONOMIC NERVOUS SYSTEM
Dr.Zillur Rahman

3. Central nervous system
(brain & spinal cord)
Peripheral nervous system
(Cranial & spinal nerves)
Afferent nerves
(from peripheral
tissues to CNS)
Efferent nerves (from
CNS to peripheral
tissues)
Somatic or
Voluntary
Autonomic or
Involuntary
Sympathetic
system
Enteric System
Parasympathetic
system

4. DIFFERENCE BETWEEN SOMATIC AND
AUTONOMIC NERVES
AUTONOMIC NERVES
• Supply everything except skeletal
muscles
• Ganglia are out side the cerebrospinal
axis
• Produces extensive nerve plexuses
• Efferent neurotransmitter  Ach ,NA
• Post ganglionic fibres are non
myelinated
• On interruption  incomplete
paralysis
SOMATIC NERVES
• Supplies skeletal muscles
• Ganglia are inside the cerebrospinal
axis. NO PERIPHERAL GANGLIA
• Does not produce extensive nerve
plexuses
• Efferent neurotransmitter  ACh
• Post ganglionic fibres are myelinated
• On interruption  complete paralysis

5. INTRODUCTION
• ANS control the internal environment of the body
• It is the ANS that provides a fine discrete control
over the functions of many organs and tissues
including heart muscle,smooth muscle and exocrine
gland
• It is distributed throughout the CNS and PNS
• The control exerted by ANS is extremely rapid and
widespread
• Majority of the activities of ANS donot impinge on
consciousness

6. History
• In 1921, Langley originally proposed the
generic term ‘autonomic nervous system’
• Langley noted the absence of
sensory(afferent) nerve cell bodies in
autonomic ganglia and defined ANS as purely
motor system
• Physiologist Walter Cannon argued that ANS is
specialized for ‘homeostasis’ or maintenance
of stability of internal environment.

7. COMPONENTS of ANS
• It has afferent,connector and efferent neurons
• The afferent impulse originate from visceral
receptors include
chemoreceptors,baroreceptors,osmoreceptors,pain
receptors
• Impulses travel via afferent pathways to the CNS
• In CNS intregration occurs through connector
neurons at different level
• Then leave via efferent pathways to visceral effector
organs

8. • The efferent pathways are made up of preganglionic
and postganglionic neurons
• The cell bodies of preganglionic neurons are
situated in the lateral gray column of spinal cord
and motor nuclei of 3,7,9,10 cranial nerves
• The axons of these cell bodies synapse on the cell
bodies of postganglionic neurons that are collected
together to form ganglia outside the CNS
• Large collections of afferent and efferent fibres with
their associated ganglia form autonomic plexuses in
thorax,abdomen and pelvis

9. Division
• The autonomic nervous system is divided into
two parts-
-the sympathetic system
-the parasympathetic system
• This division is made on the basis of
-differences in anatomy
-differences in the neurotransmitters
-differences in the physiologic effects.

10. Anatomy of
Autonomic Nervous System
Presented by Dr.Ashraful Islam

11. Sympathetic Part of the Autonomic
System
• larger of the two parts
• function is to prepare the body for an
emergency.
• consists of the efferent outflow from the
spinal cord, two ganglionated sympathetic
trunks, important branches, plexuses, and
regional ganglia.

12. Efferent fibres (sympathetic outflow)
• The lateral gray column of spinal cord from T1-L2
possess the cell bodies of sympathetic connector
neuron
• The myelinated axons of these cells leave the cord
in the anterior nerve roots and pass via the white
rami communicants to the paravertebral ganglia of
sympathetic trunk
• Then they are distributed as follows:

13. • They synapse with an excitor neuron in the ganglia
• The postganglionic nonmyelinated axons leave the
ganglion and pass to the thoracic spinal nerve as
gray rami communicants
• Then they are distributed in the branches of spinal
nerves to smooth muscle in the blood vessels
wall,sweat glands and arrector muscles of hairs of
the skin

16. • The preganglionic fibers travel cephalad in the
sympathetic trunk to synapse in ganglia in the
cervical region
• The postganglionic nerve fibres pass via gray rami
communicants to join the cervical spinal nerves
• Many of preganglionic fibers travel cauded to
synapse in the ganglia of lower lumber and sacral
region
• Again postganglionic fibers pass via gray rami
communicants to join lumber,sacral and coccygeal
spinal nerves

17. • They may pass through the ganglion without
synapsing
• They leave the sympathetic trunk as the greater
splanchnic,lesser splanchnic and least splanchnic
nerves
• The greater splanchnic nerve is formed from the
branches from the 5-9th thoracic ganglia to synapse
with the excitor cells in the ganglia of coeliac
plexus,renal plexus and the suprarenal medulla

18. • The lesser splanchnic nerve is formed from the
branches of the 10 and 11th thoracic ganglia and
descend to join excitor cells in ganglia in the lower
part of coeliac plexus
• The least splanchnic nerve arises from the 12th
thoracic ganglion and synapse with the excitor
neurons in the ganglia of renal plexus
• A few preganglionic fibers travelling in the greater
splanchnic nerve,end directly on the cells of the
suprarenal medulla,are responsible for secretion of
EP and NEP

20. Afferent nerve fiber
• These myelinated nerve fibers travel from the
viscera to sympathetic ganglia without synapsing
• They pass to spinal nerves via white rami
communicants and reach their cell bodies in the
posterior root ganglia of corresponding spinal
nerves
• The central axon then enter the spinal cord and may
form afferent component of local reflex arc or
ascend to hypothalamus

22. Sympathetic Trunks
• The sympathetic trunks are two ganglionated
nerve trunks that extend the whole length of
the vertebral column
• In the neck, each trunk has 3 ganglia
• in the thorax, 11 or 12
• in the lumbar region, 4 or 5 and
• in the pelvis, 4 or 5.
• Below, the two trunks end by joining together
to form a single ganglion, the ganglion impar.

23. PARASYMPATHETIC NERVOUS SYSTEM

24. Parasympathetic Part of the
Autonomic System
• 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.

25. Efferent Nerve Fibers (Craniosacral
Outflow)
• Nerve cells are located in the
brainstem and the sacral segments
of the spinal cord
• Nerve cells in the brainstem form
nuclei in the following cranial
nerves:
1. the oculomotor (parasympathetic
or Edinger-Westphal nucleus),
2. the facial (superior salivatory
nucleus and lacrimatory nucleus),
3. the glossopharyngeal (inferior
salivatory nucleus),
4. the vagus (dorsal nucleus of the
vagus).

26. • The sacral connector nerve
cells are found in the gray
matter of the second, third,
and fourth sacral segments of
the spinal cord.
• The myelinated axons leave
the spinal cord in the anterior
nerve roots of the
corresponding spinal nerves.
• They then leave the sacral
nerves and form the pelvic
splanchnic nerves
• The myelinated efferent fibers
synapse in peripheral ganglia
located close to the viscera
they innervate.

27. • The cranial parasympathetic
ganglia are the ciliary,
pterygopalatine,
submandibular, and otic
• In certain locations, the ganglion
cells are placed in nerve
plexuses, such as the cardiac
plexus, pulmonary plexus,
myenteric plexus (Auerbach
plexus), and mucosal plexus
(Meissner plexus)
• The pelvic splanchnic nerves
synapse in ganglia in the
hypogastric plexuses.

28. Afferent Nerve Fibers
• Afferent myelinated fibers travel from the
viscera to their cell bodies, located either
- in the sensory ganglia of the cranial nerves or
- in the posterior root ganglia of the sacrospinal
nerves.
• The central axons then enter the central
nervous system and take part in the formation
of local reflex arcs or pass to higher centers
such as the hypothalamus.

30. The Large Autonomic Plexuses
Formed by-
1. Large collections of sympathetic and
parasympathetic efferent nerve fibers
2. their associated ganglia,
3. visceral afferent fibers
• In the thorax- cardiac, pulmonary, and esophageal
plexuses.
• In the abdomen- celiac, superior mesenteric, inferior
mesenteric, and aortic plexuses.
• In the pelvis- superior and inferior hypogastric
plexuses.

31. The Enteric Nervous System
• Two important plexuses extend continuously along
the length of the gastrointestinal tract
1. submucous or Meissner plexus
-lies between the mucous membrane and the
circular muscle layer
-concerned with the control of the glands of the
mucous membrane and
2. myenteric or Auerbach plexus
-lies between the circular and longitudinal muscle
layers.
-controls the muscle and movements of the gut
wall.

32. Comparison Between the
Sympathetic and Parasympathetic System
Sympathetic Parasympathetic
Action Prepares body for
emergency
Conserves and
restores energy
Outflow T1-L2 (3) Cranial nerves III, VII,
IX, and X; S2 to 4
Preganglionic
fibers
Myelinated(short) Myelinated(Long)
Ganglia Paravertebral (sympathetic
trunks),
prevertebral (e.g., celiac, superior
mesenteric, inferior mesenteric)
Small ganglia close to viscera (e.g.,
otic, ciliary) or ganglion
cells in plexuses (e.g., cardiac,
pulmonary)
Neurotransmitter
within ganglia
Acetylcholine Acetylcholine
Ganglion-blocking
agents
Hexamethonium and
tetraethylammonium by
competing with acetylcholine
Hexamethonium and
tetraethylammonium by competing
with acetylcholine
Postganglionic fibers Long, nonmyelinated Short, nonmyelinated

33. ` Sympathetic Parasympathetic
Characteristic activity Widespread Discrete
Neurotransmitter at postganglionic
endings
Norepinephrine(most)
acetylcholine at few
endings (sweat
glands,skeletal muscle
blood vesels)
Acetylcholine at all
endings
Blocking agents on receptors of
effector cells
α-adrenergic Receptors
phenoxybenzamine
β-adrenergic receptors
propranolol
Atropine,
scopolamine
Agents inhibiting synthesis and storage
of neurotransmitter at postganglionic
endings
Reserpine
Agents inhibiting hydrolysis of
Neurotransmitter at site of effector
cells
Acetylcholinesterase
blockers(neostigmine)
Drugs mimicking autonomic activity Phenylephrine: α-
receptors
Isoproterenol: beta
receptors
Pilocarpine
Methacholine
Higher control Hypothalamus Hypothalamus

34. Function of ANS and Organ
Specific Innervation
Dr. Azim Anwar
Resident (MD Cardiology)
Phase A

35. Function
Sympathetic and parasympathetic divisions
typically function in opposition to each other.
But this opposition is better termed
Complementary in nature rather than
antagonistic.

36. Sympathetic nervous
system
Responds to stress
Prepare for flight or
fight response
So following
denervation, animal
does not die
immediately IF
THERE IS NO STRESS
Parasympathetic
nervous system
Serves normal/
physiological
function
After denervation,
animal
immediately dies
Necessary for
maintaining
normal/house
keeping function
during minimal
activity…..
Necessary for
coping with the
stress

38. The “Fight or Flight" system
• SYMPATHETIC
“E” activities…...
– Energy production
– Embarrassment
– Exercise
– Excitement
– Emergency

39. PARASYMPATHETIC
“D” activities…….
– Digestion
– Diuretic
– Defecation
– Decrease(HR,RR)

42. Organ Specific Innervation

46. • Eye
• Upper Lid:
 Raised by the levator palpebrae superioris
muscle major part of this muscle is formed by
skeletal muscle innervated by the occulomotor
nerve
 Small part is composed of smooth muscle fibers
innervated
sympathetic fibers from the superior cervical
sympathetic ganglion

47.  Iris:
 The smooth muscle fibers of the iris consist
of circular and radiating fibers. The circular
fibers form the sphincter pupillae, and the
radial fibers form the dilator pupillae
 The sphincter pupillae is supplied by
parasympathetic fibers from the parasympathetic
nucleus (Edinger-Westphal nucleus)
of the oculomotor nerves
 The dilator pupillae is supplied by
postganglionic fibers from the superior
cervical sympathetic ganglion

50. • Lacrimal Gland:
The parasympathetic supply to the
lacrimal gland originates in the
lacrimatory nucleus of the facial nerve.
They increase secretion
The sympathetic fibers arise from the
superior cervical sympathetic ganglion.
They function as vasoconstrictor fibers

51. • Salivary Gland:
• Submandibular and sublingual glands:
 The parasympathetic secretomotor originates
in the superior salivatory nucleus of the facial
N
Sympathetic postganglionic fibers arise from
the superior cervical sympathetic ganglion
They function as vasoconstrictor fibers

52. • Parotid Glands:
Parasympathetic secretomotor fibers
From the inferior salivatory nucleus of
glossopharyngeal nerve supply the gland.
Sympathetic fibers arise from the
superior cervical sympathetic ganglion
They function as vasoconstrictor fibers

53. Autonomic innervation of the parotid gland and

54. Heart:
The sympathetic fibers arise from
the cervical and upper thoracic
portions of the sympathetic trunk
 Results in cardiac acceleration
increased force of contraction (B1)
dilatation of the coronary arteries.

55. The parasympathetic preganglionic fibers
originate
in the dorsal nucleus of the vagus nerve
Activation of these nerves results in
a reduction in the rate and force of
contraction of the myocardium and a
constriction of the coronary arteries (M2)

56. Autonomic innervation of
the hearts and lungs

58. • Lungs:
 The sympathetic fibers arise from the second
to the fifth thoracic ganglia of the sympathetic trunk
 The sympathetic fibers produce Broncho dilatation
and slight vasoconstriction
 The parasympathetic fibers arise from the
dorsal nucleus of the vagus and descend
to the thorax within the vagus nerves
 The parasympathetic produce bronchoconstriction ,
slight vasodilatation and increase glandular secretion

60. Autonomic innervation of
the hearts and lungs

61. • Gastrointestinal Tract:
• Stomach and Intestine as Far as Splenic Flexure:
parasympathetic fibers enter the abdomen
in the anterior (left) and posterior (right) vagal trunks
Are distributed to many abdominal viscera
and to the gastrointestinal tract from the
stomach to the splenic flexure of the colon

62. Gastrointestinal contiued
 The parasympathetic nerves stimulate peristalsis
and relax the sphincters; they also stimulate secretion
 Sympathetic nerve fibers pass through the thoracic part
of the sympathetic trunk and enter the greater and lesser
splanchnic nerves
 The sympathetic nerves inhibit peristalsis and cause
contraction of the sphincters; they also inhibit
secretion

63. • Descending Colon ,Pelvic Colon, and Rectum:
 parasympathetic fibers originate in the gray matter of the
spinal cord from the 2nd to the 4th sacral segments. The
postganglionic fibers supply the smooth muscle & glands
 parasympathetic nerves stimulate peristalsis and
secretion.

64. Descending
colon ,pelvic colon ,rectum continued
 The sympathetic nerve fibers pass via the lumbar part of
the sympathetic trunk.
 The sympathetic nerves inhibit peristalsis & secretion
 The sphincter is innervated by postganglionic sympathetic
fibers from the hypogastric plexuses. The sympathetic
nerves cause the internal anal sphincter to contract

65. Autonomic innervation of

66. • Gallbladder and Biliary Ducts:
The gallbladder & biliary ducts receive
postganglionic parasympathetic & sympathetic
fibers from the hepatic plexus
Parasympathetic fibers derived from the vagus are
thought to be motor to the smooth muscle of the
gallbladder & bile ducts and inhibitory to the
sphincter of Oddi.
sympathetic fibers relaxes the Gallbladder

67. • Kidney:
sympathetic fibers pass through the lower thoracic
part of the sympathetic trunk & the lowest thoracic
splanchnic nerve to join the renal plexus around
the renal artery
The sympathetic nerves are vasoconstrictor in
action to the renal arteries within the kidney
Renin release (B1)
 parasympathetic fibers enter the renal plexus
from the vagus. The parasympathetic nerves
are thought to be vasodilator in action

68. • Medulla of Suprarenal Gland:
 Sympathetic fibers descend to the gland in
the greater splanchnic nerve, a branch of the
thoracic part of the sympathetic trunk
 The sympathetic nerves stimulate the increase
the output of epinephrine and norepinephrine
 There is no parasympathetic innervation of the medulla
of the suprarenal gland

69. Autonomic innervation of
kidney and Suprarenal Gland

70. Involuntary Internal Sphincter of the Anal
Canal:
The sphincter is innervated by postganglionic
sympathetic fibers from the hypogastric
plexuses
The sympathetic nerves cause the internal anal
sphincter to contract

71. • Urinary Bladder:
The sympathetic fibers originate in the
first and second lumbar ganglia of the
sympathetic trunk and travel to the
hypogastric plexuses
The parasympathetic fibers arise as the
pelvic splanchnic nerves from the second,
third, and fourth sacral nerves

72.  The sympathetic nerves to the detrusor muscle have
little or no action on the smooth muscle of the bladder
wall and are distributed mainly to the blood vessels
 sympathetic nerves to the sphincter vesicae play only
a minor role in causing contraction of the sphincter in
maintaining urinary continence (alpha 1)
 The parasympathetic nerves stimulate the contraction of
the smooth muscle of the bladder wall and, in some way,
inhibit the contraction of the sphincter vesicae

73. Autonomic
innervation of the
Urinary bladder

74. • Male Reproductive organs:
 The initial vascular engorgement is controlled by the
parasympathetic part of the autonomic nervous system results in
erection.
 The parasympathetic fibers originate in the gray matter of the 2nd,
3rd and 4th sacral segments of the spinal cord

75. Male reproductive organ contd…..
The sympathetic nerves stimulate the contractions of the
smooth muscle in the walls of these structures & cause
the spermatozoa, together with the secretions of the
seminal vesicles & prostate, to be discharged into urethra

76. Autonomic innervations
of the male
reproductive tract

77. • Uterus:
Preganglionic sympathetic nerve fibers leave the
spinal cord at segmental levels T12 and L1 supply
the smooth muscle of the uterus
Parasympathetic preganglionic fibers leave the
spinal cord at levels S2–4
Although it is recognized that the uterine muscle is
largely under hormonal control, sympathetic
innervation may cause uterine contraction and
vasoconstriction
whereas parasympathetic fibers have the opposite
effect

78. Autonomic innervations
of the female
reproductive tract

79. • Arteries of the Limbs:
The arteries of the upper and lower limb are
innervated by sympathetic nerves
The sympathetic nerves cause vasoconstriction
of cutaneous arteries and vasodilatation of
arteries that supply skeletal muscle

80. • Arteries of the Lower Limb
• The preganglionic fibers originate from cell bodies in the
second to the eighth thoracic segments of the spinal cord
 The preganglionic fibers originate from cell bodies in the lower
three thoracic and upper two or three lumbar segments of the
spinal cord

84. Higher Control of the Autonomic
Nervous System
• Stimulation of the anterior region of the
hypothalamus can influence parasympathetic
responses
• stimulation of the posterior part of the
hypothalamus gives rise to sympathetic
responses.

85. Put It All
T.…O...G..E.T..H...E….R

87. Effects of Autonomic Nervous System on
Organs of the Body
Organ Sympathetic Action Parasympathetic
Action
eye Pupil Dilates Constricts
Ciliary muscle Relaxes Contracts
glands Lacrimal, parotid,
Submandibular, sublingual,
Nasal glands
Reduce secretion by
Causing vasoconstriction
of blood vessels
Increase
secretion
Sweat Increase secretion
heart Cardiac muscle Increases force
of contraction
Decreases force of
contraction
Coronary arteries Dilates (β receptors),
constricts (α receptors)
lungs Bronchial muscle Relaxes (dilates
bronchi)
Contracts
(constricts bronchi)
Bronchial secretion Increases secretion
Bronchial arteries Constricts Dilates

88. Organ Sympathetic action Parasympathetic action
Gastrointestinal
tract
Muscle in walls Decreases peristalsis Increases
peristalsis
Muscle in
sphincters
Contracts Relaxes
Glands Reduces secretion Increases secretion
Liver Breaks down glycogen
into glucose
Gallbladder Relaxes Contracts
Kidney Decreases output due to
constriction of
arteries
Urinary bladder Bladder wall Relaxes Contracts
Sphincter vesicae Contracts Relaxes
Erectile tissue of
penis and clitoris
Relaxes,
Causes erection
Ejaculation Contracts smooth muscle
of vas deferens,
seminal vesicles and
prostate

89. Organ Sympathetic action Parasympathetic
action
Systemic arteries Skin Constrict
Abdominal Constrict
Muscle Constrict (alpha receptors),
dilate (beta receptors),
Dilate (cholinergic)
Erector pili
muscles
Contract
Suprarenal Cortex Stimulates
Medulla Liberates
epinephrine and
norepinephrine

90. Autonomic Ganglia
and ANS
Dysfunction
Dr. Al Amin

91. • The autonomic ganglia is the site
where preganglionic nerve fibres
synapse on postganglionic neurons
• An autonomic ganglia consists of a
collection of multipolar neurons
together with satellite cells and a
connective tissue capsule
• Preganglionic nerve fibres enter the
ganglion and postganglionic nerve
fibres leave the ganglion that have
arisen from neurons within the
ganglion

92. • Small intensely fluorescent
cells(SIF) are small interneuron's
who receive preganglionic
cholinergic fibers in some ganglion
and may modulate ganglionic
transmission
• Preganglionic fibers are
myelinated, small and relatively
slow conducting B fibers
• Postganglionic fibers are
unmyelinated, smaller and slow
conducting C fibers

93. • Basically 2 types of ganglia :
sympathetic and parasympathetic
• Sympathetic ganglia form part of
the sympathetic trunk and
prevertebal in position
• Parasympathetic ganglia are
situated close to viscera

94. Parasympathetic
ganglia
Parasympathetic ganglia are four
paired who supply the all
parasympathetic innervations to
head and neck
• Ciliary ganglion(sphincter
pupillae,ciliary muscle)
• Otic ganglia(parotid gland)
• Submandibular
ganglion(submandibular and
sublingual gland)
• Pterygopalatine ganglion(lacrimal
glands, glands of nasal cavity)

95. Parasympathetic ganglia

96. Ciliary ganglia
 Located just behind the eye in the
posterior orbit
The oculomotor nerve coming into
the ganglion contains preganglionic
axons from Edinger-Westphal
nucleus which form synapses with
the ciliary neurons
 The postganglionic axons run in the
short ciliary nerves and innervate
two eye muscles
 Sphincter pupillae constricts the
pupil,ciliary muscle helps in
accomodation

98. • Three types of nerve fibers run
through the ciliary
ganglia:parasympathetic
fibers,sympathetic fibers and
sensory fibers
• Only parasympathetic fibers form
synapses in the ganglion,the other
two types of nerve fibers do not
synapse

99. Ciliary ganglia

100. Parasympathetic root
• Presynaptic parasympathetic fibers
originate in the Edinger-Westphal
nucleus and oculomotor nucleus in
the brainstem
• Exit together as the oculomotor
nerve—pass through the lateral wall
of cavernous sinus
• Enters the orbit through the
superior orbital fissure—divides into
branches that innervate the levator
palpebrae superiors and four of the
extraocular muscles

101. Parasympathetic root
• Postsynaptic parasympathetic
fibers leave ciliary ganglion in
multiple short ciliary nerves---
enter the posterior aspect of the
eyeball--- innervate the sphincter
pupillae and ciliaris muscles
• Sphincter pupillae constricts the
pupil and ciliaris muscle changes
the shape of the lens for
accomodation

102. Sensory root
• Sensory fibers from the
eyeball(cornea,iris&ciliary body) run
posteriorly through the short ciliay
nerve—ciliary ganglion—nasociliary
nerve branch of opthalmic nerve—
signals travel back through the
opthalmic nerve to trigeminal
nerve—goes to thalamic nuclei of
cerebral cortex

103. Sympathetic root
• Preganglionic sympathetic fibers
originate from neurons in the
intermediolateral column of thoracic
spinal cord at the level of T1 and T2
than ---synapses in superior cervical
ganglia
• Postganglionic sympathetic fibers
ascend with the intercal carotid
artery as carotid plexus—at
cavernous sinus they separate from
plexus---run through superior orbital
fissure—supply as long ciliary and
short ciliary nerves
• Sympathetic fibers pass through the
ganglia without forming synapse

104. Sympathetic root
• Sympathetic fibers from superior cervical
ganglion innervate blood
vessels(vasoconstriction),sweat glands and 5
eye muscles:dilator pupillae,ciliary
muscle,superior tarsal muscle,inferior tarsal
muscle and orbitalis

105. Otic ganglion
• The otic ganglion is a small
parasympathetic ganglion located
below the foramen ovale in the
infratemporal fossa and on the
medial surface of the mandibular
nerve
• It innervates the parotid gland for
salivation

106. Otic ganglion
• The preganglionic parasympathetic
fibers originate in the inferior
salivatory nucleus of
glossopharyngeal nerve—pass via
lesser petrosal nerve to otic ganglia—
the fiber synapse—postganglionic
fibers pass through auriculotemporal
nerve—parotid gland—produce
vasodilator and secretomotor effects
• Sympathetic fiber pass through the
ganglion without relay and reach the
parotid gland via auriculotemporal
nerve—vasomotor in action

107. Otic ganglion
• The motor fibers supply the medial
pterygoid,tensor palati,tensor tympani muscle
• The ganglion also connected to the chorda
tympani nerve and relay the sense of taste
from the anterior two thirds of the tongue

108. Otic ganglion

109. Submandibular ganglion
• Submandibular ganglion is situated
above the submandibular gland on
the hyoglossal muscle
• Sympathetic fibers come from the
external carotid plexus via the fascial
nerve and its branches
• Preganglionic parasympathetic fibers
from the superior salivatory nucleus
of pons—through chordae tympani
and lingual nerve—synapse at
ganglion

110. Submandibular
ganglion
• Postganglionic parasympathetic
fibers supply submadibular and
sublingual salivary gland.They are
secretomotor to the gland

111. Submandibular ganglion

112. Pterygopalatine ganglion
• The pterygopalatine ganglion is
found in the pterygopalatine fossa.It
is largely innervated by the greater
petrosal nerve and its axon project
to the lacrimal glands and nasal
mucosa
• The pterygopalatine ganglion
supplies the lacrimal gland,paranasal
sinuses,glands of nasal cavity and
pharynx,gingiva,mucous membrane
and glands of hard palate

113. Pterygopalatine ganglion
• Sensory root is derived from two
sphenopalatine branches of the
maxillary nerve—palatine
nerves—enter the ganglion
• Parasympathetic root is derived
from the nervous
intermedius(part of the facial
nerve) through the greater
petrosal nerve from where
preganglionic fiber arise

114. Pterygopalatine ganglion
• Postganglionic fibers are vasodilator
and secretory—distributed with deep
branches of trigeminal nerve to the
mucous membrane of the nose,soft
palate,tonsils,uvula,upper lip and
gums and via lacrimal nerve to
lacrimal gland
• Sympathetic fibers arise from the
superior cervical ganglia—deep
petrosal nerve—nerve to pterygoid
canal—enter the ganglion

116. Sites of synapses between pre
and post sympathetic
ganglia
• sympathetic trunk ganglia
- located from base of skull
to coccyx
• Pre vertebral ganglia
- innervates organs below
the diaphragm

117. Sympathetic Trunk Ganglia

119. CLINICAL SIGNIFICANCE OF AUTONOMIC
NERVOUS SYSTEM

120. Diseases Involving the Autonomic
Nervous System
• Diabetic Neuropathy : Common causes of
peripheral neuropathy involving sensory ,
motor also include autonomic nervous system

122. Horner Syndrome
• Horner syndrome consists of
(1) constriction of the pupil (miosis),
(2)slight drooping of the eyelid (ptosis),
(3) enophthalmos,
(4) vasodilation of skin arterioles, and
(5) loss of sweating (anhydrosis).
• All these symptoms result from an interruption
of the sympathetic nerve supply to the head and
neck.

123. • Pathologic causes include lesion in brainstem
or cervical part of spinal cord that interrupts
reticulospinal tracts descending from
hypothalamus to the sympathetic outflow
• Such lesion include multiple sclerosis and
syringomyelia

124. Argyll Robertson Pupil
• Argyll Robertson pupil is characterized by a small
pupil, which is of
1. fixed size and
2. does not react to light
3. but does contract with accommodation.
• caused by a neurosyphilitic lesion interrupting the
fibers that run from the pretectal nucleus to the
parasympathetic nuclei of the oculomotor nerve
on both sides.

125. Adie tonic pupil syndrome
• Pupil has a decreased or absent light reflex
• A slow or delayed contraction to near vision
• And a slow or delayed dilatation in the dark
• Results from a disorder of the
parasympathetic innervation of the constrictor
pupillae muscle
• Confirmed by looking for hypersensitivity to
cholinergic agents

126. Frey Syndrome
• Often results as a side effect of penetrating
wound of the parotid gland.
• During the process of healing, the postganglionic
parasympathetic secretomotor fibers traveling in
the auriculotemporal nerve grow out and join the
distal end of the great auricular nerve, which
supplies the sweat glands of the overlying facial
skin. By this means, a stimulus intended for saliva
production instead produces sweat secretion.

127. • A similar syndrome may follow injury to the
facial nerve. During the process of
regeneration, parasympathetic fibers normally
destined for the submandibular and
sublingual salivary glands are diverted to the
lacrimal gland. This produces watering of the
eyes associated with salivation, the so-called
crocodile tears

128. Hirschsprung Disease
(megacolon)
• Is a congenital condition in which there is a
failure of development of the myenteric plexus
(Auerbach plexus) in the distal part of the colon.
• The involved part of the colon possesses no
parasympathetic ganglion cells, and peristalsis is
absent.
• This effectively blocks the passage of feces, and
the proximal part of the colon becomes
enormously distended.

129. Urinary Bladder Dysfunction
Following Spinal Cord Injuries
• The normal bladder is innervated as follows:
• Sympathetic innervation is from the first and
second lumbar segments of the spinal cord.
• Parasympathetic innervation is from the
second, third, and fourth sacral segments of
the spinal cord.
• Sensory nerve fibers enter the spinal cord at
the above segments.

130. • The atonic bladder occurs during the phase of spinal
shock immediately following the injury and may last
from a few days to several weeks.
• The bladder wall muscle is relaxed, the sphincter
vesicae is tightly contracted (loss of inhibition from
higher levels), and the sphincter urethrae is relaxed.
• The bladder becomes greatly distended and finally
overflows.
• Depending on the level of the cord injury, the patient
may or may not be aware that the bladder is full; there
is no voluntary control.

131. • Automatic reflex bladder occurs after the patient
has recovered from spinal shock
• Provided that cord lesion lies above the level of
parasympathetic outflow
• Normally found in infancy
• Since the descending fibres in the spinal cord are
sectioned,there is no voluntary control
• The bladder fills and empties reflexly
• Known as spastic neurogenic bladder

132. • The autonomus bladder is the condition that
occurs if the sacral segment of spinal cord or
cauda equina is destroyed
• No reflex control or voluntary control
• Bladder wall is flaccid,overflows, resulting in
continuous dribbling

133. • Uninhibited bladder is associated with urge
incontinence with sudden uncontrolled
evacuation and having no residual urine
• Results from lesions affecting frontal lobe,
parasagittal meningioma or aneurysm of
anterior communicating artery

134. Dysfunction in Defecation Following
Spinal Cord Injuries
• The involuntary internal sphincter of the anal
canal normally is innervated by postganglionic
sympathetic fibers from the hypogastric
plexuses
• the voluntary external sphincter of the anal
canal is innervated by the inferior rectal nerve.
The desire to defecate is initiated by
stimulation of the stretch receptors in the wall
of the rectum.

135. • Following severe spinal cord injuries (or cauda
equina injuries), the patient is not aware of
rectal distention. Moreover, parasympathetic
influence on the peristaltic activity of the
descending colon, sigmoidcolon, and rectum
is lost.

136. Dysfunction in Erection and
Ejaculation Following Spinal Cord
Injuries
• The erection of the penis or clitoris is
controlled by the parasympathetic nerves that
originate from the second, third, and fourth
sacral segments of the spinal cord.
• Bilateral damage to the reticulospinal tracts in
the spinal cord above the second sacral
segment of the spinal cord will result in loss of
erection.

137. • Ejaculation is controlled by sympathetic
nerves that originate in the first and second
lumbar segments of the spinal cord.
• severe bilateral damage to the spinal cord
results in loss of ejaculation.

138. • Sympathectomy is done as a method of
treating arterial disease , Like
Raynaud disease
Intermittent claudication
Hypertention