Sympathetic is the "FIGHT OR FLY" parasympathetic is the "DIGEST+REST+ SEX". both of them are alternating for their job

1. AUTONOMIC NERVOUS SYSTEM
& CRANIAL NERVES
22-12-2019

2. • The word autonomous is taken from Greek words, the
autos meaning ‘self’ and the nomos meaning ‘control’.
• ANS is an involuntary system.
• it controls the vegetative functions, it is also called
vegetative system (smooth muscle, cardiac muscle,and
glands).
• The autonomic nervous system (ANS) collects the
information about the changes that take place in the
internal environment (i.e. internal viscera), interprets
these changes and guides the actions.
• ANS controls the various vegetative functions.
• ANS maintain constant internal environment
(homeostasis).

3. Autonomic Centers in the Brain
1. Pons
2. Medulla oblongata.
3. Hypothalamus “the greatest center”.
4. Amygdala
5. Red nucleus of the stria terminalis
6. Cerebral cortex.

4. DIVISIONS OF ANS:
• From anatomical and physiological point of
view, ANS is divided into two divisions:
1. Sympathetic division
2. Parasympathetic division.

5. General arrangement of the A.N.S:
• Preganglionic nerve fibres:
1. Are nerve fibers that originate from the
nervous system.
2. Type B nerve fibres.
3. Myelinated and “white colour”.
• Postganglionic nerve fibres:
1. Are those arising from the autonomic ganglia.
2. Type C nerve fibres.
3. Unmyelinated and “gray colour”.

6. Somatic and autonomic
nervous system efferent
pathways

7. SYMPATHETIC DIVISION:
• Called thoracolumbar outflow.
• Sympathetic division supplies smooth muscle
fibers of all the visceral organs such as blood
vessels, heart, lungs, glands, gastrointestinal
organs.
• SYMPATHETIC GANGLIA:
A. Paravertebral or sympathetic chain ganglia
B. Prevertebral or collateral ganglia
C. Terminal or peripheral ganglia.

8. • Paravertebral or Sympathetic Chain Ganglia:
1. Cervical ganglia : 8 in number (superior, middle, inferior)
2. Thoracic ganglia : 12 in number
3. Lumbar ganglia : 5 in number
4. Sacral ganglia : 5 in number.
• Prevertebral or Collateral Ganglia:
1. Celiac ganglion
2. Superior mesenteric ganglion
3. Inferior mesenteric ganglion.
• Terminal or Peripheral Ganglia:
1. Heart
2. Bronchi
3. pancreas

9. Types of sympathetic ganglion:

10. • SYMPATHETIC FIBERS:
1. Preganglionic fibers: Acetylcholine (Ach).
2. Postganglionic noradrenergic fibers:
Noradrenaline.
3. Postganglionic cholinergic fibers: Ach.

11. Sympathetic pathway at a spinal segment:

13. Segmental distribution of sympathetic
fibers:

14. PARASYMPATHETIC DIVISION:
• called the craniosacral outflow.
• fibers of this division arise from brain and sacral segments
of spinal cord.
• CRANIAL OUTFLOW OR CRANIAL PORTION OF
PARASYMPATHETIC DIVISION:
1. Oculomotor (III) nerve:
2. Facial (VII) nerve
3. Glossopharyngeal (IX) nerve
4. Vagus (X) nerve.
• Preganglionic fibers are longer and reach the
postganglionic neurons, which are situated within the
organs or close to the organs innervated by these nerves.
(Bulbar level or bulbar outflow)
(Tectal or midbrain outflow)

17. • SACRAL OUTFLOW OR SACRAL PORTION OF
PARASYMPATHETIC DIVISION:
• arises from the sacral segments of spinal.
• innervates smooth muscles forming the walls
of viscera and the glands such as large
intestine, liver, spleen, kidneys, bladder,
genitalia,spermatic cord.

18. • PARASYMPATHETIC FIBERS
1. Preganglionic fibers: Ach
2. Postganglionic fibers: Ach

26. APPLIED ASPECTS:
• Autonomic drugs: (agonists and antagonists).
• Autonomic failure:
A) Primary Autonomic failure:
• unexplained (primary) autonomic neuronal
degeneration.
B) Secondary autonomic failure:
1. Diabetes mellitus (most common), amyloidosis,
beriberi, syringomyelia, tabes dorsalis and subacute
combined degeneration of spinal cord.
2. Patients receiving sympatholytic drugs.
3. Prolonged bed rest.

27. Features of Autonomic Dysfunctions:
1. Cardiovascular features: include tachycardia and
orthostatic hypotension.
2. Sudomotor features: are anhidrosis and heat intolerance
or hyperhydrosis.
3. Gastrointestinal features: include constipation, occasional
diarrhoea, dryness of mouth occurs frequently and
dysphagia.
4. Urinary features: are nocturia, frequency, urgency,
incontinence and retention of urine.
5. Reproductive organ problems: include erectile and
ejaculation failure, decreased vaginal lubrication.
6. Ocular features: include miosis and enophthalmos.
7. Neurological symptoms:Weakness, lethargy and giddiness

28. Cranial nerves:

29. • Twelve pairs of cranial nerves are associated with
the brain.
• In most cases, the names of the cranial nerves reveal
either the structures they serve or their functions.
• The nerves are also numbered (using Roman
numerals).
• The numbers indicate the order, from anterior to
posterior.
• You might make up your own saying to remember
the first letters of the cranial nerves in order, or use
the following memory jog sent by a student: “On
occasion, our trusty truck acts funny—very good
vehicle anyhow.”
• Oh Oh Oh To Touch And Feel Very Green Vegetables
AH

30. • Cranial nerves (I, II, and VIII): sensory nerves.
• Cranial nerves (III, IV, VI, XI, and XII): motor
nerves.
• Cranial nerves (V, VII, IX, and X): mixed
nerves.