1. Prepared by: ANAM KHAN

3. 
Brain and spinal cord:
Receives and processes incoming
sensory information and responds by
sending out signals that initiate or modify
a process.

4.  Includes
all the neurons and ganglia found
outside the CNS-any nerve that enters
or leaves the CNS

5. 
The main function of the PNS is to connect the
CNS to the limbs and organs, essentially
serving as a communication
relay going back and forth between the brain
and the extremities.

It is subdivided into:

6. 
Efferent Division – the neurons of which carry
signals away from the brain and spinal cord to
peripheral tissues.

7. 
= Afferent division – the neurons of which bring
info from the periphery to the CNS.They provide
sensory input to modulate the function of efferent
division.

10.  Efferent
Somatic
Autonomic

11.  Somatic
efferent neurons are Involved in the
voluntary control of functions

12. Autonomic Efferent Regulates everyday
requirement of vital bodily functions without the
conscious participation of the mind.

13. 
Preganglionic neurons



Cell body is located
within the CNS
Postganglionic neurons
Cell body originating
in the ganglion

14. preganglionic


Either
unmyelinated or
myelinated
Emerge from
brainstem or spinal
cord and make
synaptic connection
in ganglia
postganglionic

Generally
Nonmyelinated

Terminates on
effector organs

15. 
These fibers
arise from the
cranium (from
cranial
nerves
III,VII,IX and
X) and from the
sacral
region(S2-4) of
spinal cord.

16. Efferent nerve fibers
originate from nerve
cells in the lateral
gray column of the
spinal cord between
first thoracic and
second lumbar
segments( thoracic
outflow)

17. 
Two types of acetylcholine receptors exists

18.  Acetylcholine
has the ability to bind
with both of these receptors.

19. 
In preganglionic neurons, both
parasympathetic and sympathetic, the
release of acetylcholine binds
predominantly with nicotinic
receptors
neurons
on the postganglionic

20. Sympathetic system:
•At the synapses within the ganglia, preganglionic
neurons release acetylcholine.
•In response to this stimulus postganglionic neurons with two important exceptions - release nor
epinephrine.
•Activates adrenergic receptors on the peripheral
target tissues.

21. The activation of
target tissue
receptors causes
the effects
associated with
the sympathetic
system.

22. The two exceptions mentioned above are:
•
postganglionic neurons of
sweat glands and
• chromaffin cells of the
adrenal medulla.

23. Parasympathetic system
 The parasympathetic nervous system uses
chiefly acetylcholine (ACh) as its
neurotransmitter.
 Most transmissions occur in two stages:

24. •When stimulated, the preganglionic nerve releases
ACh at the ganglion.
•which acts on nicotinic receptors of
postganglionic neurons.
•The postganglionic nerve then releases ACh to
stimulate the muscarinic receptors of the target
organ.

27. 
Both always present in the blood.

Nor epinephrine varies

Epinephrine is a constant

28. 
3rd division of ANS

Works independently of CNS

29.  Brain
of Gut ( as it
is the collection of
nerve fibers that
innervate the
gastrointestinal tract ,
pancreas and gall
bladder)

30. 
Modulated by both the parasympathetic and
sympathetic nervous system

31.  Exocrine/endocrine
secretions
 and microcirculation of
gastrointestinal tract

33. 
Continually active to some degree

Diffused distribution of postganglionic
Fibers.

34. 
The changes experienced by the body during
emergencies have been referred to as the “fight
or flight” response.

35.  Maintains

essential bodily functions
Generally dominant over sympathetic system in
“Rest
and Digest”
situations.

36. 
It usually acts to oppose or balance the
actions of sympathetic division.

39. 
Eye
P-constricts pupils ( III occulomotor)
S-dilates pupils

40. 
Heart muscles
P-decreases rate; slows and steadies
heart(bradycardia)
S-Increases rate and force of heartbeat

41. 
Blood vessels
P-vasoconstriction
S- vasodilation

42. 
Glands (nasal, lacrimal, salivary, gastric,
pancreas)
P-stimulates secretary activity
S-inhibits secretary activity

43. 
Lungs
P-constricts bronchioles
S-Dilates bronchioles and mildly constricts
blood vessels

44. 
Digestive Tract Organs:
P-increases motility and amount of
secretions by digestive organs' relaxes
sphincters and allow movement of food
along tract
S-decreases activity of glands and muscles of
digestive system and constricts sphincte r;
causes vasoconstriction

45. Sweat Glands
S-stimulates sweating


Arrector pili muscles attached to hair follicle
S-stimulates to contract—Goosebumps

46. Liver
S-Epinephrine stimulates liver to release glucose
to blood


47. Adrenal Medulla
S-Stimulates
medulla cells to
secrete
epinephrine and
noreponephrine
into bloodstream

48. 

Kidney
S- causes vasoconstriction; decreases urine
output

49. 
Gallbladder
P-stimulates activity; gallbladder contracts to expel bile
S-gallbladder relaxed

Bladder, Urethra
P-contraction smooth muscle of bladder wall
S-relaxation of smooth muscle of bladder wall

51. Summary
51