Autonomicnervoussystem

1. Nervous 3
Autonomic Nervous System
McKinley and O’Laughlin
Chapter 18

2. Introduction
 What part of the vertebrate nervous system
innervates smooth and cardiac muscle and
glandular tissues and governs involuntary,
vital functions?

3. The ANS affects the following:
 heart rate
 digestion
 respiration rate
 salivation
 perspiration
 diameter of the pupils
 micturition (urination)
 sexual arousal

4.  Whereas most of its actions are involuntary, some
actions of the ANS, such as breathing, work in
tandem with the conscious mind.

5. The ANS is:
 Purely motor (though some references
include visceral sensory as an arm of the
ANS)
 A functional, not anatomical, division
 Opposite is the somatic nervous system
 Mostly working beyond our conscious
awareness

6. Autonomic vs. Somatic
 If we follow a nerve impulse from the CNS
to an effector within the SNS, how many
motor neurons would be involved?
 If we follow a nerve impulse from the CNS
to an effector within the ANS, how many
motor neurons would be involved?

8. Autonomic vs. Somatic
 A motor neuron within the ANS that lies
between the CNS and a ganglion is what
type of neuron?
 Pre-ganglionic - myelinated
 A motor neuron within the ANS that lies
between a ganglion and an effector is what
type of neuron?
 Ganglionic - unmyelinated

9. Autonomic vs. Somatic
 What is the axon of a ganglionic neuron
with in the ANS?
 Post-ganglionic axon

10. ANS Divisions
 What are the 2 divisions of the ANS?
 Sympathetic division
 Parasympathetic division

11. ANS Divisions
 What division of the ANS is primarily
concerned with conserving energy and
replenishing nutrient stores and has been
nicknamed the “rest-and-digest” division?
 Parasympathetic division

12. ANS Divisions
 What division of the ANS is primarily
concerned with preparing the body for
emergencies and is often referred to as the
“fight-or-flight” division?
 Sympathetic division

13.  The parasympathetic division is sometimes
referred to as “craniosacral” because the
nerves arise from the brain stem (mainly
vagus) & sacral region
 The sympathetic division is sometimes
referred to as “thoracolumbar” because of
the sympathetic neurons in the spinal nerves
of these regions.

16. Parasympathetic Division
 What is another term for the
parasympathetic division?
 _________ division

17. Parasympathetic Division
 Where are the cell bodies of the
preganglionic neurons for the
parasympathetic division located?
 Brainstem
 S2-S4 (lateral gray matter of spinal cord)

18. Parasympathetic Division
 Where are the ganglia of the
parasympathetic division found?
 Terminal ganglia - close to target organ
 Intramural ganglia - within wall of target organ

20. Parasympathetic Division
 What cranial nerves carry parasympathetic
fibers?
 III Oculomotor
 VII Facial
 IX Glossopharyngeal
 X Vagus

21. Parasympathetic Division
 The parasympathetic division innervates
what structures through the oculomotor
nerve?
 Ciliary muscle
 Pupillary constrictor of iris
 Dilator controlled by sympathetic division

22. Parasympathetic Division
 The parasympathetic division innervates
what structures through the facial nerve?
 Submandibular and sublingual glands
 Lacrimal gland
 Glands of nasal cavity, mouth, and palate

23. Parasympathetic Division
 The parasympathetic division innervates
what structures through the
glossopharyngeal nerve?
 Parotid gland

24. Parasympathetic Division
 The parasympathetic division innervates
what structures through the vagus nerve?
 Thoracic and abdominal organs

26. Parasympathetic Division
 What specific regions of the spinal cord
house the cell bodies of the parasympathetic
division of the ANS?
 Lateral horns

27. Parasympathetic Division
 What nerves carry fibers of the
parasympathetic division of the ANS
through the pelvis?
 Pelvic splanchnic nerves
 What does ‘splanchnic’ mean?
 Visceral

29. Parasympathetic Effects
 Increase saliva production
 Constrict pupils
 Constrict airways
 Produce tears
 Increase GI motility
 Contract bladder
 Erect penis/clitoris

30. Sympathetic Division
 What is another term for the sympathetic
division?
 _____________ division
 From what regions of the CNS does the
sympathetic division arise?
 T1-L2 (lateral horns of spinal cord)

31. Sympathetic Division
 What part of spinal nerves do the
preganglionic sympathetic axons travel
within as they leave the lateral horn of the
spinal cord?
 Anterior root

32. Sympathetic Division
 What sympathetic ganglia lie on the left and
right sides of the vertebral column from T1-
L2?
 Sympathetic trunk ganglia
 Paravertebral ganglia
 What structure of the sympathetic division
has the appearance of a pearl necklace?
 Sympathetic trunk (ganglia and axons)

33. Sympathetic Division
 What clusters of ganglia of the sympathetic
division of the ANS lie within the neck?
 Cervical ganglia
 What are the connections between spinal
nerves and the sympathetic trunks?
 Rami communicantes

35. Sympathetic Division
 What structures carry preganglionic
sympathetic axons from the T1-L2 spinal
nerves to the sympathetic trunk?
 White rami
 What structures carry postganglionic
sympathetic axons from the sympathetic
trunk to the spinal nerves?
 Gray rami

38. Sympathetic Division
 What structures are composed of
preganglionic axons that do not synapse in a
sympathetic trunk ganglion?
 Splanchnic nerves
 Splanchnic nerves of the sympathetic
division of the ANS terminate in what
structures?
 Prevertebral (collateral) ganglia

39. Sympathetic Division
 What structures are singular rather than
paired, are anterior to the vertebral column,
and are located only in the abdominal
cavity?
 Prevertebral ganglia

40. Sympathetic Division
 List the 3 prevertebral ganglia
 Celiac
 Superior mesenteric
 Inferior mesenteric

42. Sympathetic Pathways
 What pathway is a postganglionic axon
within if it travels through a gray ramus that
is at the same level as the ganglionic neuron
to innervate blood vessels or arrector pili
muscles or sweat glands?
 Spinal nerve pathway

43. Sympathetic Pathways
 What pathway is a postganglionic axon
within if the preganglionic neuron synapses
with a ganglionic neuron in a sympathetic
trunk ganglion, but the postganglionic axon
does not leave the trunk via a gray ramus,
but instead extends away from the
sympathetic trunk ganglion and goes
directly to the effector organ?
 Postganglionic sympathetic nerve pathway

45. Sympathetic Pathways
 What pathway is a postganglionic axon
within if the preganglionic axon passes
through the sympathetic trunk ganglia
without synapsing and extends to the
prevertebral ganglia?
 Splanchnic nerve pathway

46. Sympathetic Pathways
 What pathway is a sympathetic axon within
if it goes to the adrenal medulla?
 Adrenal medulla pathway

48. Sympathetic Effects
 Pupil dilation
 Airway dilation
 Sweat production
 Mass activation response to stress
 Increased heart rate, blood pressure, breathing
rate and depth, dilate pupils, stimulate RAS

49. Autonomic Nervous System
 Usually both divisions of the ANS innervate
organs. Where does this dual innervation
not occur?
 Cutaneous region
 Includes peripheral blood vessels
 Sympathetic only

50. Autonomic Plexuses
 What are collections of sympathetic
postganglionic axons, parasympathetic
preganglionic axons, and some visceral
sensory axons?
 Autonomic plexuses

51. Autonomic Plexuses
 List the 5 autonomic plexuses
 Cardiac plexus
 Esophageal plexus
 Pulmonary plexus
 Abdominal plexus
 Hypogastric plexus

53. CNS Control of ANS
 What part of the CNS has the greatest
control over the ANS?
 Hypothalamus
 What part of the CNS holds nuclei which
have a great deal of influence over
autonomic function?
 Brain stem

55. CNS Control of ANS
 What division of the ANS may process and
control certain functions at the level of the
spinal cord without involvement of the
brain?
 Parasympathetic
 E.g. Defecation and urination

57.  How does the
parasympathetic
reflex for urination
relate to potty
training?

58. The End of Autonomic Nervous System
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