Lecture. 2 - Autonomic Nervous System.ppt

Study Note
Lecture Slide
Autonomic Nervous System

1. Lecture 2 Lecture 2
The Autonomic Nervous The Autonomic Nervous
SystemSystem
James B. Parker Ph.D.James B. Parker Ph.D.
Physiology 1Physiology 1
Lecture Outline 2Lecture Outline 2

2. The Autonomic Nervous SystemThe Autonomic Nervous System

OBJECTIVES:OBJECTIVES:

1. The student should be able to define the 1. The student should be able to define the
organization and function of the autonomic organization and function of the autonomic
nervous system (ANS).nervous system (ANS).

2. The student should be able to define the 2. The student should be able to define the
effects of the ANS.effects of the ANS.

3. The student should be able to list the 3. The student should be able to list the
receptors and neurotransmitters of the ANS.receptors and neurotransmitters of the ANS.

4. The student should be able to list the 4. The student should be able to list the
sympathetic stress response.sympathetic stress response.

3. ANS OrganizationANS Organization

The ANS affects visceral function and The ANS affects visceral function and
chiropractic affects the ANS, therefore, chiropractic affects the ANS, therefore,
chiropractic affects visceral functionchiropractic affects visceral function

How then is the ANS organized?How then is the ANS organized?

A. HypothalamusA. Hypothalamus

B. Brain StemB. Brain Stem

C. Spinal CordC. Spinal Cord

D. Visceral ReflexesD. Visceral Reflexes

4. ANS OrganizationANS Organization

5. ANS OrganizationANS Organization

E. Sympathetic Nervous SystemE. Sympathetic Nervous System
–1. Paravertebral sympathetic chains of 1. Paravertebral sympathetic chains of
gangliaganglia
–2. Prevertebral ganglia2. Prevertebral ganglia

a. Celiaca. Celiac

b. Hypogastricb. Hypogastric
–3. T-1 to L-23. T-1 to L-2

6. ANS OrganizationANS Organization

F. Parasympathetic Nervous SystemF. Parasympathetic Nervous System

- Craniosacral Division- Craniosacral Division

G. Tissues Regulated - Involuntary OrgansG. Tissues Regulated - Involuntary Organs
–1. Visceral (Hollow) Organs1. Visceral (Hollow) Organs
–2. Exocrine Glands2. Exocrine Glands
–3. Endocrine glands3. Endocrine glands
–4. Blood Vessels4. Blood Vessels
–5. Heart5. Heart

7. ANS OrganizationANS Organization

H. Cell TypesH. Cell Types
–1. Smooth Muscle1. Smooth Muscle
–2. Cardiac Muscle2. Cardiac Muscle
–3. Gland Cells3. Gland Cells

I. FunctionsI. Functions
–1. Homeostatic conditions in the body1. Homeostatic conditions in the body
–2. Coordinating body response to stress2. Coordinating body response to stress
–3. Assist endocrine system reproduction3. Assist endocrine system reproduction

8. Sympathetic Nervous SystemSympathetic Nervous System

A. Thoracolumbar DivisionA. Thoracolumbar Division

B. Preganglionic Neuron - generally B. Preganglionic Neuron - generally
short axon in spinal columnshort axon in spinal column
–1. Cell body in intermediolateral horn1. Cell body in intermediolateral horn
–2. Fibers pass through anterior horn2. Fibers pass through anterior horn

9. Sympathetic Nervous SystemSympathetic Nervous System
–3. Synapse3. Synapse

a. In immediate ganglia (near a. In immediate ganglia (near
spinal cord)spinal cord)

b. Pass upward or downward to b. Pass upward or downward to
another gangliaanother ganglia

c. On organc. On organ

10. Sympathetic Nervous SystemSympathetic Nervous System
–4. 3 major central ganglia4. 3 major central ganglia

a. Celiac ganglia (solar a. Celiac ganglia (solar
plexus)plexus)

b. Superior mesenteric b. Superior mesenteric
gangliaganglia

c. Inferior mesenteric gangliac. Inferior mesenteric ganglia

11. Sympathetic Nervous SystemSympathetic Nervous System

C. Postganglionic NeuronC. Postganglionic Neuron
–1. Originate in the sympathetic 1. Originate in the sympathetic
chain ganglia or in one of the chain ganglia or in one of the
prevertebral gangliaprevertebral ganglia

12. Sympathetic Nervous SystemSympathetic Nervous System
–2. Destinations2. Destinations

a. Skeletal Nerves (about 8% are a. Skeletal Nerves (about 8% are
sympathetic)sympathetic)
–1. Blood vessels (some are 1. Blood vessels (some are
cholinergic)cholinergic)
–2. Sweat glands (cholinergic)2. Sweat glands (cholinergic)
–3. Piloerector muscles of the hairs 3. Piloerector muscles of the hairs
(cholinergic)(cholinergic)

13. Sympathetic Nervous SystemSympathetic Nervous System
b.b.Segmental distribution of sympathetic Segmental distribution of sympathetic
nerves – T1 and T2 head and neck, T3-T6 nerves – T1 and T2 head and neck, T3-T6
thorax, T7-T11 abdomen, T12-L2 legsthorax, T7-T11 abdomen, T12-L2 legs
c.c.c. Adrenal medullae c. Adrenal medullae
–1. Medullar secretes epinephrine and 1. Medullar secretes epinephrine and
norepinephrine into the blood streamnorepinephrine into the blood stream
–2. Fight or flight response2. Fight or flight response

a. Capable of firing all at once in a a. Capable of firing all at once in a
coordinated fashioncoordinated fashion

b. Generalized sympathetic responseb. Generalized sympathetic response

14. Sympathetic Nervous SystemSympathetic Nervous System

D. FunctionsD. Functions
–1. Emergency responses1. Emergency responses
–2. Utilization of resources 2. Utilization of resources
(Redistribution)(Redistribution)

16. Parasympathetic Nervous Parasympathetic Nervous
SystemSystem

A. Cranial-sacral DivisionA. Cranial-sacral Division
–1. Cranial nerves III, VII, IX, X1. Cranial nerves III, VII, IX, X
–2. 2nd & 3rd sacral spinal nerves 2. 2nd & 3rd sacral spinal nerves
(Sometimes 1st & 4th)(Sometimes 1st & 4th)

B. 75% are in the vagus nerve (X)B. 75% are in the vagus nerve (X)

C. Preganglionic fibers generally C. Preganglionic fibers generally
synapse at site of organsynapse at site of organ

17. Parasympathetic Nervous Parasympathetic Nervous
SystemSystem

D. Cholinergic-acetylcholine like actionsD. Cholinergic-acetylcholine like actions
–1. Restoration and buildup of body 1. Restoration and buildup of body
reservesreserves
–2. Elimination of waste2. Elimination of waste
–3. Digestion and absorption of food3. Digestion and absorption of food
–4. Rest and relaxation4. Rest and relaxation

18. NeurotransmittersNeurotransmitters

A. Acetylcholine (Parasympathetic A. Acetylcholine (Parasympathetic
nervous transmitter)nervous transmitter)
–1. Secreted by cholinergic fibers1. Secreted by cholinergic fibers
–2. All preganglionic neurons2. All preganglionic neurons
–3. All (almost) parasympathetic 3. All (almost) parasympathetic
postganglionic neurons (some release postganglionic neurons (some release
GABA a neural inhibitor)GABA a neural inhibitor)

19. NeurotransmittersNeurotransmitters

B. Norepinephrine (Sympathetic transmitter)B. Norepinephrine (Sympathetic transmitter)
–1. Secreted by adrenergic fibers1. Secreted by adrenergic fibers
–2. All postganglionic neurons except, 2. All postganglionic neurons except,
preganglionic fibers are cholinergic (Ach)preganglionic fibers are cholinergic (Ach)

a. Sweat glands (Ach)a. Sweat glands (Ach)

b. Piloerector muscle (Ach)b. Piloerector muscle (Ach)

c. Some blood vessels(Ach)c. Some blood vessels(Ach)

20. ReceptorsReceptors

A. Acetylcholine receptors (Ach is the A. Acetylcholine receptors (Ach is the
most prevalent neurotransmitter in the most prevalent neurotransmitter in the
peripheral nervous system)peripheral nervous system)
–1. Muscarinic Receptors1. Muscarinic Receptors

a. Activated by the fungus a. Activated by the fungus
muscarinemuscarine

b. Found in the effector cells b. Found in the effector cells

21. ReceptorsReceptors
–2. Nicotinic Receptors2. Nicotinic Receptors

a. Found in the synapse between a. Found in the synapse between
the preganglionic and the preganglionic and
postganglionic neurons of both the postganglionic neurons of both the
sympathetic and parasympathetic sympathetic and parasympathetic
systems and Skeletal muscle fiberssystems and Skeletal muscle fibers

22. ReceptorsReceptors

B. Adrenergic ReceptorsB. Adrenergic Receptors
–1. Alpha receptors1. Alpha receptors

a. Alpha1a. Alpha1

b. Alpha2b. Alpha2

c. Excited by Norepinephrine & c. Excited by Norepinephrine &
EpinephrineEpinephrine

23. ReceptorsReceptors
–2. Beta Receptors2. Beta Receptors

a. Beta1a. Beta1

b. Beta2b. Beta2

c. Excited primarily by epinephrinec. Excited primarily by epinephrine

24. Effects of Sympathetic & Effects of Sympathetic &
Parasympathetic StimulationParasympathetic Stimulation

SYM PSYMSYM PSYM

EyesEyesPupil dilationPupil dilation Pupil Constriction Pupil Constriction

GlandsGlandsIncreased Increased Increased nasal, Increased nasal,
Sweating Sweating salivary, and GI secretions salivary, and GI secretions

GIGIdecreaseddecreased Increased GI activity Increased GI activity
–
activityactivity

HeartHeart IncreasedIncreased decreased activity decreased activity
–
activityactivity

25. Stress Response - Stress Response -
Sympathetic Nervous SystemSympathetic Nervous System

A. Fight or flight responseA. Fight or flight response

B. Mass sympathetic dischargeB. Mass sympathetic discharge

C. Stimulation of adrenal medulla - C. Stimulation of adrenal medulla -
(epinephrine release)(epinephrine release)
–1. Catacholamine1. Catacholamine
–2. All effects have adrenergic receptors2. All effects have adrenergic receptors
–3. From adrenal medulla chromaffin cells3. From adrenal medulla chromaffin cells
–4. Enhances mobilization of glucose and fatty acids, blood 4. Enhances mobilization of glucose and fatty acids, blood
clotting and distribution, immune and tissue responses to clotting and distribution, immune and tissue responses to
injuryinjury

26. Stress Response - Stress Response -
Sympathetic Nervous SystemSympathetic Nervous System

D. ResponseD. Response
–1. Increased arterial pressure1. Increased arterial pressure
–2. Increased blood flow2. Increased blood flow
–3. Shunting of blood to active sites3. Shunting of blood to active sites
–4. Increased cell metabolism4. Increased cell metabolism
–5. Increased blood glucose concentration5. Increased blood glucose concentration
–6. Increased glycolysis in liver6. Increased glycolysis in liver
–7. Increased muscle strength7. Increased muscle strength
–8. Increased mental activity8. Increased mental activity
–9. Increased rate of blood coagulation9. Increased rate of blood coagulation