1. Somatic efferent innervation Visceral efferent innervation
ACh = Acetylcholine
NE = Norepinephrine
Somatic efferent innervation
ACh
Visceral efferent innervation
ACh or NE
ACh
Note that brain connection is missing here!
Autonomic
ganglion

2. Autonomic Nervous System
basic anatomy of ANS
ANS vs PNS
divisions of ANS
sympathetic division
anatomy & function
ANS plexuses
sympathetic response
adrenal gland
parasympathetic division
visceral reflexes
stress & the ANS
referred pain anatomy

3. CNS PNS Sensory Motor Visceral Somatic Parasympathetic Sympathetic
Somatic & visceral
Motor
Visceral
Somatic
Parasympathetic
Sympathetic

4. Autonomic Nervous System
Visceral sensory & motor system
Innervates viscera, smooth muscle and glands
Autonomic = self governed
Adjusts visceral functions to the body’s needs
Responsible for visceral reflexes
CN IX
High BP
CN X
What is “visceral sensory” info?? examples
Decrease
Heart rate

5. Basic anatomy of ANS Preganglionic neuron Postganglionic neuron
cell body in brain or spinal cord (lateral horn)
axon is myelinated
Synapses in ganglion
Postganglionic neuron
cell body in autonomic ganglion
axon is unmyelinated
synapses on visceral effector

6. Sympathetic Parasympathetic Speeds up Fight or flight slows down
rest & digest

7. Sympathetic division (thoracolumbar)
preganglionic neuron cell body in T1-L2 of spinal cord
Ganglia near spine
connected by a chain
(sympathetic chain)
Short preganglionic neuron
Long postganglionic neuron
Parasympathetic division (craniosacral)
preganglionic neuron cell body in S2-S4 of spinal cord & brainstem
CN’s III, VII, IX & X
Ganglia in organ wall
Ganglia are not connected
Long preganglionic neuron
Short postganglionic neuron

8. Anatomy of sympathetic chain
Posterior (dorsal)
Dorsal ramus
Communicating
rami
Ventral ramus
Sympathetic
ganglion
Anterior (ventral)

9. Sympathetic chain in thorax

10. Sympathetic innervation of the heart
brain
Lateral horn

11. Sympathetic pathways BILATERAL (right & left) sympathetic pathways
all this innervation is
BILATERAL (right & left)
sympathetic pathways
innervate sweat gland, arrector
pili & smooth muscle of blood
vessels peripherally
organ responses?
carry noxious sensory
information (except in pelvis)

12. Adrenal gland Adrenal cortex Adrenal medulla
Cortex = steroid hormones (endocrine system)
Medulla = modified sympathetic ganglion
secretes epinephrine (adrenaline) & norepinephrine
innervated by preganglionic sympathetic neurons
products get secreted into bloodstream

13. Parasympathetic pathways
Cranial nerves: III, VII, IX & X
Sacral nerves S2-S4
NT = acetylcholine
Also bilateral innervation
Carries most sensory info except
noxious stimuli

14. Plexuses of ANS sympathetic + parasympathetic
Cardiac plexus
Pulmonary plexus
Celiac (solar) plexus
Superior mesenteric
Inferior mesenteric
Hypogastric

16. Visceral reflex CN IX CN IX Low BP High BP sympathetic CN X Vagus
Increase HR
And constrict BV
Decrease HR
And dilate BV
Beta adrenergic blockers
Block sympathetic response

17. parasympathetic response bronchospasm increased gland activity
vagus
vagus
Asthma
parasympathetic response
bronchospasm
increased gland activity
treat with B2 adrenergic agonists
(stimulate sympathetic response)
Phenylephrine vs pseudoephedrine

18. T1-T4 receive visceral afferents from heart
T1 dermatome
Sensory from skin = green
Sensory from heart = red

19. Referred Pain
Organ & skin pain fibers travel to the spinal cord together
Organ pain misinterpreted as skin pain (referred pain)
Heart & skin in left arm = spinal nerves T1-T5
Heart attack (pain) is felt in skin (pain) along left arm & chest

20. What is STRESS? Short term “amp” to long term amp Year after year……
Problems!
- hypertension
- ulcers
- constipation
- bladder infections
- Raynaud’s
- sexual dysfunction