• 1 handout today

• Exam #2 on Thursday• Bring scantron. Same format.

• You can pick up assignment #1 and written part of exam #1 outside my office in H510 – Health Science Building

PNS

CNS

Sensory Motor

ANS Somatic

SympatheticParasympathetic

Autonomic Nervous System• Visceral sensory & motor system

• Innervates viscera, smooth muscle, glands

• Autonomic = self governed

• Adjusts visceral functions to the body’s needs

• Responsible for visceral reflexes

High BP

DecreaseHeart rate

Somatic efferent innervation

Autonomic efferent innervation

ACh

ACh

ACh orNE

Autonomicganglion

ACh = Acetylcholine NE = Norepinephrine

Preganglionic 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

• Sympathetic– Speeds up– Fight or flight

• Parasympathetic– slows down– rest & digest

• Sympathetic division (thoracolumbar)– preganglionic cell in T1-

L2 of spinal cord

• Parasympathetic division (craniosacral)– preganglionic cell in S2-

S4 of spinal cord & 4 cranial nerves

– III, VII, IX & X

Locations of Ganglia

• Sympathetic ganglia– near spine– connected via chain

(sympathetic chain)– Short preganglionic neuron– Long postganglionic neuron

• Parasympathetic ganglia – in organ wall– not connected– Long preganglionic neuron– Short postganglionic neuron

Sympathetic ganglion

Communicatingrami

Dorsal ramus

Ventral ramus

Anterior (ventral)

Posterior (dorsal)

Fig. 14.12a(TE Art)

Communicating rami

Sympathetic chain

Fig. 16.3

Plexuses of ANS = sympathetic + parasympathetic

• Cardiac plexus

• Pulmonary plexus

• Celiac (solar) plexus

• Superior mesenteric

• Inferior mesenteric

• Hypogastric

Remember a stressful event

• What was that event

• List 5 changes that occurred in your body that you noticed during the event

Sympathetic pathways

Red = presynapticBlack = postsynaptic

Adrenalcortex

Adrenalmedulla

Cortex = steroid hormones (endocrine system)Medulla = modified sympathetic ganglion

• secretes epinephrine (adrenaline) & norepinephrine• innervated by preganglionic sympathetic neurons

Sympathetic pathways

• all this innervation is BILATERAL

• sympathetic pathways carry noxious sensory information (in general)

Parasympathetic pathways

Cranial nerves:III, VII, IX & X

Sacral nerves S2-S4

NT = acetylcholine

Also bilateral innervation

Carries most sensory info exceptnoxious stimuli

LowBP

Increase HR

sympathetic

High BP

CN IX CN IX

Decrease HR

CN X Vagus

Gut

stretch

peristalsis

vagus

vagus

BronchospasmIncreased gland activity

What is STRESS?

• Short term “amp”• Long term “amp”• Day after day• Year after year• Problems!

• Year after year

• Problems!- hypertension- ulcers- constipation- bladder infections- Raynaud’s- sexual dysfunction

Visceral 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

Sunday May 8th is Mother’s Day

Don’t forget your mom!!