Autonomic Nervous SystemEunice LeeDebora JeongJoshua Iannotti Period 4

Organization of Nervous System

Central Nervous System1. Brain

A) Forebrain (1) Sensory info (receive/process) (2) Thinking, perceiving, producing

B) Brainstem (1) Hindbrain

Balance equilibrium

(2) Midbrain Auditory and visual responses Motor functions

2. Spinal Cord A) connects brain to peripheral nervous system

Peripheral Nervous System1. Sensory Nervous System

A) sends info to CNS i.e. when someone pokes your finger

2. Motor Nervous SystemA) sends info from CNS i.e. when you want to lift your finger

B) Autonomic vs. Somatic (1) Somatic:

1. voluntary motor 2. skeletal muscles

(2) Autonomic: 1. involuntary motor 2. smooth and cardiac muscles 3. Parasympathetic vs. Sympathetic

Reflex Arc Definition: a neural pathway that controls a reflex

i.e. jolting backward when touching something hot

TWO types of Reflex Arc

1. Autonomic Reflex Affects inner organs (visceral= deep) Triggered by visceral afferent signaling Sensory neuron -> connecting neuron -> motor neuron

i.e. peristalsis, sweating

2. Somatic Reflex Affects muscles Starts with force acting onto a surface

i.e. hammer on patella

Then energy is received and sensory neuron senses force Then sends signal to motor neuron which sends a signal

to the brain to jerk the knee

Autonomic Somatic

Autonomic: Sympathetic vs Parasympathetic

Autonomic: Sympathetic vs Parasympathetic Body Part Sympathetic Parasympathetic

Eye Dilates Constricts

Heart Rate increases Rate decreases

Bladder Relaxes Contracts

Salivary Glands Stops production Increases production

Lungs Dilate bronchioles Constrict bronchioles

Liver Release glucose N/A

Adrenal Gland Secrete epinephrine/ norepinephrine

N/A

Intestines/ Stomach Decreases activities of muscles and glands

Increases gland secretions, motility

Kidney Vasoconstriction/ decreased urine output

N/A

Genitals Ejaculation Erection

Arrector pili Muscle Contract Relax

Gallbladder Relaxes Contracts

Ultimate Outcome for each System: Autonomic vs. Somatic

Autonomic: Maintaining homeostasis: Control glands Control smooth and cardiac muscle

Somatic:Self-Preservation: Control skeletal muscles

Ganglionic Fibers Axons sent into nerves Synapse with neurons

in ganglia first

PREGANGLIONIC FIBERS ARE…

POSTGANGLIONIC FIBERS ARE…

Sympathetic System

Preganglionic fibers- Reach spine and leave spine

(rami)- Synapse in sympathetic

ganglia- Shorter

Postganglionic fibers-Extend from sympathetic ganglia-Longer

Parasympathetic SystemPreganglionic fibers- Carried by vagus nerves- From brain and spinal chord

ganglia- Longer- Myelinated

Postganglionic fibers-Continue from ganglia organs-Shorter-Unmyelinated

Sympathetic Neurotransmitters

Preganglionic fibers secrete AcH (Acetylcholine)

Cholinergic

Postganglionic fibers secrete NE (Norepinephrine)

Andrenergic

Parasympathetic Neurotransmitters

Preganglionic fibers secrete AcH

Postganglionic fibers secrete AcH and Nitric Oxide

RECEPTORSNicotine AcH Receptor - Strong Muscle contractions- Both sympathetic and

parasympathetic

Adrenergic Receptors- Postganglionic neurons- Just sympathetic

Muscarinic AcH Receptors

- Receives AcH- Weak Muscle contractions- Just Parasympathetic

Termination of Receptors

AcHe (Acetylcholinesterase) breaks down AcH

NE is removed NE has prolonged effect

Bibliography https://

www.uic.edu/classes/pcol/pcol425/restricted/Guenthner/Pharm_PNS_new.pdf

http://faculty.stcc.edu/AandP/AP/AP2pages/Units14to17/unit14/ans.htm

http://www.ncbi.nlm.nih.gov/pubmed/7906875

http://www.ems1.com/medical-clinical/articles/893632-Receptors-and-the-autonomic-nervous-system/