Autonomic Nervous System - created from Mind Map_1

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Functions

Visceral Motor Division of the PNS

Visceral functions: Heart rate, blood pressure, digestion, urination

Neuron Organization

Two Neuron Chain

Preganglionic autonomic motor neuron

Increases communication and control

Neuronal Convergence

Neuronal Divergence

Preganglionic Axon

Ganglionic autonomic motor neuron

Postganglionic Axon

mooth muscle, cardiac muscle, or glands

Divisions

Parasympathetic

Sympathetic

Function

Structure

conserving energy and replenishing nutrient stores

Rest and Digest

Maintain homeostasis

Discrete and localized effects

Craniosacral division

Neurons

Ganglion

Cranial Outflow

Sacral Outflow

Occulomotor

Facial

Glossopharyngeal

Vagus

Pupil constriction

increase production of tears, nasal secretions, and saliva

Increased saliva production

Abdominal Cavity

Thoracic Cavity

Increased smooth muscle contraction and secretory activity in digestive tract organs

Increased mucous production, decrease diameter in airways, decrease heart rate, decrease force of heart contractions

Pelvic splanchnic nerves

Axons run in ventral roots to ventral rami

Smooth muscle contraction, increased secretory activity in digestive organs (large intestine, rectum, urinary bladder, ureter), contracts bladder wall

Preganglionic Axons

Postganglionic Axons

Originate in the brainstem or lateral gray matter of the S2-S4 spinal cord segments

Have less than 4 branches

Long

Short

Terminal Ganglia

Intramural Ganglia

Close to target organ

Within walls of target organ

Function

Structure

Pathways

Fight or flight

Increase alertness and metabolic activity

Mass Activation

Supplies visceral organs and structures of superficial body regions

Increase heart rate, increase blood pressure, increase depth of respiration and breathing rate, dilate pupils

Ganglia

Neurons

Close to vertebral column

Sympathetic Trunk Ganglia

Prevertebral Ganglia

Sympathetic Trunk

Each sympathetic trunk ganglia is associated with each spinal nerve

house sympathetic ganglionic neuron cell bodies

White Rami Communicantes

Gray Rami Communicantes

Located on both sides of the vertebral column

carry preganglionic sympathetic axons from T1-L2 spinal nerves to sympathetic trunk

carry postganglionic sympathetic axons from the sympathetic trunk to the spinal nerves

Splanchnic nerves

composed of preganglionic sympathetic axons that do not synapse in a sympathetic trunk ganglion that extend anteriorly to most of the viscera

Occur only in abdomen and pelvis

Lie anterior to the vertebral column

Main Ganglia of the Splanchnic nerves

Celiac Ganglion

Superior mesenteric ganglion

Inferior mesenteric ganglion

inferior hypogastric ganglia

innervate stomach, spleen, liver, gallbladder, proximal part of duodenum, part of the pancreas

distal half of duodenum, part of the pancreas, remainder of small intestine, proximal part of large intestine, kidneys, and proximal parts of ureters

innervate distal colon, rectum, urinary bladder, distal parts of ureters, most of reproductive organs

Preganglionic Axons

Postganglionic Axons

All sympathetic preganglionic neurons originate in the lateral gray horns of the T1-L2 segments of the spinal cord

Short

20 Branches

Long, unmyelinated

Spinal nerve pathway

Postganglionic sympathetic nerve pathway

Splanchnic nerve pathway

Adrenal medulla pathway

receives preganglionic sympathetic axons

Major organ of the sympathetic nervous system

Constitutes largest sympathetic ganglia

The cells within the adrenal medulla that synapse with the axons release hormones that circulate in the blood stream to help prolong the “fight or flight” response

Epinephrine and Norepinephrine

Autonomic Plexus

Collections of sympathetic postganglionic axons and parasympathetic preganglionic axons as well as some visceral sensory axons

Cardiac Plexus

Pulmonary Plexus

Hypogastirc Plexus

Esophageal plexus

Abdominal aortic plexus

Composed of postganglionic sympathetic axons that extent from the cervical and thoracic sympathetic trunk ganglia and preganglionic axons from the vagus nerve

In Thoracic Cavity

Controls heart rate and blood pressure

Composed of postganglionic sympathetic axons from the thoracic sympathetic trunk ganglia and preganglionic axons from the vagus nerve

Controls the diameter of the bronchi and secretion from mucous glands of the bronchial tree

Composed of a complex meshwork of postganglionic sympathetic axons and preganglopnic parasympathetic axons from the pelvic splanchnic nerve

Innervate viscera within the pelvic region

Composed of preganglionic axons from the vagus nerve

Controls cardiac sphincter and swallowing reflex

Celiac plexus, superior mesenteric plexus, inferior mesenteric plexus

Composed of postganglionic axons projecting from the pre vertebral ganglia and preganglionic axons from the vagus nerve that enter the abdominopelvic cavity with the esophagus

Neurotransmitters

a compound released at the synapse

Neurotransmitter only acts on receptors specific to that molecule

generally much faster than the endocrine transmission.

Acetylcholine (ACh)

Norepinerphrine (NE)

Epinephrine (EPI)

Neurotransmitter in PNS and SNS

released by all preganglionic axons and binds to specific receptors in the ganglionic plasma membrane and has an excitatory effect on the ganglionic cell

a nerve that releases ACh as its neurotransmitter is called a cholinergic nerve

neurotransmitter unique to the SNS

can have an excitatory or inhibitory effect on the effector, depending on the receptor on the effector plasma membrane

made in, released from all postganglionic sympathetic nerves when the SNS is activated

a nerve that releases NE is called an adrenergic nerve

Hormone unique to SNS

Adrenaline

Made in, released from cells of the adrenal medulla

Dual Innervation

visceral effectors are innervated by postganglionic axons from both ANS divisions and the actions are antagonistic to each other

Autonomic Reflexes

smooth muscle contractions, cardiac muscle contractions, or secretion by glands that are mediated by autonomic reflex arcs in response to a specific stimulus

CNS Control of ANS

Cerebrum

Hypothalmus

Amygdala

Brain Stem

Spinal Cord

Conscious activities in the cerebrum affect hypothalamus control of ANS

ntegration and command center for autonomic functions; involved in emotions

Main limbic center for emotions

Contains major ANS reflex centers

Contains ANS reflex centers for defecation and urination

Autonomic Nervous System