Overview of the Autonomic Nervous System Organization

Autonomic Nervous System

Controls involuntary bodily functions subconsciously.

Somatic Motor

Involves voluntary control of skeletal muscles.

Autonomic Motor

Involves involuntary control of organs and glands.

Preganglionic Neuron

First neuron in autonomic pathways, myelinated.

Postganglionic Neuron

Second neuron in autonomic pathways, unmyelinated.

Autonomic Ganglion

Synapse location between preganglionic and postganglionic neurons.

Acetylcholine (Ach)

Neurotransmitter released by preganglionic neurons.

Norepinephrine

Neurotransmitter released by sympathetic postganglionic neurons.

Epinephrine

Hormone released by adrenal medulla into bloodstream.

Alpha Receptors

Adrenergic receptors, two types: alpha 1 and alpha 2.

Beta Receptors

Adrenergic receptors, three types: beta 1, beta 2, beta 3.

Nicotinic Receptors

Bind acetylcholine at neuromuscular junctions.

Muscarinic Receptors

Bind acetylcholine on target organs.

Parasympathetic Branch

Promotes rest and digest functions.

Sympathetic Branch

Prepares body for fight or flight response.

Craniosacral

Origin of parasympathetic neurons from brain and sacral spinal cord.

Thoracolumbar

Origin of sympathetic neurons from thoracic and lumbar spinal cord.

Hypothalamus

Regulates autonomic nervous system functions.

Limbic System

Influences hypothalamus based on emotional states.

Frontal Lobe

Can influence hypothalamus and autonomic responses.

Chromaffin Cells

Specialized cells in adrenal medulla releasing epinephrine.

Target Tissue

Organs innervated by postganglionic neurons.

Ganglia

Clusters of neuronal cell bodies in autonomic pathways.