Autonomic Nervous System

Supraspinal centers

• centers in the hypothalamus and brainstem that regulates ANS reflexes

Brain or spinal cord

• Where is the cell body of a preganglionic neuron located

Type B fiber

• What type of neuron does a preganglionic neuron have?

• Small-diameter, myelinated

Autonomic ganglion

• the site of synapse of the autonomic pathway

In the ganglion

• where is the cell body of a Postganglionic neuron located

Type C

• what type of neuron is the axon of a Postganglionic neuron

Sympathetic nervous system

• supports exercises or emergency actions

• Fight or flight responses

Lateral horns of gray matter of T1-L2

• where are the preganglionic neuron cell bodies of the SNS located?

White ramus communicans

Structures containing sympathetic preganglionic axons

Sympathetic trunk ganglia

sites of synapses betwen preganglionic and postganglionic neurons

superior cervical ganglion

• cervical portion of the sympathetic trunk ganglia that supplies the head and heart

Middle and inferior cervical ganglion

• cervical portion of the sympathetic trunk ganglia that supplies the heart

Thoracic sympathetic trunk

• Portion of the sympathetic trunk ganglia that supplies the thoracic viscera, sweat glands, blood vessels, and arrector pili muscles

Gray ramus communicans

structures containing sympathetic post ganglionic axons

Greater splanchnic nerve

• arises from lower thoracic segment (T5-T9/T10)

Lumbar splanchnic nerve

• arises from upper lumbar segements (L1-L4)

Parasympathetic nervous system

• For conserving and storing energy

• Rest and digest

Nuclei of CN 3, 7, 9, 10 and Lateral gray matter of S2-S4

• preganglionic neurons cell bodies of the PNS is located at:

Edinger-Westphal nucleus

• nucleus of CN 3

Superior salivatory nuclei

• nucleus of CN 7

Inferior salivatory nuclei

• nucleus of CN 9

Dorsal nucleus

• nucleus of CN 10

Short Preganglionic, Long postganglionic

neuronal length of SNS

long preganglionic, short post ganglionic

neuronal length of PNS

Autonomic plexus

• large network of nerves that serves as a conduit of sympathetic and parasympathetic fibers into their formation

• Collecgtion of SNS and PNS efferent fibers, ganglia, and afferent fibers

Cardiac Plexus

• location: bifurcation of the trachea, base of heart

• Formed by cardiac sympathetic nerves and vagus nerve

• Distributes to the myocardium and vessels leaving the heart

Pulmonary plexus

• location: primary bronchi, pulmonary arteries

• Formed by: vagius nerve, upper thoracic sympathetic nerves

• Distributes to vessels and bronchi of the lung

Celiac Plexus

• largest autonomic plexus

• Location: epigastric region over abdominal aorta

• Formed by: vagal fibers, sympathetic fibers from thoracic aortic plexus

• Distributes to most of the abdominal viscera

Hypogastric plexus

• location: in front of L5 and sacral promontory

• Formed by: sympathetic fibers from aortic plexus and lumbar trunk ganglia, parasymoathetic fibers from pelvic nerve

• Distributes to pelvic visceral, urinary bladder, and genitals

Enteric nervous system

• intrinsic nervous system of the gastrointestinal tract

• Innervates: smooth muscles for gut motility, secretory and endocrine cells into their formation gut and vessels

• Regulates: gastrointestinal motility, secretory activity, vascular activity, inflammation

Myenteric plexus

• location: muscles making up the gastrointestinal system

• Also associated with pancreas and gallbladder

Submucosa Plexus

• submucosa of the gut

• Prominent within the small intestine

• Regulates secretory activity and innervates blood vessels

Cholinergic

• Preganglionic neurons

• PNS postganglionic neurons

• Sweat glands or vasodilators of skeletal muscles

Adrenergic

• SNS postganglionic neurons

• Secreted by adrenal medulla

Alpha 1

• location: arteries

• Function: increase BP and blood flow returning to heart

Alpha 2

• location: brain and periphery

• Funstion: decrease neurotransmitter release, and promote vasodilation

Beta 1

• Location: Heart

• function: increase heart rate and heart’s contractility

Beta 2

• Location: Bronchioles of the lungs and arteries of skeletal muscles

  • Function: increase diameter of bronchioles, dilate vessels of skeletal muscles

Nicotinic

• Location: chromaffin cells and sarcolemma

• Function: epinephrine and norepinephrine secretion, muscle contraction

Muscarinic

• location: sweat glands and skeletal muscle blood vessels

• Function: increase sweat and vasodilates skeletal blood vessels

Hypothalamus

• main control and integration

• Receives sensory input

• Influence autonomic center in brain and spinal chord