PHYSL 212 Lecture 13: Autonomic Nervous System (Terms)

Somatic Sensory Nervous System

The division of the afferent peripheral nervous system responsible for sensation of body awareness, temperature, pain, and other bodily touch

Visceral Sensory Nervous System

The division of the afferent peripheral nervous system responsible for sensation of visceral reflex indicators, such as hunger

Cervical Nerves

The 8 spinal nerves located in the cervical region that innervate shoulders and above as well as arms and hands

Thoracic Nerves

The 12 spinal nerves located in the thoracic region that innervate chest and upper abdomen

Lumbar Nerves

The 5 spinal nerves located in the lumbar region that innervate lower abdomen and legs

Sacral Nerves

The 5 spinal nerves located in the sacral region that innervate genitals and lower digestive tract

Coccygeal Nerve

The single spinal nerve located in the coccygeal region that innervates the tailbone and rectum

Preganglionic Fibre

The neuron axon fibre that will synapse at the ganglion in sensory autonomic pathways, being the first of two neurons before reaching the effector

Postganglionic Fibre

The neuron axon fibre that will receive a signal at the ganglion in sensory autonomic pathways and synapse at the effector

Thoracolumbar System

The neuron pathways located in T1-T12 and L1-L2 that correspond to the nerves innervating sympathetic nervous functions

Sympathetic Trunk (Paravertebral Chain)

Paired chain of interconnected sympathetic ganglia that lie on either side of the vertebral column

Collateral Ganglia

Unpaired cell body clusters in front of the vertebral column that innervate large, general abdominal regions

Splanchnic Nerve

Spinal nerve axon fibres that do not synapse at the thoracolumbar ganglia, but instead move out and synapse at the collateral nerves instead

Communicating Rami

Two spinal root branches that connect a paravertebral ganglion to a spinal nerve

White Rami

A communicating ramus that carries a myelinated preganglionic fibre out of the spinal nerve to synapse at a sympathetic ganglion

Grey Rami

A communicating ramus that carries an unmyelinated postganglionic fibre that has received a synapse signal out of the sympathetic ganglion to re-enter the spinal nerve

Craniosacral System

The neuron pathways located in cranial nerves 3, 7, 9, 10 and S2-S4 that correspond to the nerves innervating parasympathetic nervous functions

Terminal Ganglion

A parasympathetic ganglion situated closely to an innervated organ, which is where presynaptic parasympathetic fibres synapse

Dual Autonomic Innervation

The innervation of certain body parts via both the sympathetic and parasympathetic nervous system

Autonomic Tone

Dual autonomic innervation in which background activity (activation) of the organ is maintained by both parasympathetic and sympathetic divisions, with priority shifting between each system when needed

Reciprocal Activation

Dual autonomic innervation in activity of the organ is increased by one system and decreased by another, where sympathetic would dominate during fight or flight and parasympathetic would dominate during rest and digest

Antagonistic Effects

Effects of dual autonomic innervation on an organ system in which each division contributes to a different reaction of an organ system (ex. GI increased by para, decreased by sympa)

Cooperative Effects

Effects of dual autonomic innervation on an organ system in which both divisions contribute to the same reaction of an organ system, to a differing degree (ex. saliva produced by both sympathetic and parasympathetic, but different types)

Chloinergic Fibres

Nerve fibres that release the neurotransmitter acetylcholine across the synapse

Adenergic Fibres

Nerve fibres that release the neurotransmitter epinepherine/norepinepherine across the synapse

Cholinergic Receptor

Any receptor that binds to acetylcholine on the postsynaptic membrane

Varicosity

Chains of swellings along the branches of a postganglionic fibre, containing synaptic vesicles that release neurotransmitter

Nicotinic Receptors

Cholinergic receptors found in skeletal muscle and all autonomic ganglia that are ionotropic channels for sodium and potassium, causing depolarization

Muscarinic Receptors

Cholinergic receptors found in effector ANS cell membranes that are metabotropic, activating G-protein coupled mechanisms

Adrenergic Receptors

Metabotropic receptors found in effector ANS cell membranes that bind E/NE, activating G-protein coupled mechanisms

Convergence

The phenomenon where multiple presynaptic neurons form synapses with a single postsynaptic neuron, coming together to form a specialized or specific response

Divergence

The phenomenon where one presynaptic neuron form synapses with mutliple postsynaptic neurons, spreading out to form a mass discharge response