01/04 Lecture 17 - Neuroanatomy II

Graded potential

This is a localised change in the membrane potential caused by a typical stimulus

Action potential

This is a sufficiently large graded potential involved initially at once location on the excitable membrane that spreads across the axon toward the synaptic terminals

Upper motor neurons

Motor neurons that originate in the cerebral cortex and travel down to the spinal cord via the brain stem. Part of the efferent division of the SNS

Lower motor neurons

Motor neurons that originate in the spinal cord and travel to gland, muscles, and organs around the body. Part of the efferent division of the SNS

Visceral effector

This is an efferent nerve fibre that provides motor innervation to smooth muscle, cardiac muscle, and secretory glands

Innervation

This is the phenomena of a neuron providing contact to another neuron or to a gland, muscle, etc

Effector

This is a structure that nerves innervate with and control

Somatic efferent

This division refers to voluntary motor control

Somatic afferent

This division refers to sensory information we are aware of

Autonomic efferent

This division refers to involuntary motor control

Autonomic afferent

This division refers to sensory information we are not aware of

Preganglionic neurons

This describes visceral motor neurons with cell bodies in the brain stem and spinal cord

Ganglionic neurons

This describes visceral motor neurons that sit in peripheral ganglia and innervate visceral effectors

Autonomic ganglia

This describes ganglia that form the synapse between preganglionic and ganglionic (postganglionic) neurons

Gray horns

This describes areas of gray matter inside the spinal cord

Enteric nervous system (ENS)

This is the network of neurons and nerves in the walls of the digestive tract

Sympathetic chain ganglia

This describes ganglionic neurons that lie on both sides of the vertebral column, close to the CNS, and with long, unmyelinated axons that extend into the body

Collateral ganglia

This describes ganglionic neurons that innervate abdominopelvic tissues. Consists of celiac ganglia, superior mesenteric ganglia, inferior mesenteric ganglia

Adrenal medullae

This describes modified ganglionic neurons that secrete neurotransmitters and hormones directly into the bloodstream

Norepinephrine

This is a neurotransmitter and hormone that induces the sympathetic nervous system