Neurobiology - Lecture 1 Module 1

CNS neuron

a neuron whose cell body is in the brain or spinal cord

PNS neuron

a neuron whose cell body is outside of the brain and of the spinal cord

Afferent

a neuron that transmits information from the body to the brain or the spinal cord (ascending pathway)

Efferent

a neuron that transmits information from the brain and spinal cord to the rest of the body (descending pathway)

Motor neuron

transmits commands from the brain to the skeletal muscles to mediate voluntary movement, always stimulates target muscle (somatic motor system)

Sensory neuron

transmits sensory signals from the body to the spinal cord or brain

Autonomic neuron

a neuron that transmits commands from the CNS to the smooth muscles of the organ/gland, or to the cardiac muscle of the heart to mediate involuntary autonomic responses

Association neuron

a CNS neuron that relays information from the sensory neuron to the motor neuron or the brain, also known as interneuron

Ganglion

a cluster of neuronal cell bodies outside of the brain and of the spinal cord

Sympathetic

a 2-neuron chain autonomic system that prepares the body for high activity state, such as flight-and-flight situation

Parasympathetic

a 2-neuron chain autonomic system that prepares the body for low activity state, such as during eating

Preganglionic

the first neuron in the 2-neuron chain of the autonomic neural circuit | sympathetic : short preganglionic neurons secrete acetylcholine | parasympathetic : long preganglionic that secrete acetylcholine

Postganglionic

the first neuron in the 2-neuron chain of the autonomic neural circuit | sympathetic : long postganglionic neurons that secrete mostly norepinephrine | parasympathetic : short postganglionic neurons that secrete acetylcholine

Dermatome

a skin area innervated by a spinal nerve, a spinal nerve is composed of a mixture of sensory, autonomic and motor neurons

Myotome

a group of muscles innervated by a spinal nerve