The Spinal Cord, Spinal Nerves, and Somatic Reflexes

These flashcards cover key concepts related to the anatomy and function of the spinal cord, spinal nerves, and somatic reflexes as outlined in the lecture notes.

Conduction

Nerve fibers conduct sensory and motor information up and down the spinal cord.

Neural integration

Spinal neurons receive input from multiple sources, integrate it, and execute appropriate output.

Locomotion

The spinal cord contains central pattern generators that coordinate repetitive sequences of contractions for walking.

Reflexes

Involuntary responses to stimuli that are vital to posture, coordination, and protection.

Spinal cord anatomy

A cylinder of nervous tissue that arises from the brainstem and occupies the upper two-thirds of the vertebral canal.

Dura mater

The tough, thick outer layer of the meninges that forms a sleeve around the spinal cord.

Arachnoid mater

The middle layer of the meninges that is adherent to the dura and separated from the pia by the subarachnoid space.

Pia mater

The delicate inner layer of the meninges that follows the contours of the spinal cord.

Gray matter

Dull in color (no myelin); contains neuron cell bodies, dendrites, and proximal portions of axons.

White matter

Bright, pearly white due to myelin; consists of axon bundles coursing up and down the cord.

Ascending tracts

Tracts that carry sensory information up to the brain.

Descending tracts

Tracts that carry motor information down from the brain.

Decussation

The crossing of tracts at the midline, allowing the brain to sense and control the contralateral side of the body.

Dermatome

A specific area of skin that conveys sensory input to a spinal nerve.

Reflex arc

The pathway followed during a reflex, including receptors, afferent nerves, integrating centers, efferent nerves, and effectors.

Monosynaptic reflex

A reflex involving one synapse between the afferent and efferent neurons.

Polysynaptic reflex

A reflex that involves one or more interneurons.

Pain signals via spinothalamic tract

Signals for pain, pressure, light touch, and related sensations that decussate to the contralateral side.