Spinal Cord Anatomy and Reflexes

A collection of vocabulary flashcards covering key concepts related to spinal cord anatomy, functions, reflex arcs, and related structures.

Spinal Cord

The part of the central nervous system that arises from the brainstem, passes through the vertebral canal, and provides innervation to the body through spinal nerves.

Cervical Enlargement

Thickened region of the spinal cord that provides innervation to the upper limbs, located between C3 and T1.

Lumbar Enlargement

Thickened region of the spinal cord that provides innervation to the pelvic region and lower limbs, located between T12 and L1.

Filum Terminale

A fibrous tissue that supports and anchors the spinal cord to the coccyx.

Anterior Median Fissure

A deep central groove on the front of the spinal cord that incompletely divides it into two symmetrical halves.

Posterior Median Sulcus

A shallow groove on the back of the spinal cord that divides it into right and left halves.

Gray Matter

The region in the spinal cord composed of cell bodies, dendrites, and proximal parts of axons, organized into horns.

White Matter

The region in the spinal cord composed of axon bundles that transmit information between the brain and the body.

Ascending Tracts

Nerve pathways in the spinal cord that carry sensory information from the body to the brain.

Descending Tracts

Nerve pathways in the spinal cord that carry motor commands from the brain to the body.

Reflex Arc

The pathway that a reflex impulse follows, typically consisting of a receptor, sensory neuron, integration center, motor neuron, and effector.

Monosynaptic Reflex

A reflex that involves a direct connection between a sensory neuron and a motor neuron.

Polysynaptic Reflex

A reflex that involves one or more interneurons between the sensory neuron and motor neuron.

Dermatomes

Areas of skin innervated by sensory fibers of a single spinal nerve root.

Corticospinal Pathway

A motor pathway that carries signals from the cerebral cortex to the spinal cord, allowing for voluntary motor control.

Tendon Reflex

A reflex that prevents excessive tension on a tendon, causing sudden relaxation of the contracting muscle.

Flexor Reflex

A rapid contraction of flexor muscles to withdraw a limb from a painful stimulus.

Cauda Equina

A collection of spinal nerves and nerve rootlets below the end of the spinal cord, resembling a horse's tail.

Nerve Plexus

A network of nerves formed by the fusion of various spinal nerves that provides innervation to a specific body region.

Gray Commissure

A region of gray matter that connects the left and right sides of the spinal cord.

Lateral Gray Horns

Regions of gray matter in the spinal cord that contain visceral motor neurons.

Dura Mater

The outermost layer of the meninges, providing protection for the spinal cord.

Arachnoid Mater

The middle layer of the meninges, which covers the spinal cord and contains the cerebrospinal fluid in the subarachnoid space.

Pia Mater

The innermost layer of the meninges that directly adheres to the surface of the spinal cord.