BIOL 252 Lab 1: Spinal Cord and Nerves Vocabulary

Vocabulary flashcards covering key terms, anatomical planes, meninges, spinal cord grey/white matter divisions, nerve rami, plexuses, tracts, and reflex arcs from BIOL 252 Lab 1.

Transverse Plane

An anatomical plane that divides the body into superior and inferior parts.

Frontal/Coronal Plane

An anatomical plane that divides the body into anterior and posterior parts.

Sagittal Plane

An anatomical plane that divides the body into right and left parts.

Midsaggital

An anatomical plane located directly in the middle of the body.

Conus Medullaris

The terminal end of the spinal cord located around the L1/L2 vertebra.

Cauda Equina

The bundle of spinal nerves (L2 and lower) formed below the conus medullaris.

Denticulate Ligaments

Specializations of the pia mater that secure and stabilize the spinal cord in the spinal column.

Dermatomes

Specific regions of the body innervated by spinal nerves.

Epidural Space

A fat-filled protective space located superficial to the dura mater.

Dura Mater

The outermost and toughest layer of the meninges.

Subarachnoid Space

The meningeal space located beneath the arachnoid mater that is filled with CSF (cerebrospinal fluid).

Pia Mater

The innermost layer of the meninges that is tightly adhered to the spinal cord.

White Matter

Spinal cord tissue containing myelinated axons.

Tract

A bundle of neurons within the spinal cord white matter sharing a related function.

Dorsal Horn

The grey matter region of the spinal cord that receives all incoming sensory information.

Lateral Horn

The grey matter region containing cell bodies of visceral motor neurons that send signals to glands and smooth/cardiac muscles.

Ventral Horn

The grey matter region containing cell bodies of somatic motor neurons that send signals out of the spinal cord to skeletal muscles.

Dorsal Root

The nerve root that carries all sensory information toward the spinal cord, identified by its dorsal root ganglion.

Dorsal Root Ganglion

A bulge located on the dorsal root created by a clump of sensory neuron cell bodies.

Ventral Root

The nerve root that carries all motor information away from the spinal cord.

Dorsal Ramus

A branch of the spinal nerve conveying sensory and motor information to and from the back of the torso/body.

Ventral Ramus

The largest spinal nerve branch, conveying sensory and motor information to and from the front of the torso/body and the limbs.

Communicating Rami

Branches of the spinal nerve that convey sensory and motor information to and from visceral organs.

Cervical Plexus

A nerve network formed by ventral rami that innervates neck muscles.

Brachial Plexus

A nerve network formed by ventral rami that innervates the upper appendages.

Lumbosacral Plexus

A nerve network formed by ventral rami that innervates the lower appendages.

Intercostal Nerves

Nerves running along the ribs that innervate the muscles and skin of the abdominal wall.

Decussation

The crossing over of a neuron to the opposite side of the spinal cord.

Spinothalamic Tract

An ascending 3-neuron sensory pathway that carries non-localized sensations (e.g., pain/temperature) from the body to the brain and decussates at the spinal cord level of sensation.

Corticospinal Tract

A descending 2-neuron motor pathway that brings motor information from the brain to the lateral or ventral horn, decussating at the medullary pyramids of the medulla oblongata.

Monosynaptic Reflex

A reflex arc where a sensory neuron synapses directly with a motor neuron in the ventral horn without any interneurons (e.g., the patellar knee-jerk reflex).

Polysynaptic Reflex

A reflex arc where a sensory neuron synapses with one or more interneurons in the dorsal horn before synapsing with a motor neuron (e.g., the withdrawal reflex).