Spinal Cord and Sensory Pathways

Flashcards covering key terms and concepts related to the structure and function of the spinal cord and sensory pathways.

Gray Matter

The area of the spinal cord containing neuron cell bodies, organized into horns.

White Matter

The area of the spinal cord composed of myelinated axons organized into columns.

Dorsal Root Ganglion (DRG)

A cluster of sensory neuron cell bodies located outside the spinal cord.

Decussation

The crossing of nerve fibers from one side of the central nervous system to the other.

First Order Neuron

The neuron that first receives sensory information and is located in the dorsal root ganglion.

Second Order Neuron

The neuron that transmits sensory information from the spinal cord or brainstem to the thalamus.

Third Order Neuron

The neuron that relays sensory information from the thalamus to the cerebral cortex.

Medial Lemniscal Pathway

A sensory pathway responsible for transmitting proprioception and fine touch.

Spinothalamic Pathway

A sensory pathway responsible for transmitting pain, temperature, and crude touch.

Corticospinal Pathway

A major motor pathway that controls voluntary motor functions.

Pyramidal System

The pathway involving upper motor neurons in the cortex and lower motor neurons in the brainstem or spinal cord.

Extrapyramidal System

The pathway that modulates involuntary control of muscular tone and posture.

Sensory Pathways

Nerve pathways that transmit sensory information from receptors to the brain.

Motor Pathways

Nerve pathways that convey motor commands from the brain to the muscles.

Cortex

The outermost layer of the brain, involved in higher-level functions such as perception and voluntary movement.

Thalamus

A relay station in the brain that processes and transmits sensory information to the cortex.