Regulation and Integration of the Body

These flashcards cover the key vocabulary and definitions related to the regulation and integration of the body, specifically focusing on the spinal cord, its structure, functions, and related pathologies.

Dorsal Horn

The part of the spinal cord that contains interneurons receiving input from somatic and visceral sensory neurons.

Ventral Horn

The section of the spinal cord that contains motor neurons supplying skeletal muscles.

Dorsal Root Ganglion

An enlarged region of the dorsal root containing the cell bodies of sensory neurons.

Afferent Fibers

Nerve fibers carrying impulses from peripheral sensory receptors to the spinal cord.

Flaccid Paralysis

A type of paralysis occurring when the spinal cord or ventral roots are injured, causing muscles to be unable to move.

Spastic Paralysis

Paralysis resulting from damage to upper motor neurons, where spinal reflex activity continues to affect the muscles.

Decussation

The crossing over of nerve fibers from one side of the CNS to the other.

Somatotopy

The precise spatial relationship among the tract fibers in the central nervous system that reflects mapped areas of the body.

Ascending Pathways

Neuronal pathways that conduct sensory impulses to the brain, typically involving three successive neurons.

Direct Pathways

Motor pathways that originate from the pyramidal cells in the motor cortex and descend directly to the spinal cord.

Indirect Pathways

Motor pathways that involve multiple synapses and originate from various brainstem motor nuclei.

Spinothalamic Pathway

An ascending tract that transmits impulses for pain and temperature.

Dorsal Column-Medial Lemniscal Pathway

An ascending tract that mediates precise sensory input and discrimination from the body surface.

Poliomyelitis

A viral disease that destroys ventral horn motor neurons leading to paralysis and muscular atrophy.

Amyotrophic Lateral Sclerosis (ALS)

A progressive neurodegenerative disease that affects motor neurons and leads to loss of speech, swallowing, and breathing ability.

Pyramidal Tracts

Direct pathways that convey motor information from the cerebral cortex to the spinal cord.

Extrapyramidal Tracts

Motor pathways not originating from the pyramidal cells; involved in regulating balance and posture.