Spinal Cord Reflexes & Trauma

Vocabulary flashcards covering key terms related to spinal reflexes, reflex arc components, and spinal cord trauma.

Reflex

A quick, involuntary, stereotyped reaction of glands or muscles to sensory stimulation.

Somatic Reflex

A reflex involving the somatic nervous system that innervates skeletal muscle.

Reflex Arc

A neural pathway that produces a reflex action by acting on an impulse before it reaches the brain.

Somatic Receptor

A sensory receptor in skin, muscle, or tendon that detects stimuli for a reflex arc.

Afferent Nerve Fiber

The sensory neuron that carries information from receptors to the spinal cord or brainstem.

Integrating Center

A region of gray matter in the spinal cord or brainstem where incoming sensory information is processed and motor output is initiated.

Efferent Nerve Fiber

The motor neuron that carries impulses from the integrating center to effectors.

Effector

A muscle or gland that carries out the response in a reflex action.

Stretch (Myotatic) Reflex

A reflex in which a stretched muscle contracts to maintain posture and equilibrium.

Muscle Spindle

A stretch receptor embedded in skeletal muscle that initiates the stretch reflex.

Patellar (Knee-Jerk) Reflex

A monosynaptic stretch reflex elicited by tapping the patellar ligament, causing quadriceps contraction.

Monosynaptic Reflex

A reflex with only one central synapse between the sensory and motor neuron.

Polysynaptic Reflex

A reflex involving two or more central synapses.

Reciprocal Inhibition

A reflex mechanism that inhibits an antagonist muscle when the agonist is excited, preventing opposition.

Flexor (Withdrawal) Reflex

A quick contraction of flexor muscles to withdraw a limb from a harmful stimulus.

Polysynaptic Reflex Arc

A reflex pathway in which signals travel through multiple synapses en route to the effector.

Spinal Cord Trauma

Damage to the spinal cord, often from vertebral fractures, that can result in paralysis.

Complete Transection

Total severance of the spinal cord, causing loss of motor control below the injury.

Spinal Shock

Temporary paralysis and loss of reflexes following acute spinal cord injury.

Paraplegia

Paralysis of both lower limbs.

Quadriplegia

Paralysis of all four limbs.

Hemiplegia

Paralysis affecting one side of the body.

Paresis

Partial paralysis or muscular weakness of the limbs.