Spinal Cord Injury, Motor Neurons, and Reflexes

Motor Cortex

The area of the brain that controls voluntary muscle movements, with a mapped representation of different body parts.

Upper Motor Neuron

The neuron that carries signals from the motor cortex to the spinal cord, responsible for initiating movement.

Lower Motor Neuron

The neuron that exits the spinal cord to send signals to muscles, directly causing contraction.

Reflex Arc

The neural pathways that mediate reflex actions, allowing for quick responses to stimuli.

Patellar Tendon Reflex

A reflex that occurs when the tendon below the kneecap is tapped, causing the quadriceps to contract.

Hyperreflexia

Exaggerated reflex response resulting from upper motor neuron damage, as inhibition is lost.

Spasticity

Increased muscle tone or stiffness, often resulting from upper motor neuron damage.

Hyporeflexia

Reduced reflex response that occurs when the lower motor neuron is damaged.

Flaccidity

Lack of muscle tone, observed in lower motor neuron damage where the muscle does not contract.

Neural Growth Factors

Substances released by neurons that promote muscle maintenance and growth.