Definition

1. Noun:
   • An automatic muscle contraction in response to stretching: The "stretch reflex" is an involuntary, rapid contraction of a muscle that occurs when its tendon is pulled or the muscle itself is stretched. This reflex is a fundamental mechanism for maintaining posture and stability.

Usage

• The "stretch reflex" is a specific, scientific term used primarily in physiology, medicine, and biology.
• It describes an automatic, protective, and postural function of the nervous system.
• It is often tested by a doctor tapping a tendon with a reflex hammer.

Examples

• Noun:
  • The doctor tested the patient's patellar tendon to check the knee-jerk stretch reflex.
  • A strong stretch reflex in the leg muscles is crucial for maintaining erect posture while standing.
  • When the muscle spindle senses a rapid stretch, it triggers the stretch reflex.

Advanced Usage

• "to elicit a stretch reflex": to cause the reflex to happen, typically through a tap or quick stretch.
  • The physician used a hammer to elicit a stretch reflex from the Achilles tendon.
• "hyperactive stretch reflex": a reflex that is stronger or more easily triggered than normal, often indicating a neurological condition.
  • Hyperactive stretch reflexes are a common sign in patients with upper motor neuron lesions.

Variants and Related Words

• Myotatic reflex (n): Another, more technical name for the stretch reflex.
  • The monosynaptic pathway is the basis of the myotatic reflex.
• Deep tendon reflex (DTR) (n): A clinical term often used synonymously with stretch reflex, as the test involves tapping a tendon.
  • The biceps and triceps deep tendon reflexes were normal.

Synonyms

• Myotatic reflex: The precise physiological synonym.
• Deep tendon reflex (DTR): The common clinical synonym.

Related Phrases

• Monosynaptic reflex arc: The simple neural pathway (involving only one synapse between sensory and motor neurons) that mediates the stretch reflex.
  • The stretch reflex is a classic example of a monosynaptic reflex arc.
• Muscle spindle: The sensory receptor organ within the muscle that detects stretch and initiates the reflex.
  • The signal from the muscle spindle travels to the spinal cord to generate the stretch reflex.

Noun

1. reflex contraction of a muscle when an attached tendon is pulled; important in maintaining erect posture