Question

the increase in muscle tension that is produced by increasing the number of active motor units is called

incomplete tetanus.
treppe.
recruitment.
wave summation.
complete tetanus.

Explanation:

🆕 New Concept Discovered: Motor Unit Recruitment
Activating more motor units to increase muscle force.

Step 1: Understand the core question

The question asks for the term that describes an increase in muscle tension caused by increasing the number of active motor units. A motor unit consists of a single motor neuron and all the muscle fibers it stimulates.

Step 2: Analyze the options

• Incomplete tetanus: A state of sustained but wavering muscle contraction that occurs when a muscle is stimulated at a rapid rate, allowing only partial relaxation between stimuli. This is related to the frequency of stimulation, not the number of motor units.
• Treppe: Also known as the "staircase effect," this is the gradual increase in the strength of contraction observed when a muscle is stimulated repeatedly after a period of rest, primarily due to increased calcium availability in the sarcoplasm.
• Recruitment (Multiple motor unit summation): The process of increasing the number of active motor units to produce a stronger muscle contraction. When more force is needed, the nervous system activates ("recruits") additional motor units.
• Wave summation: This occurs when successive stimuli arrive before the muscle fiber has relaxed completely, causing the contractions to combine and produce more tension. This is a frequency-dependent mechanism within individual motor units.
• Complete tetanus: A smooth, sustained contraction without any relaxation phase, produced by very high-frequency stimulation.

Step 3: Match the definition to the correct term

Since the question specifically highlights increasing the number of active motor units to increase muscle tension, the correct physiological term is recruitment.

Answer:

recruitment.