MEDICAL PHYSIOLOGY

Detailed explanation-1: -This phenomenon is called wave summation. Eventually the frequency of action potentials would be so high that there would be no time for the muscle to relax between the successive stimuli and it would remain totally contracted, a condition called tetanus.

Detailed explanation-2: -Summation and Tetanus Contractions: Repeated twitch contractions, where the previous twitch has not relaxed completely are called a summation. If the frequency of these contractions increases to the point where maximum tension is generated and no relaxation is observed then the contraction is termed a tetanus.

Detailed explanation-3: -Definition. A single uterine contraction lasting greater than 2 minutes. [ from NCI]

Detailed explanation-4: -A muscle twitch has a latent period, a contraction phase, and a relaxation phase. A graded muscle response allows variation in muscle tension. Summation occurs as successive stimuli are added together to produce a stronger muscle contraction. Tetanus is the fusion of contractions to produce a continuous contraction.

Detailed explanation-5: -Tetanic contraction is usually normal (such as when holding up a heavy box). Muscles often exhibit some level of tetanic activity, leading to muscle tone, in order to maintain posture; for example, in a crouching position, some muscles require sustained contraction to hold the position.