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Fused tetanus is when there is no relaxation of the muscle fibers between stimuli and it occurs during a high rate of stimulation. [5] A fused tetanic contraction is the strongest single-unit twitch in contraction. [6] When tetanized, the contracting tension in the muscle remains constant in a steady state. This is the maximal possible ...
The contraction produced can be described as a twitch, summation, or tetanus, depending on the frequency of action potentials. In skeletal muscles, muscle tension is at its greatest when the muscle is stretched to an intermediate length as described by the length-tension relationship.
Summation, which includes both spatial summation and temporal summation, is the process that determines whether or not an action potential will be generated by the combined effects of excitatory and inhibitory signals, both from multiple simultaneous inputs (spatial summation), and from repeated inputs (temporal summation).
Also, tetany can be demonstrated by tapping anterior to the ear, at the emergence of the facial nerve. A resultant twitch of the nose or lips suggests low calcium levels. This is now known as the Chvostek sign. [citation needed] EMG studies reveal single or often grouped motor unit discharges at low discharge frequency during tetany episodes.
Tetanus toxin, also known as tetanospasmin is a potent neurotoxin produced by Clostridium tetani and causes the disease state, tetanus. The LD 50 of this toxin has been measured to be approximately 1 ng/kg, making it second only to botulinum toxin D as the deadliest toxin in the world. It functions very similarly to botulinum neurotoxin by ...
American lobster, Homarus americanus, has three fiber types including fast twitch fibers, slow-twitch and slow-tonic fibers. [50] Slow-tonic is a slow twitch-fiber that can sustain longer contractions . [51] [52] In lobsters, muscles in different body parts vary in the muscle fiber type proportions based on the purpose of the muscle group. [50]
“The proportion of slow-twitch to fast-twitch muscle fibers in a particular muscle varies depending on the function of the muscle and the type of training in which an individual participates.
Local tetanus is an uncommon form of the disease, in which people have persistent contraction of muscles in the same anatomic area as the injury. The contractions may persist for many weeks before gradually subsiding. Local tetanus is generally milder; only about 1% of cases are fatal, but it may precede the onset of generalized tetanus. [1]