Nerve and muscle: muscle contraction, types of muscle fibers
Physiology · MBBS
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Study notes
After death, the body stiffens for hours then loosens — why? In life, ATP detaches myosin heads from actin after each power stroke, letting muscles relax. After death, ATP production stops; myosin locks onto actin permanently — rigor mortis, peaking ~12 hours. Later, enzymes digest the muscle proteins and the body softens again. Forensic doctors use this timeline to estimate time of death.
Related topics
- General physiology: cell, membrane transport, homeostasis
- Blood: RBC, hemoglobin, anemia basics, WBC, immunity basics
- Blood: platelets, hemostasis, coagulation, blood groups, transfusion
- Nerve and muscle: action potential, synapse, neuromuscular junction
- Cardiovascular system: cardiac cycle, heart sounds, ECG
- Cardiovascular system: hemodynamics, blood pressure regulation