MEDICAL PHYSIOLOGY

Detailed explanation-1: -A fused tetanic contraction is the strongest single-unit twitch in contraction. When tetanized, the contracting tension in the muscle remains constant in a steady state. This is the maximal possible contraction. During tetanic contractions, muscles can shorten, lengthen or remain constant length.

Detailed explanation-2: -In MH an acute increase of Ca2+ results in excessive muscle contraction causing rigidity, while in CCD a chronic rise of cytosolic Ca2+ is seen, leading to mitochondrial damage, disorganization of myofibrils and muscle weakness.

Detailed explanation-3: -Cardiac Muscle Similarly to skeletal muscles, the contraction of cardiac muscles is regulated by the concentration of calcium ions. However, some main differences in contraction mechanisms are that: The T-tubular system in cardiac muscles has much greater invaginations on the cell surface.

Detailed explanation-4: -Calcium released by L-type calcium channels or IP3Rs downstream from Gq-coupled cell-surface receptors causes smooth muscle contraction. It binds to calmodulin (CaM) and the resulting complex stimulates myosin light-chain (MLC) kinase (MLCK). This phosphorylates MLC to promote contraction.

Detailed explanation-5: -Tetanus is an infection caused by bacteria called Clostridium tetani. When these bacteria enter the body, they produce a toxin that causes painful muscle contractions. Another name for tetanus is “lockjaw”. It often causes a person’s neck and jaw muscles to lock, making it hard to open the mouth or swallow.