Lesson 11 of 12 · 5 min
Disorders of muscular and skeletal system
NCERT §17.5
Meher's grandmother takes calcium tablets because her bones have thinned. Her grand-uncle's big toe sometimes swells painfully. Both are disorders of this system.
The lesson in notes
In short
Myasthenia gravis: an autoimmune disorder of the neuromuscular junction, causing fatigue, weakening and paralysis of skeletal muscle.
Muscular dystrophy: skeletal muscle wastes away progressively, in most cases because of a genetic disorder.
Tetany: rapid spasms (wild contractions) of muscle caused by low Ca²⁺ in body fluid.
Arthritis: inflammation of joints.
Osteoporosis: an age-related disorder with reduced bone mass and higher chances of fractures; lower oestrogen is a common cause.
Gout: inflammation of joints due to build-up of uric acid crystals.