Osteoporosis, an age-related disease of skeletal system, may occur due to
- immune disorder affecting neuromuscular junction leading to fatigue
- high concentration of Ca++ and Na+
- decreased level of estrogen
- accumulation of uric acid leading to inflammation of joints.
Answer
(3) decreased level of estrogen
Solution
As per NCERT, osteoporosis is an age-related disorder characterised by decreased bone mass and increased chances of fractures; decreased levels of estrogen is a common cause.
⇒ An autoimmune disorder affecting the neuromuscular junction is myasthenia gravis, and accumulation of uric acid crystals causing inflammation of joints is gout.
∴ Osteoporosis may occur due to decreased level of estrogen.
Answer: (3)