Osteoporosis,an age-related disease of the skeletal system,may occur due to:

Match List-$I$ with List-$II$ related to the muscular/skeletal system:

List-$I$	List-$II$
$A$. Tetany	$I$. Inflammation of joints
$B$. Arthritis	$II$. Autoimmune disorder affecting neuromuscular junction
$C$. Myasthenia gravis	$III$. Wild contraction in muscle due to low $Ca^{++}$ in body fluid
$D$. Muscular dystrophy	$IV$. Progressive degeneration of skeletal muscle

Choose the correct answer from the options given below:

Write a few lines about Gout.

Arthritis is the disease of

Which of the following is an incorrect statement about myasthenia gravis?
$(I)$ It is not an autoimmune disorder.
$(II)$ It affects the neuromuscular junction.
$(III)$ It occurs due to low $Ca^{++}$ in body fluid.
$(IV)$ Paralysis of skeletal muscle is a symptom of myasthenia gravis.

In Myasthenia gravis . . . . . . is affected.