Which hormone increases $Ca^{++}$ levels?

Which of the following given organs are influenced by the activity of $PTH$?
The option containing all correct answers is
$I$. Kidney $II$. Bone $III$. Muscle $IV$. Intestine $V$. Brain

Parathormone induces

Tetany $(Irregular \text{ muscle contraction})$ and osteoporosis are caused due to the deficiency of

The pituitary gland,by virtue of its tropic hormones,controls the secretory activity of other endocrine glands. Which one of the following endocrine glands can function independently of the pituitary gland?

Calcium ion concentration in blood affects muscle contraction. Does it lead to tetany in certain cases? How will you correlate fluctuation in blood calcium with tetany?