Parathyroid disorders: It causes the lowering of blood calcium level. This increases the excitability of nerves and muscles causing cramps and convulsions.

Correct Option: D

Parathyroid disorders: It causes the lowering of blood calcium level. This increases the excitability of nerves and muscles causing cramps and convulsions.

A peptide hormone secreted by the parathyroid gland in response to low levels of calcium in the blood. It acts to maintain normal blood levels of calcium by increasing the number of osteoclasts, which break down the bone matrix and release calcium into the blood. It also increases the reabsorption of calcium and magnesium ions in the kidney tubules, so that their concentration is maintained in the blood.

Correct Option: A

A peptide hormone secreted by the parathyroid gland in response to low levels of calcium in the blood. It acts to maintain normal blood levels of calcium by increasing the number of osteoclasts, which break down the bone matrix and release calcium into the blood. It also increases the reabsorption of calcium and magnesium ions in the kidney tubules, so that their concentration is maintained in the blood.

Goitre is caused by deficiency of iodine in diet. Iodine is needed for the synthesis of thyroxine. Toxic agents present in food interfere with thyroxine synthesis and lead to goitre.

Correct Option: C

Goitre is caused by deficiency of iodine in diet. Iodine is needed for the synthesis of thyroxine. Toxic agents present in food interfere with thyroxine synthesis and lead to goitre.

Myxoedema is caused by deficiency of thyroid hormone or thyroxine in adults. It is characterised by increase in body weight, puffy appearance, low metabolic rate, and tendency to retain water in tissues.

Correct Option: B

Myxoedema is caused by deficiency of thyroid hormone or thyroxine in adults. It is characterised by increase in body weight, puffy appearance, low metabolic rate, and tendency to retain water in tissues.

Human chorionic gonadotropin is released by Anophoblast cells of the placenta. Estrogen and progesterone are also released by placental cells to maintain pregnancy. Prolactin is secreted from anterior lobe of pituitary. Placenta secretes Human Placental Lactogenic Factor which prepare mammary glands to secrete milk.

Correct Option: B

Human chorionic gonadotropin is released by Anophoblast cells of the placenta. Estrogen and progesterone are also released by placental cells to maintain pregnancy. Prolactin is secreted from anterior lobe of pituitary. Placenta secretes Human Placental Lactogenic Factor which prepare mammary glands to secrete milk.