Question

Which of the following pairs of hormones are not antagonistic (having opposite effects) to each other?

• A. Parathormone- Calcitonin
• B. Insulin- Glucagon
• C. Relaxin- Inhibin
• D. Aldosterone- Atrial Natriuretic Factor

Answer 1

Answer: (C)

• Relaxin is a hormone produced by the ovary and the placenta with important effects on the female reproductive system and during pregnancy. In preparation for childbirth, it relaxes the ligaments in the pelvis and softens and widens the cervix.
• Inhibin is a protein secreted by granulosa (female) and Sertoli (male) cells in response to FSH, and its major action is the negative feedback control of pituitary FSH secretion.
• Parathyroid hormone regulates calcium levels in the blood, largely by increasing the levels when they are too low. It does this through its actions on the kidneys, bones, and intestine.
• Calcitonin is a hormone that is produced in humans by the parafollicular cells (commonly known as C-cells) of the thyroid gland. Calcitonin is involved in helping to regulate levels of calcium and phosphate in the blood, opposing the action of parathyroid hormone.
  
• Insulin is a hormone that plays a number of roles in the body's metabolism. Insulin regulates how the body uses and stores glucose and fat. Many of the body's cells rely on insulin to take glucose from the blood for energy.
• Glucagon is a hormone that is involved in controlling blood sugar (glucose) levels. It is secreted into the bloodstream by the alpha cells, found in the islets of Langerhans, in the pancreas.
• The aldosterone hormone is a hormone produced by the adrenal gland. The hormone acts mainly in the functional unit of the kidneys to aid in the conservation of sodium, secretion of potassium, water retention and to stabilize blood pressure.
• Atrial natriuretic factor (ANF) is a 28 amino acid polypeptide hormone secreted mainly by the heart atria in response to atrial stretch. ANF acts on the kidney to increase sodium excretion and GFR, to antagonize renal vasoconstriction, and to inhibit renin secretion.