Endocrine System — Set 4
Biology · अंतःस्रावी तंत्र · Questions 31–40 of 60
Which hormone is responsible for maintaining the secondary sexual characteristics in females?
Correct Answer: A. Estrogen
Estrogen promotes the development of female reproductive organs and the menstrual cycle. It is primarily produced by the ovaries but small amounts come from the adrenal glands. It also plays a role in maintaining bone health in women.
Gigantism is a condition that results from the oversecretion of which hormone?
Correct Answer: A. Growth Hormone
Gigantism occurs when there is an excess of growth hormone during childhood before the bone plates fuse. This leads to abnormal height and overall excessive body growth. In adults, the same excess leads to a condition called acromegaly.
Which hormone stimulates the contraction of the gallbladder to release bile into the digestive tract?
Correct Answer: B. Cholecystokinin
Cholecystokinin is secreted by the small intestine in response to fats and proteins. It acts on the gallbladder to trigger the release of bile for fat emulsification. This is part of the complex hormonal coordination of human digestion.
Acromegaly, the enlargement of hands, feet, and face bones, occurs in adults due to excess?
Correct Answer: B. Growth Hormone
In adults, since bones can no longer grow in length, excess growth hormone causes bones to thicken. This results in the characteristic changes in facial features and limb size. It is usually caused by a benign tumor in the pituitary gland.
Which gland produces the hormone 'Calcitriol', the active form of Vitamin D?
Correct Answer: A. Kidneys
The kidneys convert vitamin D from precursors into calcitriol to help the body absorb calcium. This hormone is vital for maintaining healthy bone mineral density. Without it, bones become soft and weak, leading to rickets or osteomalacia.
Which hormone triggers the release of an egg from the ovary during ovulation?
Correct Answer: D. Luteinizing Hormone
Luteinizing Hormone (LH) surges in the middle of the menstrual cycle to trigger ovulation. It also stimulates the remains of the follicle to become the corpus luteum. In males, it stimulates the production of testosterone by the testes.
The adrenal medulla primarily secretes which pair of hormones?
Correct Answer: B. Adrenaline and Noradrenaline
The correct answer is 'Adrenaline and Noradrenaline'. These catecholamines are released during stressful or dangerous situations for rapid body response. They increase alertness, boost heart rate, and raise blood sugar for energy. Unlike the adrenal cortex, the medulla is directly controlled by the nervous system.
Which hormone is responsible for the darkening of the skin in many vertebrate species?
Correct Answer: C. Melanocyte Stimulating Hormone
Melanocyte Stimulating Hormone (MSH) acts on pigment cells to produce more melanin. While its role in humans is less pronounced than in some animals, it still influences skin pigmentation. It is produced by the intermediate lobe of the pituitary gland.
Which of the following is a symptom of 'Cretinism', caused by thyroid deficiency in infants?
Correct Answer: A. Stunted physical and mental growth
Cretinism leads to severe developmental delays if thyroid hormones are missing during early growth. It is often caused by maternal iodine deficiency or congenital thyroid problems. Early screening and treatment are essential to prevent permanent disability.
What is the primary function of the hormone 'Thymosin'?
Correct Answer: C. Maturation of immune T-cells
Thymosin is secreted by the thymus gland to help T-lymphocytes differentiate and become active. These cells are the warriors of the immune system that fight infections and cancer. The thymus is most active during childhood and early development.