The largest endocrine gland(s) that makes 3 hormones that affect the metabolism is the:

Correct Answer: C

Rationale: The correct answer is C: thyroid gland. The thyroid gland is the largest endocrine gland that produces 3 hormones (T3, T4, and calcitonin) that regulate metabolism. T3 and T4 control the body's metabolic rate, while calcitonin helps regulate calcium levels in the blood. The pancreas (A) primarily produces insulin and glucagon to regulate blood sugar levels. The adrenal glands (B) produce hormones like cortisol and adrenaline to regulate stress response. The pituitary gland (D) controls various other endocrine glands but does not primarily produce hormones affecting metabolism.

Correct Answer: B

Rationale: The correct answer is B: Pineal gland. The pineal gland secretes melatonin, a hormone that regulates the body's circadian rhythm. Melatonin helps control the sleep-wake cycle, making the pineal gland crucial for maintaining our internal body clock. The other choices, Thymus, Parathyroid, and Pituitary glands, are not directly involved in regulating circadian rhythms. Thymus is responsible for immune function, Parathyroid regulates calcium levels, and Pituitary gland controls various hormones but not specifically circadian rhythm. Hence, the pineal gland is the correct choice for this question.

Correct Answer: A

Rationale: The correct answer is A: Cretinism. Cretinism is a condition of severe hypothyroidism during childhood, leading to stunted growth, intellectual disability, and physical deformities. Myxoedema refers to severe hypothyroidism in adults, not children. Graves disease is a form of hyperthyroidism, opposite of hypothyroidism. Acromegaly is a condition caused by excess growth hormone, not related to thyroid dysfunction. Therefore, Cretinism is the correct answer for hypothyroidism in children due to its specific characteristics and presentation.

Correct Answer: A

Rationale: The correct answer is A: Parathyroid and thyroid. The parathyroid glands produce parathyroid hormone (PTH), which regulates calcium levels in the blood by increasing calcium absorption from the intestines and releasing calcium from bones. The thyroid gland produces calcitonin, which helps lower blood calcium levels by promoting calcium deposition in bones. The other choices (B: Adrenal medulla and pancreas, C: Testes, D: Parathyroid and thymus) are incorrect because they do not play a direct role in regulating calcium levels in the blood.

Correct Answer: A

Rationale: The correct answer is A: nervous system. The nervous system works closely with the endocrine system to coordinate the body's functions through the release of neurotransmitters and hormones. The nervous system uses electrical signals to transmit information rapidly, while the endocrine system releases hormones into the bloodstream to regulate various bodily functions. The immune system (B) protects the body from infections, the circulatory system (C) transports nutrients and oxygen throughout the body, and the respiratory system (D) is responsible for gas exchange. However, these systems do not directly coordinate with the endocrine system in the same way the nervous system does.