Question Bank — Chemical Coordination and Integration

Section A — MCQs (10 questions, 1 mark each)

1. Which of the following is a peptide hormone that increases blood calcium levels?
   (a) Thyrocalcitonin (b) Parathyroid hormone (c) Insulin (d) Glucagon

2. The posterior pituitary stores and releases which of the following hormones synthesised in the hypothalamus?
   (a) Growth hormone and prolactin (b) Oxytocin and vasopressin (c) TSH and ACTH (d) FSH and LH

3. Assertion (A): Iodine is essential for the normal rate of synthesis of thyroid hormones.
   Reason (R): Deficiency of iodine in the diet results in hypothyroidism and enlargement of the thyroid gland called goitre.
   (a) Both A and R are true and R is the correct explanation of A.
   (b) Both A and R are true but R is not the correct explanation of A.
   (c) A is true but R is false.
   (d) A is false but R is true.

4. Which gland secretes melatonin that regulates the 24-hour diurnal rhythm of the body?
   (a) Pituitary (b) Pineal (c) Thyroid (d) Adrenal

5. Assertion (A): Glucagon is a hyperglycemic hormone.
   Reason (R): Glucagon stimulates glycogenolysis and gluconeogenesis in liver cells, resulting in increased blood sugar levels.
   (a) Both A and R are true and R is the correct explanation of A.
   (b) Both A and R are true but R is not the correct explanation of A.
   (c) A is true but R is false.
   (d) A is false but R is true.

6. The hormone secreted by the atrial wall of the heart that decreases blood pressure is:
   (a) Erythropoietin (b) Atrial natriuretic factor (c) Gastrin (d) Secretin

7. Which of the following is the main glucocorticoid secreted by the adrenal cortex?
   (a) Aldosterone (b) Cortisol (c) Epinephrine (d) Thymosin

8. The α-cells of the Islets of Langerhans secrete:
   (a) Insulin (b) Glucagon (c) Somatostatin (d) Pancreatic polypeptide

9. Which hormone stimulates the contraction of smooth muscles of the uterus during childbirth?
   (a) Vasopressin (b) Oxytocin (c) Prolactin (d) Progesterone

10. The thymus gland plays a major role in:
    (a) Calcium homeostasis (b) Differentiation of T-lymphocytes (c) Regulation of basal metabolic rate (d) Spermatogenesis

Section B — Very Short Answer (6 questions, 2 marks each)

1. Differentiate between exocrine and endocrine glands with one example of each.
2. Name the hormones secreted by the pars distalis of the pituitary gland.
3. What is the role of thyrocalcitonin (TCT) in calcium homeostasis?
4. State two functions of thymosins.
5. Name the hormones secreted by the adrenal medulla and mention their common name.
6. What is the function of atrial natriuretic factor (ANF)?

Section C — Short Answer (5 questions, 3 marks each)

1. Describe the role of insulin and glucagon in maintaining blood glucose homeostasis.
2. Explain the functions of estrogen and progesterone secreted by the ovary.
3. Write the functions of the hormones secreted by the gastrointestinal tract.
4. How do hormones interact with membrane-bound receptors? Explain with an example.
5. Describe the effects of over-secretion and under-secretion of growth hormone (GH) in humans.

Section D — Long Answer (3 questions, 5 marks each)

1. Describe the location and hormones secreted by the thyroid gland. Explain the effects of hypothyroidism and hyperthyroidism with examples. (Include a labelled diagram of the position of the thyroid and parathyroid glands.)
2. Explain the structure of the pituitary gland and the hormones secreted by its different parts along with their functions.
3. Describe the mechanism of hormone action with reference to hormones interacting with intracellular receptors. How do steroid hormones regulate gene expression?

Section E — Case/Source-Based (2 questions, 4 marks each)

Case 1:

A 45-year-old woman reports fatigue, weight gain, irregular menstrual cycles and swelling in the neck region. Medical tests reveal low levels of T3 and T4 with elevated TSH.

(a) Identify the probable disorder.
(b) Name the gland affected and the hormone whose deficiency causes this condition.
(c) What is the role of iodine in this context?
(d) Mention one consequence if this condition occurs during pregnancy.

Case 2:

A patient shows symptoms of excessive thirst, frequent urination and presence of glucose in urine. The condition is diagnosed as diabetes mellitus due to insufficient insulin action.

(a) Name the gland and cells responsible for insulin secretion.
(b) Explain how insulin maintains glucose homeostasis.
(c) What are ketone bodies and how are they related to this disorder?
(d) Name the other hormone secreted by the same cells of the pancreas and state its effect on blood glucose.