Circulatory System

Step 1: Understanding the Fetal Circulatory Adaptations
- Statement I is incorrect: The correct name of the fetal heart opening is foramen ovale, not foramen Manro.
- Statement II is correct: The ligamentum arteriosum is a remnant of the ductus arteriosus, connecting the pulmonary and systemic circulation.

- I is incorrect because diabetes insipidus is caused by a deficiency of antidiuretic hormone (ADH), not insulin.
- II is incorrect because Tetanus is not caused by thyroid hormone, but by a bacterial infection (Clostridium tetani).
- III is correct because cortisol is produced by the adrenal glands, and Cushing’s syndrome is caused by excess cortisol.
- IV is correct because somatotropin (growth hormone) is produced by the pituitary gland, and dwarfism is caused by a deficiency of growth hormone.

Step 1: The first statement is correct because angina pectoris is indeed a warning signal that suggests a temporary decrease in blood supply to the heart. This condition is usually caused by a blockage or narrowing of the coronary arteries.
Step 2: The second statement is also correct. Coronary artery disease, often referred to as atherosclerotic heart disease, involves the buildup of fatty deposits and plaque in the coronary arteries, which can lead to a reduction in blood flow to the heart. Step 3: Therefore, both statements I and II are true, and the correct answer is option (1).

- Statement I is incorrect because the superior colliculi are primarily involved in visual processing, not auditory functions.
- Statement II is also incorrect because the inferior colliculi are involved in auditory processing, not visual function.
- Statement III is correct; the pneumotaxic center, which regulates the rate and pattern of breathing, is located in the pons varoli.
- Statement IV is correct because the thermoregulatory center, responsible for regulating body temperature, is located in the hypothalamus.