Nokea
Thyroid hormones (T3 and T4):
- A. increase metabolic rate.
- B. are hydrophilic as they are made from amino acids.
- C. contain iron atoms in ferrous form.
- D. stimulate the secretion of thyroid-stimulating hormone (TSH; thyrotropin).
Correct Answer: A
Rationale: Thyroid hormones, T3 (triiodothyronine) and T4 (thyroxine), play a crucial role in regulating metabolism in the body. They are responsible for increasing the metabolic rate of cells by influencing the production of proteins and controlling how the body uses energy. This increase in metabolic rate results in processes such as increased heart rate, enhanced nutrient breakdown, and higher body temperature. Thus, option A, "increase metabolic rate," is the correct statement regarding thyroid hormones (T3 and T4).
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Which age group does acromegaly most commonly affect?
- A. 30-50 years
- B. 10-25 years
- C. 55-70 years
- D. 25-40 years
Correct Answer: A
Rationale: Acromegaly most commonly affects individuals in the age group of 30-50 years. This condition is typically diagnosed in adults between these ages. Acromegaly is often caused by the overproduction of growth hormone in adults, which leads to excessive bone growth and tissue expansion. While acromegaly can develop at any age, it is more commonly seen in adults within the 30-50 age range.
Enlargement of the bones of the hands, feet, and face due to overproduction of growth hormone is called :
- A. Acromegaly
- B. Cushing syndrome
- C. Gigantism
- D. Myxedema
Correct Answer: A
Rationale: Acromegaly is the condition characterized by the enlargement of the bones of the hands, feet, and face due to the overproduction of growth hormone in adults. This excess growth hormone typically comes from a benign tumor in the pituitary gland, leading to the gradual enlargement of these body parts. Cushing syndrome, on the other hand, is caused by prolonged exposure to high levels of cortisol and is not directly related to bone enlargement. Gigantism is the condition of excessive growth in height due to overproduction of growth hormone occurring in children before the closure of growth plates. Myxedema is a term used to describe severe hypothyroidism and is not directly associated with bone enlargement.
Which of the following lung cancers is most commonly associated with the syndrome of inappropriate secretion of antidiuretic hormone (SIADH)?
- A. Squamous cell carcinoma
- B. Small cell (oat cell) carcinoma
- C. Large cell carcinoma
- D. Adenocarcinoma
Correct Answer: B
Rationale: Small cell (oat cell) carcinoma of the lung is most commonly associated with the syndrome of inappropriate secretion of antidiuretic hormone (SIADH). This paraneoplastic syndrome occurs in patients with small cell lung cancer due to the production of antidiuretic hormone (ADH) by the tumor cells. The excessive release of ADH leads to water retention and dilutional hyponatremia, causing symptoms such as nausea, confusion, seizures, and potentially life-threatening complications. Other types of lung cancer, such as squamous cell carcinoma, large cell carcinoma, and adenocarcinoma, are less commonly associated with SIADH.
All the following are effects of hypercalcemia except
- A. Diarrhea
- B. Polyuria
- C. A shortened qt interval
- D. Nephrolithiasis
Correct Answer: C
Rationale: Hypercalcemia refers to elevated levels of calcium in the blood. The effects of hypercalcemia include increased urinary frequency (polyuria), gastrointestinal symptoms such as constipation rather than diarrhea, kidney stones (nephrolithiasis), and various cardiac abnormalities. One key cardiac abnormality associated with hypercalcemia is a prolonged QT interval rather than a shortened QT interval. Prolongation of the QT interval can predispose individuals to arrhythmias, particularly Torsades de pointes. Therefore, the correct answer is C, as a shortened QT interval is not a typical effect of hypercalcemia.
Obesity is associated with an increased incidence of all the following except
- A. Diabetes mellitus
- B. Cancer
- C. Hypertension
- D. Chronic obstructive lung disease
Correct Answer: D
Rationale: Obesity is associated with an increased risk of developing various health conditions, including diabetes mellitus, cancer, and hypertension. However, chronic obstructive lung disease (COPD) is not directly linked to obesity. COPD is primarily caused by exposure to harmful particles or gases, most commonly from cigarette smoke. While obesity can impact lung function and worsen symptoms in individuals with COPD, it is not a direct cause of the condition. Therefore, the correct answer is D, chronic obstructive lung disease.