Which of the following types of cells is primarily responsible for the destruction of old cells and invasive micro-organisms?

Correct Answer: D

Rationale: Macrophages are a type of white blood cell that plays a crucial role in the immune system by engulfing and digesting cellular debris, foreign substances, microbes, cancer cells, and old or damaged cells. Basophils are primarily involved in allergic reactions and parasitic infections, eosinophils combat multicellular parasites and have a role in allergic reactions, and B-cells are responsible for producing antibodies. Therefore, the correct answer is macrophages as they are specialized in phagocytosis and removal of unwanted cells and microorganisms.

Correct Answer: B

Rationale: The correct answer is stomach acid. Stomach acid, also known as gastric acid, plays a crucial role in destroying ingested pathogens due to its high acidity. The low pH of stomach acid helps to kill bacteria and other pathogens that may be present in the food we consume. Lymphatic fluid is involved in immune function and fat absorption, not pathogen destruction. Bicarbonate is a base that neutralizes stomach acid to prevent damage to the stomach lining. Lipase is an enzyme that aids in the digestion of fats but is not involved in pathogen destruction.

Correct Answer: C

Rationale: Ovulation is the release of a mature egg (ovum) from the Graafian follicle in the ovary. This process is essential for fertilization. Choice A is incorrect because the fallopian tube does not move the ovum to the uterus; rather, it provides a pathway for the egg to travel from the ovary to the uterus. Choice B is incorrect as the oocyte undergoes its first meiotic division after ovulation. Choice D is incorrect because the corpus luteum forms after ovulation and is responsible for producing progesterone.

Correct Answer: B

Rationale: Aldosterone is a hormone produced by the adrenal gland that plays a crucial role in regulating electrolyte levels in the body. The correct answer is B) Sodium levels are increased. Aldosterone acts on the kidneys to increase the reabsorption of sodium ions from the urine back into the bloodstream. This reabsorption of sodium leads to an increase in blood volume and blood pressure. Option A) Calcium levels are decreased is incorrect because aldosterone does not directly affect calcium levels. Option C) Potassium levels are increased is incorrect because aldosterone actually leads to the excretion of potassium ions in the urine, not an increase in potassium levels. Option D) Magnesium levels are decreased is incorrect as aldosterone's main role is to regulate sodium and potassium levels, not magnesium levels. In an educational context, understanding the role of aldosterone in electrolyte balance is crucial for healthcare professionals as imbalances can lead to various health issues like hypertension, electrolyte disturbances, and kidney disorders. A solid grasp of this concept is essential for providing safe and effective patient care.

Correct Answer: B

Rationale: Stimulation of the sympathetic nervous system leads to an increase in cardiac output. When the sympathetic nervous system is activated, it causes the heart to beat faster and with more force, leading to an increased cardiac output. Choices A, C, and D are incorrect because the sympathetic nervous system does not cause decreased blood flow to the skeletal muscles, decreased respiratory rate, or increased urinary output.