which of the following types of cells is primarily responsible for the destruction of old cells and invasive micro organisms

ATI RN

ATI Anatomy and Physiology

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

A. Basophils
B. Eosinophils
C. B-cells
D. Macrophages

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.

2. Which of the following ions is most abundant in extracellular fluid?

A. Calcium
B. Chloride
C. Sodium
D. Potassium

Correct answer: C

Rationale: Sodium is the most abundant ion in extracellular fluid. It plays a crucial role in maintaining fluid balance, nerve function, and muscle contraction. Calcium (Choice A) is mainly found in bones and teeth, Chloride (Choice B) is the major anion in extracellular fluid but not the most abundant ion, and Potassium (Choice D) is found predominantly inside cells.

3. What effect does aldosterone secretion have on electrolyte levels?

A. Calcium levels are decreased
B. Sodium levels are increased
C. Potassium levels are increased
D. Magnesium levels are decreased

Correct answer: B

Rationale: Aldosterone is a hormone that primarily acts on the kidneys to increase the reabsorption of sodium and water into the bloodstream. As a result, sodium levels are increased. Choices A, C, and D are incorrect. Aldosterone does not significantly affect calcium, potassium, or magnesium levels.

4. What causes wrinkled and sagging skin?

A. Drinking too much water
B. Heredity alone
C. Loss of subcutaneous fat and reduced levels of elastin and collagen
D. Excess subcutaneous fat

Correct answer: C

Rationale: Wrinkled and sagging skin is primarily caused by the loss of subcutaneous fat and reduced levels of elastin and collagen in the skin. Choice A is incorrect as drinking too much water does not lead to wrinkled and sagging skin. Choice B is incorrect because heredity alone does not cause this condition. Excess subcutaneous fat, as mentioned in Choice D, can contribute to a different skin appearance, such as puffiness, but not wrinkled and sagging skin.

5. Which of the following organs is in the abdominopelvic cavity?

A. The heart
B. The trachea
C. The thymus
D. The liver

Correct answer: D

Rationale: The correct answer is the liver. The liver is located in the abdominopelvic cavity, which is the space between the diaphragm and the pelvic floor. The heart, trachea, and thymus are not located in the abdominopelvic cavity. The heart is situated in the thoracic cavity, the trachea is in the neck region, and the thymus is located in the upper chest. Understanding the anatomical locations of organs is crucial for medical professionals to accurately diagnose and treat patients.