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: Macrophages

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 structures, located at the end of the ear canal, vibrates when sound waves strike it?

A. Acoustic meatus
B. Cochlea
C. Eustachian tube
D. Tympanic membrane

Correct answer: Tympanic membrane

Rationale: The correct answer is the Tympanic membrane. The tympanic membrane, also known as the eardrum, is located at the end of the ear canal and vibrates when sound waves strike it. This vibration is then transmitted to the ossicles in the middle ear, which amplify and transmit the sound to the inner ear. Choice A, the Acoustic meatus, is incorrect as it is the ear canal itself, not the structure that vibrates. Choice B, the Cochlea, is responsible for translating sound vibrations into electrical signals but is not located at the end of the ear canal. Choice C, the Eustachian tube, is responsible for equalizing pressure between the middle ear and the atmosphere and is not involved in vibration from sound waves.

3. What is the most useful application of ultrasonography for diagnostic examination?

A. dense organs, such as bones.
B. air-filled organs, such as lungs.
C. soft internal structures, such as fetuses.
D. microscopic structures.

Correct answer: soft internal structures, such as fetuses.

Rationale: Ultrasonography is a medical imaging technique that uses sound waves to visualize internal body structures. It is particularly effective for examining soft tissues like organs, blood vessels, and fetuses. Choice A is incorrect because bones are better visualized using techniques like X-rays. Choice B is incorrect as air-filled organs like lungs are not well visualized with ultrasound due to air being a poor conductor of sound waves. Choice D is incorrect since ultrasonography cannot visualize structures at a microscopic level, as it is used for larger internal structures.

4. 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: Sodium levels are increased

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.

5. Does the digestive system filter wastes from the blood?

A. True
B. False
C. Not Sure
D. None of the above

Correct answer: False

Rationale: The correct answer is False. The digestive system is responsible for breaking down food and absorbing nutrients, not filtering wastes from the blood. The excretory system, particularly the kidneys, filters wastes from the blood to form urine. Choices A, C, and D are incorrect because the digestive system's primary function is not waste filtration but rather digestion and absorption of nutrients.