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. Signs of aging at the cellular level are

A. graying hair, waning strength, and wrinkles.
B. unrepaired DNA and abnormal proteins.
C. impaired cell division and the ability to break down and recycle worn cell parts.
D. a fatty liver and clogged blood vessels.

Correct answer: C

Rationale: The correct answer is 'impaired cell division and the ability to break down and recycle worn cell parts.' Aging at the cellular level involves reduced efficiency in cell division and the breakdown/recycling of cellular components, leading to functional decline. Choices A, B, and D are incorrect because they involve external physical manifestations or organ-specific issues rather than cellular-level changes associated with aging.

3. Magnetic resonance imaging might be used to

A. distinguish between normal and abnormal tissue.
B. examine an injured knee.
C. provide detailed images of the brain.
D. do both A and B.

Correct answer: B

Rationale: Magnetic resonance imaging, commonly known as MRI, is a non-invasive imaging technique used to visualize internal structures of the body. While it can be used to distinguish between normal and abnormal tissue, one of its common applications is to examine musculoskeletal injuries, such as an injured knee. Choice A has been corrected to mention 'normal and abnormal tissue' instead of 'normal and cancerous tissue' as MRI is not solely used for cancer detection. Choice C is incorrect as MRI can provide detailed images of various body parts, not just limited to the brain. Therefore, the correct answer is to examine an injured knee.

4. Testosterone production is regulated by which of the following glands?

A. Pineal
B. Thymus
C. Parathyroid
D. Pituitary

Correct answer: D

Rationale: Testosterone production is regulated by the pituitary gland. The pituitary gland secretes luteinizing hormone (LH), which stimulates the Leydig cells in the testes to produce testosterone. This hormone is not regulated by the Pineal, Thymus, or Parathyroid glands. The Pineal gland is responsible for secreting melatonin, the Thymus gland is involved in immune function, and the Parathyroid glands regulate calcium levels in the blood.

5. 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: D

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.