Nursing Elites

1. The immune response can be categorized into two main branches:

• A. Humoral and cellular
• B. Innate and adaptive
• C. Primary and secondary
• D. Active and passive

Correct answer: A

Rationale: - The immune response can be broadly categorized into two main branches: the humoral immune response and the cellular immune response. - The humoral immune response involves the production of antibodies by B cells and is primarily responsible for defending against extracellular pathogens such as bacteria and viruses in the bloodstream and tissues. - The cellular immune response involves the activation of T cells, which can directly kill infected cells or help coordinate the immune response. This branch is crucial for combating intracellular pathogens like viruses and some bacteria. - Options B, C, and D do not accurately represent the main branches of the immune response and are therefore incorrect.

2. How does sunscreen protect the skin from harmful ultraviolet (UV) rays?

• A. By reflecting UV rays away from the skin
• B. By absorbing UV rays and converting them to heat
• C. By blocking UV rays completely
• D. By stimulating melanin production

Correct answer: B

Rationale: Sunscreen works by absorbing UV rays and converting them to heat. This mechanism helps to prevent the UV rays from penetrating the skin and causing damage such as sunburn, premature aging, and skin cancer. Reflecting UV rays away from the skin (option A) is not the primary function of sunscreen. While sunscreen does block UV rays, it does not do so completely (option C) as some UV rays may still penetrate the skin. Sunscreen does not stimulate melanin production (option D) as a means of protecting the skin from UV rays.

3. Which of the following epithelial tissues lines the stratified squamous epithelium of the esophagus, providing a protective barrier against abrasion from food passage?

• A. Simple squamous epithelium
• B. Stratified squamous epithelium
• C. Simple cuboidal epithelium
• D. Stratified cuboidal epithelium

Correct answer: B

Rationale: The correct answer is stratified squamous epithelium. This type of epithelium is found in areas subjected to mechanical and chemical stresses, such as the lining of the esophagus. The multiple layers of cells provide protection against abrasion from the passage of food. Simple squamous epithelium (choice A) is a single layer of flat cells and is not well-suited for protection against abrasion as it lacks the multiple layers. Simple cuboidal epithelium (choice C) is found in areas where secretion and absorption occur, such as kidney tubules, and is not typically found in the esophagus where protection against abrasion is necessary. Stratified cuboidal epithelium (choice D) is rare in the body and is not a characteristic tissue type of the esophagus, which requires stratified squamous epithelium for its protective function.

4. Which hormone plays a key role in stimulating the release of milk from breast tissue after childbirth?

• A. Follicle-stimulating hormone (FSH)
• B. Luteinizing hormone (LH)
• C. Prolactin
• D. Estrogen

Correct answer: C

Rationale: Prolactin is the hormone responsible for stimulating the release of milk from breast tissue after childbirth. It is produced by the pituitary gland and plays a crucial role in lactation. Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) are involved in the menstrual cycle and reproductive processes, not milk production. Estrogen is a female sex hormone with various functions but is not directly involved in milk production.

5. Which of the following structures plays a crucial role in controlling the cell cycle and preventing uncontrolled cell growth?

• A. The centrioles
• B. The nucleolus
• C. The Golgi apparatus
• D. The endoplasmic reticulum

Correct answer: A

Rationale: The correct answer is A: The centrioles. Centrioles are cylindrical structures found in animal cells that are crucial in organizing the spindle fibers during cell division (mitosis). They play a vital role in separating chromosomes during cell division, ensuring each daughter cell receives the correct number of chromosomes. Additionally, centrioles are involved in the formation of cilia and flagella, essential for cell motility and sensory functions. The nucleolus is responsible for ribosome production, the Golgi apparatus processes and packages proteins, and the endoplasmic reticulum is involved in protein synthesis and lipid metabolism. These structures do not have a direct role in controlling the cell cycle and preventing uncontrolled cell growth.

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