Nursing Elites

1. The Gram stain is a differential staining technique used to classify bacteria based on their cell wall composition. Gram-positive bacteria appear

• A. Pink
• B. Blue
• C. Red
• D. Purple

Correct answer: D

Rationale: The Gram stain is a differential staining technique that categorizes bacteria into two groups based on their cell wall composition: Gram-positive and Gram-negative. Gram-positive bacteria have a thick layer of peptidoglycan in their cell walls, which retains the crystal violet stain used in the Gram staining procedure. Consequently, Gram-positive bacteria appear purple under the microscope after staining. On the other hand, Gram-negative bacteria possess a thinner peptidoglycan layer and an outer membrane that can be penetrated by the counterstain safranin, leading them to appear pink or red. Blue is not typically used to describe the color of bacteria in a Gram stain, making it an incorrect choice.

2. What is the most common cause of aseptic meningitis?

• A. Bacteria
• B. Viruses
• C. Fungi
• D. Parasites

Correct answer: B

Rationale: Aseptic meningitis is typically caused by viral infections, such as enteroviruses (e.g., coxsackievirus, echovirus), herpes simplex virus, varicella-zoster virus, and others. These viruses can infect the meninges, leading to inflammation and symptoms of meningitis without the presence of bacteria. While bacterial meningitis is a serious and life-threatening condition, aseptic meningitis caused by viruses is usually less severe and has a better prognosis. Fungi and parasites are less common causes of meningitis compared to bacteria and viruses.

3. Which statement about white blood cells is true?

• A. B cells are responsible for antibody production.
• B. White blood cells are produced in the bone marrow before entering the bloodstream.
• C. Platelets, a specialized class of blood cells, function to clot blood and stop bleeding.
• D. The majority of white blood cells are active throughout life, providing immunity across all age groups.

Correct answer: A

Rationale: The correct answer is A: B cells, a type of white blood cell, are responsible for producing antibodies in response to pathogens. Antibodies play a crucial role in identifying and neutralizing foreign substances like bacteria and viruses in the body, aiding in the immune response and protecting against infections. This function is essential for maintaining a healthy immune system. White blood cells, including B cells, are produced in the bone marrow before entering the bloodstream. Platelets, not white blood cells, are a specialized class of blood cells that function to clot blood and stop bleeding. While white blood cells provide immunity, not all of them are active throughout life as some have specific lifespans and functions.

4. During swallowing, what is the role of the epiglottis, a small flap of cartilage located near the base of the tongue?

• A. Initiates the swallowing reflex
• B. Grinds food into smaller pieces
• C. Covers the trachea to prevent food aspiration
• D. Stores saliva for lubrication

Correct answer: C

Rationale: The epiglottis plays a crucial role during swallowing by covering the trachea to prevent food or liquid from entering the airway, which could lead to aspiration. By acting as a lid over the trachea, it ensures that food passes down the esophagus to the stomach, preventing it from entering the lungs. Choice A is incorrect as the swallowing reflex is a coordinated muscular action involving the tongue and throat muscles. Choice B is incorrect as grinding food into smaller pieces is primarily the function of the teeth and the initial stages of digestion. Choice D is incorrect as the storage of saliva for lubrication is not a function of the epiglottis, but rather involves salivary glands.

5. Which type of epithelium lines the inner surface of the oral cavity, providing a barrier against external insults?

• A. Simple squamous epithelium
• B. Stratified squamous epithelium
• C. Simple columnar epithelium
• D. Pseudostratified columnar epithelium

Correct answer: B

Rationale: The oral cavity is constantly exposed to mechanical stress and potential injury from food particles and other external factors. To protect against these insults, a strong and resilient epithelium is needed. Stratified squamous epithelium is the best choice for lining the oral cavity due to its multiple layers of cells. This type of epithelium provides a robust barrier that can withstand abrasion and protect the underlying tissues. Simple squamous epithelium (choice A) is too thin and not suitable for a protective function. Simple columnar epithelium (choice C) is more suited for absorption and secretion functions, not protection against mechanical stress. Pseudostratified columnar epithelium (choice D) is found in respiratory passages and functions in mucociliary clearance, not in providing a protective barrier against external insults in the oral cavity.

Similar Questions