Nursing Elites

1. Which of the following sets of valves is primarily responsible for preventing blood flow from major blood vessels to the heart?

• A. atrioventricular valves
• B. semilunar valves
• C. tricuspid valves
• D. bicuspid valves

Correct answer: B

Rationale: The correct answer is B: semilunar valves. Semilunar valves are primarily responsible for preventing blood flow from major blood vessels to the heart. These valves are located at the base of the aorta and the pulmonary artery, ensuring blood flows in one direction only by closing when the ventricles relax to prevent blood from flowing back into the heart. Choices A, C, and D are incorrect. Atrioventricular valves (choice A) include the tricuspid and bicuspid valves, which prevent backflow between the atria and ventricles, not major blood vessels. Tricuspid valves (choice C) and bicuspid valves (choice D) are specific types of atrioventricular valves located between the atria and ventricles, not at the base of major blood vessels.

2. What is surgically altered during a vasectomy?

• A. Vas deferens
• B. Glans penis
• C. Prostate
• D. Urethra

Correct answer: A

Rationale: During a vasectomy, the vas deferens is surgically altered or cut to prevent the transport of sperm from the testicles to the urethra. This procedure is a form of permanent male sterilization. The glans penis, prostate, and urethra are not surgically altered during a vasectomy. Therefore, the correct answer is the vas deferens (Choice A), as it is the structure specifically targeted and modified in this procedure. The glans penis (Choice B) is the sensitive tip of the penis, the prostate (Choice C) is a gland vital for semen production but not involved in a vasectomy, and the urethra (Choice D) is the tube that carries urine and semen but is not surgically altered in a vasectomy.

3. Which type of muscle tissue contracts involuntarily and is found in organs like the heart and intestines?

• A. Skeletal muscle
• B. Cardiac muscle
• C. Smooth muscle
• D. All of the above

Correct answer: C

Rationale: Smooth muscle is the type of muscle tissue that contracts involuntarily and is found in organs like the heart and intestines. Skeletal muscle is responsible for voluntary movements, like those involved in skeletal system actions. Cardiac muscle is found in the heart and contracts involuntarily, but it is distinct from smooth muscle. The heart's muscle is specialized and forms the myocardium, which is not the same as the smooth muscle found in organs like the intestines. Therefore, the correct answer is C) Smooth muscle.

4. Which macromolecule will always contain nitrogen?

• A. Fatty acid
• B. Protein
• C. Lipid
• D. Carbohydrate

Correct answer: B

Rationale: The correct answer is B: Protein. Proteins always contain nitrogen, as it is a key element in amino acids, the building blocks of proteins. Fatty acids (choice A), lipids (choice C), and carbohydrates (choice D) do not always contain nitrogen. Fatty acids consist of long chains of hydrocarbons, lipids are mainly composed of carbon, hydrogen, and oxygen, and carbohydrates are composed of carbon, hydrogen, and oxygen as well, but not nitrogen.

5. What step of the scientific method must come before generating a hypothesis?

• A. Collecting and organizing data.
• B. Communicating the results in a scientific journal.
• C. Conducting an experiment.
• D. Researching previous studies for background.

Correct answer: D

Rationale: The correct answer is D, 'Researching previous studies for background.' Before formulating a hypothesis, it is essential to review existing literature, studies, and information related to the topic to understand the context and identify gaps in knowledge. This step helps researchers build on existing knowledge and formulate a clear hypothesis based on the information gathered. Choices A, B, and C are incorrect because they come after the step of researching previous studies and developing a hypothesis. Collecting and organizing data, conducting an experiment, and communicating results typically follow the hypothesis generation step in the scientific method.

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