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 a gene, and what is the relationship between genes, genotype, and phenotype?

• A. A gene is a sequence of amino acids; genes make up proteins; genotype determines phenotype
• B. A gene is a portion of DNA; genes determine traits; genotype is the genetic makeup; phenotype is the physical manifestation
• C. A gene is a protein; proteins determine traits; genotype is the set of all genes
• D. A gene is a lipid; lipids determine traits; phenotype is the physical manifestation

Correct answer: B

Rationale: A gene is a portion of DNA that contains the instructions for a specific trait. Genotype refers to the genetic makeup of an organism, encompassing all its genes. Phenotype, on the other hand, is the observable physical manifestation resulting from the interaction between an organism's genotype and environmental factors. Choice A is incorrect because genes do not consist of amino acids directly; they are sequences of nucleotides. Choice C is incorrect as genes do not determine traits directly but provide the instructions for proteins that may influence traits. Choice D is incorrect as genes are not lipids, and lipids do not determine traits; they are a type of biomolecule with different functions.

3. Which skin condition is characterized by patches of inflamed, reddened skin and is often triggered by allergens or stress?

• A. Eczema
• B. Psoriasis
• C. Acne
• D. Vitiligo

Correct answer: A

Rationale: Eczema is the correct answer. It presents as patches of inflamed, reddened skin and can be triggered by allergens, stress, or other factors. Psoriasis, on the other hand, is characterized by red, scaly patches rather than inflamed and reddened skin. Acne manifests as pimples and blemishes, not patches of inflamed skin. Vitiligo is characterized by the loss of skin color in patches, which is distinct from the symptoms described in the question.

4. Which hormone is released by the adrenal glands in response to stress?

• A. Insulin
• B. Cortisol
• C. Adrenaline
• D. Glucagon

Correct answer: C

Rationale: Adrenaline is the correct answer. It is released by the adrenal glands in response to stress to prepare the body for the 'fight or flight' response. Adrenaline increases heart rate, dilates airways, and mobilizes energy stores to help the body deal with the perceived threat. Insulin (Choice A) is produced by the pancreas to regulate blood sugar levels, not in response to stress. Cortisol (Choice B) is another hormone released by the adrenal glands in response to stress, but it primarily helps regulate metabolism and immune response. Glucagon (Choice D) is also produced by the pancreas to increase blood sugar levels when they are low, not by the adrenal glands in response to stress.

5. Which part of the brainstem controls heart rate and breathing?

• A. Medulla oblongata
• B. Pons
• C. Midbrain
• D. Thalamus

Correct answer: A

Rationale: The medulla oblongata is a critical part of the brainstem responsible for regulating essential functions such as heart rate, breathing, and blood pressure. It houses centers that oversee these involuntary processes, making it the correct answer. The pons, midbrain, and thalamus do not primarily control heart rate and breathing, thus making them incorrect choices for this question.

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