Nursing Elites

1. Which level of protein structure is defined by the folds and coils of the protein's polypeptide backbone?

• A. Primary
• B. Secondary
• C. Tertiary
• D. Quaternary

Correct answer: B

Rationale: The correct answer is B: Secondary. The secondary structure of a protein is defined by the folds and coils of the protein's polypeptide backbone. This level of structure is characterized by the formation of alpha helices and beta sheets, which are stabilized by hydrogen bonds between amino acids along the polypeptide chain. Choice A, Primary, refers to the linear sequence of amino acids in the protein. Choice C, Tertiary, involves the 3D folding of the entire polypeptide chain. Choice D, Quaternary, pertains to the arrangement of multiple polypeptide subunits in a protein complex.

2. What controls the involuntary, rhythmic contractions of the heart muscle?

• A. Lungs
• B. Brain
• C. Spinal cord
• D. Sinoatrial node (located within the heart)

Correct answer: D

Rationale: The correct answer is D: Sinoatrial node (located within the heart). The involuntary, rhythmic contractions of the heart muscle are controlled by a specialized group of cells located within the heart called the sinoatrial node (SA node). The SA node acts as the heart's natural pacemaker, producing electrical impulses that regulate the heart rate and synchronize the contractions of the heart muscle. Choices A, B, and C (Lungs, Brain, Spinal cord) are not responsible for directly influencing the rhythmic contractions of the heart muscle.

3. What is the body's primary defense against pathogens?

• A. Phagocytes
• B. Antibodies
• C. Memory B cells
• D. T lymphocytes

Correct answer: A

Rationale: The correct answer is A: Phagocytes. Phagocytes are the body's first line of defense against pathogens. They are innate immune cells that engulf and digest foreign particles like bacteria and viruses, preventing infections. Phagocytes act as the initial barrier to invading pathogens and are part of the innate immune response. Choice B, Antibodies, are produced by B cells in the adaptive immune response. Choice C, Memory B cells, are also part of the adaptive immune response and provide a faster and stronger response upon re-exposure to pathogens. Choice D, T lymphocytes, are part of the adaptive immune response, particularly involved in cell-mediated immunity.

4. What is the main consequence of a malfunctioning thyroid gland that produces abnormally low levels of thyroid hormones?

• A. Increased energy levels and weight loss
• B. Decreased heart rate and body temperature
• C. Enhanced muscle growth and bone development
• D. Faster metabolism and heightened alertness

Correct answer: B

Rationale: The correct answer is B: Decreased heart rate and body temperature. A malfunctioning thyroid gland that produces abnormally low levels of thyroid hormones leads to hypothyroidism, resulting in decreased metabolic activity. This reduction in metabolic rate can cause a decreased heart rate and lower body temperature. Choices A, C, and D are incorrect because hypothyroidism typically manifests as symptoms such as fatigue, weight gain, cold intolerance, bradycardia, and decreased body temperature, rather than increased energy levels, enhanced muscle growth, faster metabolism, or heightened alertness.

5. Which of the following is NOT a function of the cilia lining the respiratory tract?

• A. Trapping inhaled dust and debris
• B. Moistening inhaled air
• C. Producing mucus
• D. Propelling mucus upwards towards the throat

Correct answer: B

Rationale: The correct answer is B: Moistening inhaled air. The cilia lining the respiratory tract primarily function to trap inhaled dust and debris, produce mucus, and propel the mucus upwards towards the throat for removal. Moistening inhaled air is primarily done by the mucous membranes in the nasal passages, which contain blood vessels that help warm and humidify the air as it passes through the nasal cavity. Therefore, the function of moistening inhaled air is not directly associated with the cilia in the respiratory tract, making it the correct choice in this scenario. Choices A, C, and D are incorrect as they are all functions carried out by the cilia in the respiratory tract.

Similar Questions