Nursing Elites

1. Autoimmune diseases occur when the immune system mistakenly attacks healthy body tissues. What is a potential cause of autoimmune diseases?

• A. Deficiency in essential vitamins and minerals
• B. Exposure to environmental toxins
• C. Breakdown in immune cell self-tolerance mechanisms
• D. All of the above

Correct answer: C

Rationale: The correct answer is C. Autoimmune diseases are triggered by a breakdown in immune cell self-tolerance mechanisms, where the immune system fails to recognize 'self' from 'non-self' cells, leading to attacks on healthy tissues. While deficiencies in essential vitamins and minerals or exposure to environmental toxins can impact immune function, the root cause of autoimmune diseases is primarily attributed to the breakdown in self-tolerance mechanisms. This breakdown can be influenced by genetic predisposition, environmental factors, and other triggers, leading to the development of autoimmune conditions.

2. 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: C

Rationale: The correct answer is C: 'Producing mucus.' Cilia lining the respiratory tract do not produce mucus, but rather move the mucus that is produced by other cells. The cilia work together to propel the mucus upwards towards the throat, where it can be either swallowed or expelled. Trapping inhaled dust and debris, moistening inhaled air, and propelling mucus upwards are all important functions of the cilia in the respiratory tract, helping to protect the lungs and maintain respiratory health.

3. A closed system in ecology is one that:

• A. Exchanges energy but not matter
• B. Exchanges both energy and matter
• C. Exchanges neither energy nor matter
• D. Recycles nutrients efficiently

Correct answer: A

Rationale: Rationale: In ecology, a closed system is one that does not exchange matter with its surroundings but can exchange energy. This means that while energy can enter or leave the system, the amount of matter within the system remains constant. This definition aligns with option A, making it the correct answer. Options B and C are incorrect because a closed system does not exchange matter, and option D is not directly related to the definition of a closed system in ecology.

4. A pressure vessel has a cylindrical body (diameter 10cm, height 20cm) with hemispherical ends (same diameter as the cylinder). What is its total surface area?

• A. 785 sq cm
• B. 1130 sq cm
• C. 1570 sq cm
• D. 2055 sq cm

Correct answer: D

Rationale: Calculate the surface area of the cylinder (base + lateral surface) and two hemispheres. Add them all up for the total surface area.

5. What is the primary function of the coronary arteries in the cardiovascular system?

• A. Carry oxygenated blood to the heart muscle
• B. Carry deoxygenated blood from the heart muscle
• C. Pump blood to the lungs for oxygenation
• D. Regulate blood pressure in the systemic circulation

Correct answer: A

Rationale: The primary function of the coronary arteries in the cardiovascular system is to carry oxygenated blood to the heart muscle. These arteries supply the heart muscle with the necessary oxygen and nutrients it needs to function properly. Without adequate blood flow through the coronary arteries, the heart muscle can become deprived of oxygen, leading to conditions like angina or even a heart attack. Options B, C, and D are incorrect as they do not accurately describe the function of the coronary arteries. Option B is incorrect because the coronary arteries carry oxygenated blood, not deoxygenated blood. Option C is incorrect because the pulmonary arteries, not the coronary arteries, carry blood to the lungs for oxygenation. Option D is incorrect because the regulation of blood pressure in the systemic circulation is primarily controlled by mechanisms such as the kidneys and the autonomic nervous system, not the coronary arteries.

6. The tonsils and adenoids, located in the throat, are part of the:

• A. Lymphatic system
• B. Endocrine system
• C. Respiratory system
• D. Digestive system

Correct answer: A

Rationale: The correct answer is A: "Lymphatic system." The tonsils and adenoids are part of the lymphatic system, which plays a crucial role in the body's immune response. These tissues help trap and fight off bacteria and viruses that enter the body through the mouth and nose. The lymphatic system is responsible for producing white blood cells and antibodies that help protect the body from infections. Therefore, the tonsils and adenoids are essential components of the lymphatic system, not the endocrine, respiratory, or digestive systems.

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