Nursing Elites

1. Where do nearly all of the gaseous exchanges between air and blood take place in the lungs?

• A. Pleura
• B. Trachea
• C. Bronchioles
• D. Alveoli

Correct answer: D

Rationale: Nearly all gaseous exchanges between air and blood take place in the alveoli of the lungs. The walls of the alveoli are thin and surrounded by an extensive network of tiny blood vessels called capillaries. Oxygen from the air diffuses through the alveoli walls and into the bloodstream, while carbon dioxide, a waste product, diffuses from the blood into the alveoli to be exhaled out of the body. This process is essential for respiration and providing oxygen to the body's cells. Choices A, B, and C are incorrect. Pleura is the membrane surrounding the lungs, trachea is the windpipe that carries air to the lungs, and bronchioles are the smaller air passages in the lungs. However, the primary site for gaseous exchange is the alveoli due to their structure and function.

2. What is the primary function of the skin in the integumentary system?

• A. Regulating body temperature
• B. Protecting the body from external damage
• C. Producing red blood cells
• D. Producing hormones

Correct answer: B

Rationale: The primary function of the skin in the integumentary system is to protect the body from external damage. The skin acts as a barrier against pathogens, UV radiation, and physical trauma. While the skin does help regulate body temperature by sweating and vasodilation, its main role is protection. Skin does not produce red blood cells; this is the function of the bone marrow. Hormones are primarily produced by endocrine glands, not the skin.

3. Where does digestion begin in the digestive system?

• A. Stomach
• B. Mouth
• C. Small intestine
• D. Esophagus

Correct answer: B

Rationale: Digestion begins in the mouth. Mechanical digestion through chewing and chemical digestion through saliva initiate the breakdown of food. Enzymes in saliva start breaking down carbohydrates, marking the beginning of the digestive process. The stomach primarily functions in further breaking down food and mixing it with gastric juices. The small intestine is where most of the digestion and absorption of nutrients occur. The esophagus is a muscular tube that helps move food from the mouth to the stomach, but digestion does not begin there.

4. Which of the heart's four chambers is the largest and the strongest?

• A. Right atrium
• B. Left ventricle
• C. Right ventricle
• D. Left atrium

Correct answer: B

Rationale: The left ventricle is the largest and strongest chamber of the heart. It pumps oxygenated blood to the body, making it vital for systemic circulation. The right atrium receives deoxygenated blood from the body, the right ventricle pumps this blood to the lungs, and the left atrium receives oxygenated blood from the lungs.

5. What role does the liver play in metabolism?

• A. To produce bile
• B. To detoxify harmful substances
• C. To store glucose
• D. To produce insulin

Correct answer: B

Rationale: The correct answer is B: 'To detoxify harmful substances.' The liver is primarily responsible for detoxifying harmful substances present in the blood as part of its role in metabolism. While the liver does produce bile to aid in digestion and stores glucose for energy regulation, its main function in metabolism is detoxification. The liver does not produce insulin; insulin is produced by the pancreas to regulate blood sugar levels.

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