All of the following are organs of the digestive system except

Correct Answer: D

Rationale: The correct answer is D: the heart. The heart is not an organ of the digestive system. The digestive system is responsible for breaking down food and absorbing nutrients. The stomach, mouth, and intestines are all essential organs involved in this process. The heart, on the other hand, is part of the circulatory system, responsible for pumping blood throughout the body. It plays no direct role in digestion. Therefore, D is the correct answer.

Correct Answer: B

Rationale: The correct answer is B: fresh fruits and vegetables. Roughage, also known as dietary fiber, is essential for digestive health. Fruits and vegetables are rich in fiber, promoting healthy digestion, preventing constipation, and reducing the risk of chronic diseases. Red meat and poultry (choice A) are good sources of protein but lack fiber. Eggs and milk products (choice C) are also protein-rich but low in fiber. Animal fat and plant oil (choice D) are high in fats but do not provide fiber. Therefore, fresh fruits and vegetables are the best choice for including roughage in a balanced diet.

Correct Answer: B

Rationale: The correct answer is B: an ulcer. In the cartoon, the 'festering' pit indicates a hole or erosion in the stomach lining, which is characteristic of an ulcer. Ulcers are sores that form in the stomach or small intestine due to factors like bacterial infection or excessive acid production. Gallstones (A) are solid particles that form in the gallbladder, not in the stomach. Appendicitis (C) is inflammation of the appendix, not related to stomach issues. A goiter (D) is an enlargement of the thyroid gland, not linked to stomach ulcers. The 'festering' pit aligns with the symptoms and location of an ulcer, making it the most likely disorder represented.

Correct Answer: C

Rationale: The correct answer is C: Decreased urine production allows the body to conserve water. When an athlete sweats a lot during a long-distance run on a hot day, the body loses water through sweat. To prevent dehydration, the kidneys reduce urine production, allowing the body to retain more water. This helps maintain proper hydration levels and prevent water loss. Rationale: A: Decreased urine production does not directly impact amino acids in the blood. Amino acids are primarily regulated by protein metabolism and dietary intake. B: Increased urine production does not specifically target the removal of amino acids produced during exercise. Amino acids are typically metabolized and used for energy or protein synthesis. D: Increased urine production does not help more water remain in the bloodstream. Excess water is typically excreted to maintain fluid balance.

Correct Answer: C

Rationale: The correct answer is C: kidney. The nephron is the structural unit of the kidney responsible for filtering and processing blood to produce urine. The kidney's primary function is to regulate water and electrolyte balance in the body. Choices A, B, and D are incorrect because the nephron is not found in the lung, liver, or intestine. Each of these organs has its own specialized structures and functions unrelated to the nephron's role in kidney function.