Any of the following may provoke an immune response except:

Correct Answer: D

Rationale: Correct Answer: D Rationale: 1. An injury to tissue can lead to inflammation, activating the immune response. 2. Influenza virus is a foreign pathogen that triggers the immune system to produce antibodies. 3. Cancer cells can be recognized as foreign and targeted by the immune system. 4. Choice D is correct because all options (A, B, and C) can provoke an immune response due to tissue damage, pathogens, or abnormal cells.

Correct Answer: B

Rationale: The correct answer is B: 20. The average human body consumes about 250 ml of oxygen per minute, and the lungs extract roughly one-fourth of this amount. Since the total cardiac output is around 5 liters per minute, and each liter of blood carries approximately 20 ml of oxygen, each 100 ml of blood leaving the alveolar capillaries would carry away roughly 20 ml of oxygen. Choice A (10 ml) is too low, as it does not account for the efficient oxygen extraction by the lungs. Choice C (30 ml) is too high, exceeding the typical oxygen-carrying capacity of blood. Choice D (50 ml) is also too high, as it overestimates the amount of oxygen carried by each 100 ml of blood.

Correct Answer: A

Rationale: If the dorsal respiratory group of neurons in the medulla oblongata were destroyed bilaterally, a person would stop breathing. This group is responsible for initiating inspiration by sending signals to the diaphragm and intercostal muscles. Without this neural input, the respiratory centers in the brainstem would not receive the necessary signals to stimulate breathing. Pulmonary ventilation would not increase markedly or the respiratory minute volume increase because the primary issue is the lack of neural drive for breathing, not an overstimulation of the respiratory system. Tidal volumes would not decrease as a direct consequence of destroying the dorsal respiratory group; it would lead to cessation of breathing altogether.

Correct Answer: A

Rationale: The correct answer is A: bronchopulmonary segment. This segment of the lung is supplied by its own tertiary bronchus, allowing for independent ventilation. Bronchopulmonary segments are functional units of the lung with their own blood supply and bronchial branches. B: Pulmonary lobule is incorrect as it refers to a small unit of lung tissue surrounded by connective tissue septa. C: Interpulmonary segment is not a recognized term in anatomy. D: Respiratory segment is not a specific anatomical term related to the lung's bronchial divisions.

Correct Answer: A

Rationale: The correct answer is A: bronchi. After entering the lungs, the trachea divides into two smaller tubes known as the bronchi, which further divide into bronchioles. The bronchi are responsible for conducting air into the lungs. Choices B, C, and D are incorrect because the trachea does not divide into another trachea, micro trachea is not a known anatomical structure, and the eustachian tube is not part of the respiratory system but instead connects the middle ear to the throat.