Which muscle(s) produce(s) the movement labeled '1'?

Correct Answer: C

Rationale: The correct answer is C: external intercostals. These muscles are responsible for elevating the ribcage during inhalation, which corresponds to the movement labeled '1'. The rectus abdominis (A) is involved in trunk flexion, internal intercostals (B) aid in forced exhalation, and the diaphragm (D) primarily assists in inhalation by moving downward to increase thoracic cavity volume. Therefore, the external intercostals are the correct choice for the specific movement indicated in the question.

Correct Answer: C

Rationale: Damage to the phrenic nerves would result in the inability to fully expand the diaphragm, leading to reliance on costal breathing. This is because the phrenic nerves innervate the diaphragm, the main muscle of respiration. Without proper diaphragmatic function, the individual would have difficulty engaging in effective diaphragmatic breathing. Therefore, choice C is correct. Choices A, B, and D are incorrect because damage to the phrenic nerves would not directly impact the respiratory rate, tidal volume, or pressure differences between the lungs and the outside air. These functions are more related to overall respiratory control and lung mechanics, which are not solely dependent on the phrenic nerves.

Correct Answer: C

Rationale: The correct answer is C: to remove pathogens and debris. Alveolar macrophages are specialized immune cells located in the lungs responsible for engulfing and clearing pathogens, debris, and foreign particles. This function helps maintain lung health and prevents infections. Rationale: 1. Alveolar macrophages are part of the immune system and act as the first line of defense in the lungs. 2. Their primary role is phagocytosis, engulfing and destroying pathogens and debris to protect the respiratory system. 3. Secreting pulmonary surfactant (choice A) is the function of type II alveolar cells, not alveolar macrophages. 4. While alveolar macrophages can secrete some antimicrobial proteins (choice B), their main function is phagocytosis. 5. Facilitating gas exchange (choice D) is the role of the alveoli and not specifically of alveolar macrophages. In summary,

Correct Answer: B

Rationale: The correct answer is B: paired arytenoid cartilage. These cartilages are triangular and play a crucial role in adjusting the tension and position of the vocal cords, thus affecting voice pitch and quality. The thyroid cartilage (A) is a large shield-shaped cartilage, the corniculate cartilage (C) is small and horn-shaped, and the cricoid cartilage (D) is a ring-shaped cartilage. These cartilages do not directly influence the vocal cords' tension and position.

Correct Answer: D

Rationale: The correct answer is D because the oropharynx contains both palatine tonsils (choice A) and lingual tonsils (choice B). Palatine tonsils are located on the sides of the oropharynx and lingual tonsils are located at the base of the tongue. Pharyngeal tonsils (choice C) are also known as adenoids and are located in the nasopharynx, not the oropharynx. Therefore, choices A, B, and C alone are incorrect. Choice D is correct because both palatine tonsils and lingual tonsils are present in the oropharynx.