A patient is having her tonsils removed. The patient asks the nurse what function the tonsils normally serve. Which of the following would be the most accurate response?

Correct Answer: B

Rationale: The correct answer is B: The tonsils help to guard the body from invasion of organisms. Tonsils are part of the immune system and act as the body's first line of defense against bacteria and viruses that enter through the mouth and nose. They help to trap and kill these pathogens, preventing them from causing infections in the body. This function is essential for overall immune response and protection against illnesses. Explanation for why the other choices are incorrect: A: The tonsils do not separate the windpipe from the throat. That function is performed by the epiglottis. C: Tonsils do not make enzymes for digestion. Enzymes for digestion are mainly produced by the pancreas and salivary glands. D: Tonsils do not regulate airflow into the lungs. The epiglottis and other structures in the respiratory system are responsible for regulating airflow.

Correct Answer: A

Rationale: Step 1: The upper respiratory system requires protection and mucus secretion. Step 2: Pseudostratified epithelium provides protection and has cilia for moving mucus. Step 3: Ciliated columnar cells help sweep mucus and debris out of the respiratory tract. Step 4: Therefore, pseudostratified ciliated columnar epithelium is the correct choice. Summary: B: Moist cuboidal epithelium lacks cilia and isn't specialized for mucus clearance. C: Simple squamous epithelium is too thin and fragile for protection. D: Stratified squamous epithelium is more suited for areas with high mechanical stress.

Correct Answer: A

Rationale: The correct answer is A: 40 mm Hg. In peripheral tissues, oxygen is delivered by the blood through capillaries. The partial pressure of oxygen in the interstitial space of peripheral tissues is lower than in the blood, around 40 mm Hg. This allows for the diffusion of oxygen from capillaries to cells. Choice B (45 mm Hg) and C (50 mm Hg) are slightly higher pressures and would not promote efficient oxygen diffusion. Choice D (70 mm Hg) is closer to arterial blood oxygen levels and would not allow sufficient oxygen release to tissues. Thus, the correct answer is A as it reflects the physiological conditions necessary for effective oxygen delivery to cells.

Correct Answer: D

Rationale: The correct answer is D: oxygen-hemoglobin saturation curve. This is because the oxygen-hemoglobin saturation curve graphically depicts the relationship between the saturation of hemoglobin with oxygen and the partial pressure of oxygen. This curve helps visualize factors affecting oxygen release, such as pH, temperature, and carbon dioxide levels. A: Spirograph is a tool used for drawing geometric shapes and has no relevance to hemoglobin oxygen release. B: Pulmonary volume chart is used to measure lung volumes and capacities, not specifically related to hemoglobin oxygen release. C: Respiratory cycle chart may show breathing patterns but does not directly visualize factors affecting oxygen release from hemoglobin. In summary, the oxygen-hemoglobin saturation curve is the most appropriate tool for visualizing factors influencing oxygen release from hemoglobin, making it the correct choice over the other options.

Correct Answer: D

Rationale: The correct answer is D: Alveoli are expanded. Prior to birth, the alveoli in the lungs are collapsed, and they begin to expand and develop after birth when the baby starts breathing air. A: Pulmonary arterial resistance is high due to blood flow bypassing the lungs. B: Pulmonary vessels are collapsed to prevent blood flow in the fetal lungs. C: The rib cage is compressed in the womb due to the limited space, but it expands after birth to allow for lung expansion.