The nurse is instructing a group of college students about the signs and symptoms of 'walking pneumonia.' Which manifestation should the nurse include? (Select all that apply.)

Correct Answer: B

Rationale: Walking pneumonia' (atypical, e.g., Mycoplasma) includes headache (B), fever, muscle aches, and joint pain per the document. Productive cough (A) is less common dry cough predominates. Headache (B) reflects systemic inflammation from mild infection, allowing ambulation. Fever (C) is low-grade, muscle aches (D) and joint pain mimic flu, per nursing texts. B's prominence in teaching aligns with atypical presentation subtle systemic signs distinguish it from A's wet cough.

Correct Answer: B

Rationale: External respiration is the exchange of gases oxygen in, carbon dioxide out between the external environment and the lungs, occurring in the alveoli where air meets blood. 'Respiration' broadly includes this plus cellular processes, too vague here. Cellular respiration is intracellular, using oxygen to produce energy, not lung-based. 'None' is wrong external respiration fits precisely. This process involves air entering via inhalation, diffusing across alveolar walls into capillaries, and CO2 exiting, driven by partial pressure gradients. It's the lungs' primary role, distinct from internal or cellular phases, a critical distinction in respiratory physiology for gas transport understanding.

Correct Answer: A

Rationale: Earthworms respire through their skin, a moist, permeable surface allowing oxygen to diffuse into blood vessels beneath and carbon dioxide to exit no lungs or specialized organs exist. The head isn't a respiratory focus; respiration spans the body. Lungs are absent earthworms lack a respiratory tract. Anterior pores misrepresent skin diffusion, which occurs across all segments. This cutaneous respiration requires dampness, as oxygen dissolves in mucus, a simple yet effective adaptation for soil-dwellers, contrasting with complex lung systems, a key comparative physiology insight.

Correct Answer: A

Rationale: Heart valves are made of dense connective tissue, primarily collagen, providing strength and flexibility to withstand pressure changes, with a core of fibrous tissue layered by endothelium. Areolar connective tissue is loose, not robust enough. Hyaline cartilage is rigid, found in the trachea, not valves. Cardiac muscle forms the heart wall, not valves. This dense tissue, avascular and resilient, ensures durability cusps flex without stretching key in valve function, relevant in pathology like calcification where flexibility diminishes, impacting flow.

Correct Answer: D

Rationale: The cardiac action potential follows: SA node (pacemaker, initiates), AV node (delays signal), bundle of His (transmits to ventricles), Purkinje fibers (spreads to ventricular myocardium), driving normal contraction. Other sequences disrupt this flow e.g., starting with Purkinje or misordering AV node delays atrial-ventricular timing. This precise path, from SA node atop the right atrium to Purkinje's ventricular reach, ensures atria contract before ventricles, optimizing filling and ejection, a fundamental rhythm in cardiac physiology, disrupted in arrhythmias like bundle branch block.