The nurse is caring for a client thought to have lobar pneumonia. Which color does the nurse anticipate the sputum to be when obtaining a sputum sample?

Correct Answer: B

Rationale: Rust-colored sputum (B) is expected in lobar pneumonia, typically from Streptococcus pneumoniae, as hemoptysis results from RBC breakdown in consolidated alveoli. Brown (A) suggests old blood or fungal infection (e.g., Aspergillus), not classic lobar. Red (C) indicates fresh bleeding, rare unless necrotizing. Cloudy (D) is purulent (e.g., bronchopneumonia), not specific to lobar's bloody hue. The document's answer (B) matches pathology S. pneumoniae's virulence causes capillary leakage, yielding 'rusty' sputum, a hallmark distinguishing it from A's chronicity or D's infection type.

Correct Answer: A

Rationale: Alveoli are the tiny air sacs in the lungs, numbering about 500 million, where gas exchange occurs oxygen enters the blood, and carbon dioxide exits via diffusion across their thin walls. The bronchus (singular) and bronchioles are airways leading to alveoli, not sacs themselves bronchi branch from the trachea, and bronchioles are smaller terminal passages. 'All' is incorrect; only alveoli fit the description. Their vast surface area (about 100 m²) and capillary network make them the lungs' functional units, essential for oxygenation, a key focus in respiratory anatomy and diseases like emphysema, where alveoli degrade.

Correct Answer: A

Rationale: In birds (Aves), gas exchange occurs in the lungs, not air sacs. Their unique system features rigid lungs with parabronchi, where oxygen and carbon dioxide diffuse into blood continuously, unlike human tidal breathing. Air sacs act as bellows, moving air unidirectionally through the lungs, but lack capillaries for exchange they store and pump air. 'Air sacs and lungs' overstates sacs' role; 'none' is wrong lungs are key. This efficient design supports high metabolism for flight, a distinct adaptation in avian respiration, critical for understanding comparative physiology and bird-specific respiratory conditions.

Correct Answer: B

Rationale: The anterior interventricular sulcus, a groove on the heart's front surface, marks the boundary between the right and left ventricles, housing the anterior interventricular artery. The coronary sulcus encircles the heart, separating atria from ventricles. The posterior interventricular sulcus, on the back, also divides ventricles but is less prominent anteriorly. The coronary sinus is a vein, not a groove. This sulcus's visibility and vascular role make it a key landmark, guiding surgical and imaging approaches, essential in cardiac anatomy for locating ventricular divisions.

Correct Answer: C

Rationale: Gap junctions electrically connect cardiac muscle fibers, allowing rapid ion flow between cells via connexin channels, synchronizing contractions across the myocardium for a unified heartbeat. Desmosomes anchor fibers mechanically, not electrically. Tight junctions seal cells, rare in heart tissue. Interneurons are neural, not muscular. These gap junctions, within intercalated discs, enable the heart's autorhythmic, coordinated action, a key feature distinguishing cardiac from skeletal muscle, essential in physiology and arrhythmias where connectivity falters, disrupting rhythm.