Vitamin K deficiency result in:

Correct Answer: B

Rationale: Vitamin K deficiency causes bleeding manifestations (B) lacking K impairs factors II, VII, IX, X synthesis, prolonging PT (e.g., >15s), causing bruising, epistaxis. Spoon nails (A), alopecia (C), fissured tongue (D) tie to iron or B12. Jaundice fits liver failure, not K alone. Bleeding is key, guiding nursing for vitamin K injection and monitoring INR.

Correct Answer: C

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: D

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: A

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: B

Rationale: Pulmonary vascular resistance (PVR) is the resistance to blood flow through the pulmonary circulation, influenced by lung volume and vessel mechanics. At high lung volumes (e.g., near total lung capacity), extra-alveolar vessels are stretched and narrowed due to lung expansion, increasing PVR, while alveolar capillaries are compressed, further elevating resistance. Conversely, at low lung volumes (e.g., near residual volume), extra-alveolar vessels are less stretched and more open, and alveolar capillaries are less compressed, resulting in lower PVR. Thus, PVR is lowest at low lung volumes, making that statement true. Increased PVR, as seen in conditions like pulmonary hypertension or fibrosis, can indeed strain the right heart, leading to failure (cor pulmonale), but this is not the focus of the true statement query. PVR is not measured by routine pulmonary function tests (e.g., spirometry), which assess airflow and volumes, not vascular pressures; it requires invasive methods like cardiac catheterization. The statement about low PVR at low lung volumes reflects the physiological relationship between lung volume and vascular caliber, where resistance is minimized when the lungs are less expanded.