Which of the following is a characteristic of urine that indicates adequate hydration?

A. In chronic obstructive pulmonary disease (COPD), airflow obstruction leads to ventilation-perfusion (V/Q) mismatching. This means that some parts of the lungs may receive air but not enough blood flow, or vice versa, resulting in inefficient gas exchange and reduced oxygenation. This is a hallmark of COPD.

B. While COPD can eventually affect the heart, particularly leading to right heart failure (cor pulmonale), it does not directly impair cardiac output in the early stages. The primary issue in COPD is with lung function.

C. COPD does not directly impair circulation but can lead to pulmonary hypertension and strain on the circulatory system over time. However, impaired circulation is not the primary issue triggered by COPD.

D. COPD may lead to increased work of breathing, but it does not directly cause excessive cardiac demand in the same way that conditions like anemia or sepsis might.

A. Insulin is secreted by beta cells of the pancreas, not alpha cells. Therefore, a lack of alpha cells would not affect insulin secretion.

B. Alpha cells of the pancreas are responsible for secreting glucagon, which helps raise blood glucose levels by promoting the release of glucose from the liver. Without alpha cells, glucagon secretion would be impaired.

C. Somatostatin and gastrin are secreted by delta cells and G cells, respectively, not alpha cells. Therefore, a lack of alpha cells would not prevent the secretion of these hormones.

D. Pancreatic polypeptides are secreted by F cells in the pancreas, not alpha cells. Therefore, a lack of alpha cells would not affect the secretion of pancreatic polypeptides.