Which muscle allows for the passage of substances from the stomach to the intestines?

The pyloric valve, also known as the pyloric sphincter, is the correct answer as it plays a critical role in regulating the passage of partially digested food and gastric juices from the stomach into the small intestine, specifically the duodenum. This muscle acts as a gateway between the stomach and the intestines, ensuring that the food is adequately processed before being released into the intestinal tract for further digestion and absorption.

The pyloric valve only opens when the stomach contents are sufficiently liquefied, allowing for a controlled and gradual release into the intestines, which helps facilitate optimal digestion and nutrient absorption.

In contrast, the lower esophageal sphincter is responsible for preventing the backflow of stomach contents into the esophagus, the rectal sphincter is involved in the control of bowel movements, and the cardiac valve does not exist in anatomical terms but may be confused with the cardiac sphincter, which is again associated with esophageal function rather than the passage of substances into the intestines.