Which of the following stimuli activates sensors in the walls of digestive organs?

The correct choice indicates that all listed stimuli are capable of activating sensors in the walls of digestive organs. Each of these stimuli plays a role in the function and regulation of the digestive system.

Breakdown products of digestion, such as amino acids, fatty acids, and simple sugars, stimulate sensors in the digestive tract. These sensors detect the presence of these nutrients and signal various digestive processes, including enzyme secretion and absorption. This ensures that the body can effectively utilize the nutrients that have resulted from the digestion of food.

Distension, or the stretching of the walls of the digestive organs, activates mechanoreceptors in the gastrointestinal tract. This stretching occurs when food enters the stomach or intestines and signals the body to initiate processes such as peristalsis (the wave-like muscle contractions that move food through the digestive system) and secretion of digestive juices.

The pH of chyme is also a critical factor. When the acidic contents of the stomach mix with other digestive juices, sensors respond to changes in pH to regulate the secretion of bicarbonate from the pancreas and other digestive enzymes. This is important for maintaining an optimal digestive environment and protecting the intestinal lining.

In summary, all these stimuli—breakdown products of digestion, distension, and pH of