Question

Choice E: Explain the difference among a digestive reflex, digestive hormone, and digestive enzyme. Give an example of each and list the conditions under which each one would occur. Can you think of an example where a digestive reflex and a digestive hormone are redundant (have the same effect)?

Answer 1

The physiological reflex that controls the mobility, or peristalsis, of the gastrointestinal tract. It helps to increase in motility of the colon in response to stretch in the stomach. It function in driving existing intestinal contents through the digestive system. Short reflexes to the digestive system provide shortcuts for the enteric nervous system(ENS) to act quickly. The enterogastric reflex is stimulated by the senses. This reflex releases acid in the duodenum or in the stomach, and suppresses the release of digestive proteins.  

There are three ovearching reflexes that control the movement, digestion, and defecation of food and food waste:

1. The enterogastric reflex

2. The gastrocolic reflex

3. The gastroileal reflex

There are 3 main digestive hormones that regulate digestion:

* Gastrin cholecystokinin family- gastrin and cholecystokinin

* Secretin family- secretin, glucagon, vasoactive intestinal peptide and gastric inhibitory peptide

* Somatostatin family

* Substance P.

* Motilin family.

Digestive enzymes : A group of enzymes that break down polymeric, secreted in the stomach and the intestine. Gastrin which signals the secretion of gastric acid. Cholecystokinin, which signals the secretion of pancreatic enzymes. Secretin, which signals secretion of water and bicarbonate from the pancreas. Ghrelin, which signals when we are hungry.