Digestive Processes and Regulation

Ingestion

Food is chewed and mixed with saliva that begins the breakdown of carbs and lipids through lingual lipase

Propulsion

• act of swallowing

• refers to the movement of food through the alimentary canal

Peristalisis

• Contraction and relaxation of alimentary canal smooth muscle to move food along

• works to also mix ingested materials with digestive jucies

Mechanical digestion

an entirely physical process that does not change the chemical make up of food

makes food smaller as well as increasing surface area

Mastication

chewing

Examples of mechanical digestion

• churning of food in the stomach

• contractions of the muscularis in the small intestine

Chyme

acidic stomach juice

Segmentation

Localized contractions of the muscularis in the small intestine that moves food back and forth in the circular rings

Chemical digestion

It begins in the mouth and is digestive secretions breaking down complex food molecules into their chemical building blocks

Make up of digestive secretion

water, enzymes, acids, and salts

Absorption

Primarily takes place in the small intestine and is the absorption of nutrients into the blood stream

Defacation

pooping

Gastrin

Stimulated in response to the presence of food to release gastric juices in the stomach

Secretin

Produced by the duodenum to produce bicarbonate from the pancreas

cholecystokinin (CCK),

stimulates the secretion of pancreatic enzymes and bile from the liver and release of bile from the gallbladder;

gastric inhibitory peptide,

which inhibits gastric secretion and slows gastric emptying and motility.

endocrinocytes,

located in the mucosal epithelium of the stomach and small intestine. These hormones then enter the bloodstream, through which they can reach their target organs.

These GI hormones are secreted by specialized epithelial cells,