Structure
What are the folds inside the stomach called?
Gastric folds/ rugae
What acid is secreted by the stomach?
Hydrochloric acid
What is mechanical digestion?
the physical breakdown of food into smaller particles
What is food called when it is digested in the mouth and begins to move towards the stomach?
food bolus
What is it called when the food ingested is physically changed, but not chemically?
mechanical digestion
What sphincter controls the entry of the food bolus into the stomach?
Lower esophageal sphincter
What enzyme begins protein digestion in the stomach?
Pepsin
What is the name of the wave like contractions that push food through the digestive tract?
Peristalsis
What is the main process that occurs within the stomach?
digestion
What is chemical digestion?
the breakdown of food through the use of enzymes
Which sphincter controls the exit of the chyme from the stomach to the small intestine?
Pyloric Sphincter
What substance/tool does the stomach use to protect its lining from the acidic environment?
mucous
What is the main macromolecule that is digested within the stomach?
protein
What is it called when the stomach mixes the contents with the gastric juices?
churning
What type of bond is broken during chemical digestion of proteins in the stomach?
peptide bonds
What are the four regions of the stomach?
Cardia, Fundus, Pylorus, Body
What is the inactive enzyme/precursor which is then activated into pepsin?
Pepsinogen
Why is it that protein digestion begins in the stomach?
the acidic environment of the stomach helps to denature the proteins and break them down
What are the contents of the stomach called when they leave through the pyloric sphincter?
acidic chyme
What must happen to pepsinogen before it can begin chemical digestion on proteins?
must be activated by HCl
Which layer of the stomach would you find gastric glands in?
Mucosa
Which cells are responsible for secreting hydrochloric acid?
Parietal cells
Describe how the stomach turns a food bolus into acidic chyme.
mechanical churning and chemical digestion
What keeps the digestive enzymes of the stomach from breaking down its own cells?
released in the inactive form of pepsinogen and only activated when exposed to acidic environment
Why is it important for both mechanical and chemical digestion to occur?
mechanical digestion increases the surface area, while chemical digestion breaks the food down into absorbable materials