the stomach

In the stomach both_____digestion occur

mechanical (churning) and chemical (continued digestion of carbs and initial digestion of proteins and tryglycorides0

4 main regions of the stomach:

• cardia

• fundus

• body

• pylorus

cardia

• cardiac region

• the point where the esophagus connects to the stomach

fundus

• dome shaped

• above left to cardia

body

• main part of stomach

• below fundus

plyorus

• funnel shaped

• connects the stomach to the duodenum

plyoric antrum

• wider end of the funnel

• connects to the body of the stomach

plyoric canal

• narrower end of the funnel

• connects the body to the duodenum

plyoric sphincter

• located at the connection point of body and duodenum

• controls stomach emptying

ruga

when the stomach is empty it deflated inwards and its mucosa and submucosa fall into a large fold called the _____

The stomach is held in place by the ____

greater and lesser omentum

The stomach wall is made of ______

the same 4 layers as the rest of the alimentary canal

The adaptations to the mucosa and muscularis are___

• an inner oblique smooth muscle layer in the muscularis as well as the circular and longitudinal muscle layers

The stomach mucosa’s epithelial lining consists of____

only surface mucus cells that secrete a protective coat of alkaline mucus

gastric pits

• dot the surface of the epithelium

• mark the entry to each gastric gland

gastric gland

secret a complex digestive fluid (gastric juice)

The glands of the cardia and pylorus are composed of mostly ______

mucus-secreting cells

Cells in the plyoric antrum____

secrete mucus and multiple hormones (gastrin most importantly)

The glands of the fundus and body are_____

much larger and the site of most chemical digestion, produce most of the gastric secretions

The glands of the fundus and body are made up of secretory cells like______

parietal,chief, mucous neck, and enteroendocrine cells.

Parietal cells

• most highly differentiated of the body’s epithelial cells

• located primarly in the middle region of gastric glands

• relatively large

• produce hydrochloric asid and intrinsic factor

Hydrochloric acid (HCl)

• responsible for the high acidity of the stomach (pH 1.5-3.5)

• needed to activate the protein digesting enzyme pepsin

The acidity of the stomach _____

• kills most of the ingested bacteria

• helps to denature proteins, making them more avalible for enzymatic digestion

Intrinsic factor

• glyco protein necessary for the absorption of vitamin B12 in the small intestine

Chief cells

secrete pesinogen

pepsinogen

• the inactive form of proenzyme form of pepsin

• HCl is necessary for the conversion of pepsinogen to pepsin

mucous neck cells

secrete thin acidic mucous that is different from regular mucous produced by goblet cells

purpose of mucous not know

enteroendocrine cells

• secrete various hormones into the interstitial fluid of the lamina propria

enteroedocrine G cells

release gastrin