Stomach: fundus and pylorus

Question 1

4 main regions of the stomach

Answer 1

Cardia - transitional zone between pylorus and stomach
Fundus - uppermost part
Body
Pylorus -near and opens into the small intestine

Question 2

Main functions of stomach

Answer 2

• continue digestion of carbohydrates from amylase in saliva
• creating CHYME by adding acid to injested food and churning
• secrete lipase for digestion of lipids
• secrete pepsin for digestion of proteins

Question 3

Fundus tunica mucosa

Answer 3

Forms many gastric pits lined with simple columnar epithelium. These pits invaginate into lamina propria

lamina propria contains fundus glands and lymph follicles
gastric fundic glands formed secrete mucous

muscularis mucosae

Question 4

What are the cell types of the fundus

Answer 4

Several cell types but only parietal and chief cells seen

Parietal- produce HCL, eosinophilic cytoplasm and oval nucleus, has intracellular canaliculus

Chief- Abundant RER and apical secretory granules, located in lower regions of gastric gland, basophilic cytoplasm and oval nucleus, secrete pepsinogen

Enteroendocrine cells- epithelial cells in gastric mucosa that have endocrine or paracrine functions. Some of these cells in fundus secrete serotonin.

Mucous neck cells- round nucleus and apical secretory granules, low alkaline mucous

Stem cells

Question 5

Tunica submucosa in fundus

Answer 5

richly vascularized connective tissue

Question 6

Whats special about the tunca muscularis of the fundus

Answer 6

INNER OBLIQUE LINE
middle circular
Outer longitudinal

Contains myenteric plexus of Auerbach

Question 7

What is the outer layer of fundus

Answer 7

serosa with a visceral sheet of peritoneum

Question 8

What are the main differences between the fundus and the pylorus

Answer 8

The glands in lamina propria- simple, tubular and highly branched

Gastric pits longer than fundus

cell types less: mucous cells, enteroendocrine cells, parietal

Muscularis layer has a thick inner circular layer, thin outer layer