HPHY 325 digestive system histology learning outcomes

how is the muscularis externa of the esophagus different from the rest of the GI tract

the upper portions of the esophagus are made of skeletal muscle and the lower are smooth muscle

function of stratified squamous epithelium in the esophagus

to protect from stomach contents or food coming down

what kind of epithelium is the gastroesophageal junction

stratified squamous--> simple columnar

what is the outermost layer of muscularis externa in the stomach

longitudinal layer

what is the middle layer of the muscularis externa in the stomach

circular layer

what is the inner most layer of the muscularis externa of the stomach

oblique layer

parietal cells in the stomach produce

intrinsic factor and HCl

chief cells in the stomach produce

pepsinogen and gastric lipase

mucous cells in the stomach produce

bicarbonate rich alkaline mucous

enteroendocrine cells in the stomach produce

gastrin

function of intrinsic factor

aids in vitamin B12 absorption

function of HCl in the stomach

kill ingested microorganisms, hydrolyze substances, activate pepsin enzyme

function of pepsinogen

activated to pepsin to digest proteins

function of gastric lipase

hydrolyzes triglycerides into fatty acids and monoglycerides

function of bicarbonate in the stomach

Buffers acid chyme

function of alkaline mucous in the stomach

- Protects lining of stomach from HCL

- Helps neutralize acid that enters the duodenum from the stomach.

function of gastrin

Increases gastric motility and stimulate gastric secretion

features of duodenum

intestinal glands in the mucosa

duodenal glands in the submucosa

features of the jejunum

longer villi

nothing in the submucosa

features of the ileum

peyers patches

goblet cells

function of peyers patches

immune function

function of duodenal glands

secrete alkaline mucus to neutralize acidic chyme

function of intestinal crypts

continual stem cell division producing new epithelial cells, and hormone and enzyme production

what way does food travel in the recto-anal junction

simple columnar-->stratified squamous

why is there more goblet cells in the large intestine

to protect the epithelium from fecal matter

what structures make up the portal triad

portal venule, hepatic arteriole, bile duct

where is blood in the hepatic arteriole coming from

hepatic artery

where is blood in the hepatic portal venule coming from

GI tract

where is bile in the bile duct coming from

the liver

what is the function of stellate macrophages

engulf pathogens, cell debris, and damaged blood cells in the liver

what cells contribute to exocrine function in the pancreas

acinar cells

what cells contribute to endocrine functions in the pancreas

alpha and beta cells