EX. 38 Histology- Digestive System (tooth, stomach, esophagus/stomach junction, pancreas, duodenum+jujuneum, ilium, colon/large intestine)

top portion

crown

lower section around tooth

gingiva (gums)

• stratified, good for protection

lower section of tooth

root

stomach wall

mucosa (stomach wall)

submucosa (stomach wall)

muscularis externa (stomach wall)

serosa (stomach wall)

mucosa (stomach wall)

submucosa (stomach wall)

muscularis externa

simple columnar epithelium (mucosa layer)

lamina propria (mucosa layer)

gastric pit (mucosa layer)

gastric glands (mucosa layer)

esophagus-stomach junction (now zoomed in)

• esophagus: stratified squamous cells for protection as you are swallowing,

• stomach: simple columnar cells for digestion and easy secretion (gastric pits and mucosa layer)

stratified squamous epithelium of the esophagus

esophagus-stomach junction lm

simple columnar epithelium of the stomach

pancreas

• endocrine: islets- beta cells (insulin producing) alpha cells (glucagon producing)

• exocrine: acinar cells secrete digestive enzymes (lipase, amylase, sodium bicarbonate) to be dumped into duodenum

duodenum

mucosa (duodenum)

submucosa (duodenum)

muscularis externa (duodenum)

• specifically circular layer

muscularis externa (duodenum)

• specifically longitudinal layer

serosa (duodenum)

• contains fat

white cells

goblet cell (duodenum)

• secretes mucus

dark cells

nucleus of simple columnar cells in duodenum

circular fold (jejunum)

villi (jejunum)

villus (singular)- jejunum

connective tissue that absorbs nutrients in jejunum

• may be absorbed by capillaries or lacteals!

mucosa (jejunum)

submucosa (jejunum)

muscularis externa (jejunum)

serosa (jejunum)

villus (duodenum)

simple columnar epithelium (duodenum)

lamina propria (duodenum)

ileum

peyers patches (ileum)

• lymphoid tissue (contains lymphocytes, macrophages, and dendritic cells

• immune tissue

mucosa (ileum)

submucosa (ileum)

muscularis externa (ileum)

serosa (ileum)

villus (ileum)

submucosa (ileum)

• contains peyers patches

peyers patches (ileum)

muscularis externa (ileum)

large intestine/ colon

• lots of goblet cells for water reabsorption for easy movement of feces along with mucus

• vili are more organized

mucosa (large intestine/colon)

submucosa (large intestine/colon)

• connective tissue

muscularis externa (large intestine/colon)

• circular layer

• longitudinal layer

serosa (large intestine/colon)

lumen (large intestine/colon)

goblet cells in epithelium (large intestine/colon)

lamina propria (large intestine/colon)

muscularis mucosae (large intestine/colon)

submucosa (large intestine/colon)