Histology

Question 1

4 digestive glands

Answer 1

salivary glands, liver, gallbladder, pancreas

Question 2

main layers of the GIT inside out

Answer 2

lumen: mucosa, submucosa, muscularis externis, serosa

Question 3

layers of mucosa inside out

Answer 3

lumen: epithelium, lamina propria with glands + immune cells, muscularis mucosa

Question 4

layers of muscularis externis inside out

Answer 4

mucosa - submucosa - (oblique) - circular - longitudinal

Question 5

which 2 plexuses and where?

Answer 5

submucosal plexus in submucosa. myenteric plexus in muscularis externis

Question 6

epithelial cell type in GIT (2)

Answer 6

stratified squamous in oral cavity, pharynx, esophagus and anal canal. simple columnar for the rest: stomach, duodenum, large intestine

Question 7

muscularis externis in esophagus: voluntary?

Answer 7

upper 1/3 somatic so voluntary. lower 2/3 autonomic.

Question 8

muscularis mucosa in esophagus?

Answer 8

thick and longitudinal so that when empty, mm contracts and esophagus is closed. mm relaxes when food is present

Question 9

gastric glands in mucosa in stomach secrete 4 things?

Answer 9

mucous, pepsin, lipase, HCl –> glands are in the mucosa not the submucosa

Question 10

name of folds?

Answer 10

rugae in stomach, plicae circulares in small intestine

Question 11

gastroesophageal junction?

Answer 11

abrupt epithelial transition from stratified squamous non keratinized of esophagus to simple columnar of stomach

Question 12

ampulla of vater

Answer 12

tubes from liver/gallbladder and pancreas enter into the duodenum here

Question 13

cell types in stomach and role

Answer 13

mucus cells for mucus protection. parietal cells for HCl. chief cell for pepsin and lipase. neuroendocrine cell for GIT regulation

Question 14

small intestine cells and purpose

Answer 14

goblet cells to make mucous. enterocytes = epithelial cells; they are specialized for absoprtion and have ~3000 microvilli

Question 15

how is acidic chyme from stomach neutralized?

Answer 15

secretion from Brunner’s glands (alkaline mucus) and pancreas

Question 16

intestinal glands are also called?

Answer 16

crypts of lieberkuhn

Question 17

enterocytes turnover?

Answer 17

replaced every 3 - 5 cells: if you give meds to patient which hinders cell division, like chemotherapy, they can’t absorb nutrients as well as normal

Question 18

taenia coli

Answer 18

longitudinal muscle in the large intestine exists as these bands = intestine can expand to store feces; also aids peristalsis

Question 19

large intestine: bacteria break down?

Answer 19

fatty acids and vitamin K