Histology - Digestive Tract

Question 1

oral cavity, oropharynx and laryngopharynx

Answer 1

covered by stratified squamous epithelium

generally not keratinised

Question 2

nasal cavity and nasopharynx

Answer 2

covered by respiratory epithelium

Question 3

anterior tongue -2/3

Answer 3

stratified squamous epithelium
thin on ventral surface
thick and with papillae on the dorsal surface

Question 4

posteror tongue - 1/3

Answer 4

covered by smooth stratified squamous epithelium
lacs papillae but does substantial lymphoid aggregates in the submucosa

except circumvallate

Question 5

tongue - papillae

Answer 5

fungiform
circumvallate
foliate
filiform - no tastes buds (occupy most of dorsal surface)

Question 6

entrance to oropharynx

Answer 6

pharynx includes a ring of lymphoid tissue composed of the palatine tonsils, lingual tonsils, Tuvalu tonsils and pharyngeal tonsils - adenoids

Question 7

digestive tract - IMPORTANT

Answer 7

4 major layers

MUCOSA
epithelium, lamina propria, muscularis mucosae

SUBMUCOSA EXTERNA

MUSCULARIS EXTERNA

SEROSA or ADVENTITIA

Question 8

variations in GI tract mucosa

Answer 8

mostly in mucosal layer

Question 9

gastro-oesophageal junction

Answer 9

abrupt transition from stratified squamous epithelium to simple columnar epithelium

Question 10

stomach

Answer 10

gastric pit and gastric glands

Question 11

gastric pits

Answer 11

lined by surface mucous cells

produces a specialised type of mucous - protect against acid of the stomach

Question 12

cells of the stomach epithelium

Answer 12

gastric glands not evenly distributed

isthmus - parietal cells and stem cells

neck - mucous cells and parietal cells

fundus (base) - chief cells, some parietal cells and neuroendocrine cells

Question 13

chief cell

Answer 13

digestive enzyme secreting cell

Question 14

parietal cell

Answer 14

hydrochloric acid producing cell

Question 15

stomach regions

Answer 15

mucosa differs

CARDIA - deep gastric pits that branch into loosely packed, tortuous glands

BODY - shallow gastric pits with long straight gastric glands

PYLORUS - deep gastric pits with branched, coiled gastric glands at a hight density than in the cardia

Question 16

muscularis external of the stomach

Answer 16

areas contains an additional layer

oblique to the usual circular and longitudinal muscle layers and is located interval to the circular layer

aids churning action

Question 17

gastroduodenal junction

Answer 17

abrupt transition from stomach mucosa to duodenal mucosa

inner, circular layer of smooth muscle is markedly thicken to for the pyloric sphincter

Question 18

small intestine

Answer 18

villi

between the bases of adjacent villi are pits ‘drilling’ downwards
crypts of lieberkuhn

Question 19

duodenum

Answer 19

contains Brunner’s glands in the submucosa

Question 20

jejunum

Answer 20

tallest villi, located on permanent circular folds of the mucosa and submucosa, the plicae circularis
lymphoid follicles infrequent

Question 21

ileum

Answer 21

characterised by shorted villli and aggregations of lymphoid follicles called Peyer’s patches found in the submucosa and often extending into the lamina propria

Question 22

cells of the small intestinal epithelium

Answer 22

enterocytes
goblet cells
panted cells
enterocendocrine cells 
stem cells

Question 23

cells of the small intestinal epithelium

Answer 23

enterocytes
goblet cells
panted cells
enterocendocrine cells 
stem cells

Question 24

cells of the large intestinal epithelium

Answer 24

absorptive cells

goblet cells

arranged in straight, tubular glands referred to as crypts that extend down to the muscularis mucosa

Question 25

large intestine

Answer 25

outer, longitudinal smooth muscle is distinct

not continuous but to is found in 3 muscular strips called teniaie ells

Question 26

ganglion

Answer 26

group of nerve cells living outside of the nervous system