oesophagus and stomach

Question 1

what pressure is the stomach under

Answer 1

positive

Question 2

3 key functions of stomach

Answer 2

digestion of macronutrients, storage reservoir for food until downstream organs are ready to receive stomach contents, immunological protection using strong acid

Question 3

two types of digestion

Answer 3

chemical (acid and enzymes), mechanical (mixing and churning)

Question 4

what is stomach mucosa lined with

Answer 4

columnar epithelia

Question 5

what is the stomach mucosa invaginated with and what does this contain

Answer 5

gastric pits, containing specialist exocrine and endocrine cells

Question 6

anteriorly, 5 anatomical regions of stomach

Answer 6

fundus, cardia, body, pyloric (antrum and canal), duodenum

Question 7

function of fundus and body

Answer 7

secrete HCl, mucous and pepsinogen

Question 8

function of cardia and pyloric canal

Answer 8

secrete mucous only

Question 9

function of pyloric antrum

Answer 9

gastrin secretion (stimulates acid production)

Question 10

two curvatures and relevant positions

Answer 10

lesser curvature (superior), greater curvature (inferior)

Question 11

exception of stomach wall vs other parts of digestive tract

Answer 11

extra oblique layer of smooth muscle inside circular layer

Question 12

purpose of extra oblique layer of smooth muscle

Answer 12

aids in performance of complex grinding motions (mechanical digestion)

Question 13

empty state of stomach

Answer 13

contracted

Question 14

state of mucosa and submucosa of stomach at empty state

Answer 14

thrown up into folds (rugae)

Question 15

state of mucosa and submucosa of stomach at full state

Answer 15

rugae become stretched and flat

Question 16

function of rugae

Answer 16

allow stomach to undertake reservoir function (stomach has very minor role in absorption)

Question 17

colour of stomach lining

Answer 17

bright red

Question 18

function of mucous gel lining stomach

Answer 18

provides protection against HCl, as is gel coating with HCO3- trapped in mucus gel to protect epithelial surface lining

Question 19

what invaginates into columnar epithelium

Answer 19

tubular glands

Question 20

where are mucus producing cells found

Answer 20

in neck of glands and just produce mucus

Question 21

features of peristalsis

Answer 21

20% contractions, propels chyme towards colon, more powerful as moves from LOS to pyloric sphincter; driven by ANS (centrally)

Question 22

features of segmentation

Answer 22

80% contractions, weaker, fluid chyme towards pyloric sphincter, solid chyme pushed back to body; stretching activates enteric nervous system (locally)