upper GIT

Question 1

why chew

Answer 1

prolong taste experience

defence against resp failure

Question 2

what is saliva secreted by

Answer 2

3 pairs of salivary glands

• parotid
• submandibular
• sublingual

Question 3

what’s in saliva

Answer 3

water
mucins
alpha-amylase
electrolyes
lysozyme

Question 4

how is salivary secretion controlled

Answer 4

parasympathetic and sympathetic NS

both stimulatory

Question 5

control saliva secretion: parasympathetic

Answer 5

facial and glossopharyngeal nerves

stimular profuse watery salivery secretion

Question 6

control saliva secretion: sympathetic

Answer 6

small volume, viscous salivary secretion

high mucus content (alpha-1 adrenoceptors)

high amylase content (beta-2 adrenoreceptors)

Question 7

reflex control of saliva secretion

Answer 7

presence of food in mouth –> chemoreceptors/pressure receptors (walls of mouth/tongue)

Question 8

how long is oesophagus

Answer 8

approx 25cm

Question 9

oseophagus - type of epithelium

Answer 9

stratified squamous epithelium (non-keratinised)

Question 10

muscularis externa - what type of muscle

Answer 10

upper 1/3 - skeletal

lower 2/3 - smooth

Question 11

swallowing - oral phase

Answer 11

bolus pushed back to back of mouth by tongue

Question 12

swallowing - pharyngeal phase

Answer 12

prescence of bolus - reflex contractions of pharyngeal muscles (coordinated by swallowing centre)

soft palate reflected backward and upwards (close of nasopharynx)

Question 13

swallowing - as bolus approaches oesophagus

Answer 13

UOS relaxes and epiglottis covers opening to larynx

Question 14

swallowing - once food enters oesophagus

Answer 14

UOS contracts to prevent food reflux

Question 15

swallowing - oseophageal phase

Answer 15

propulsion bolus to stomach

peristaltic waves

Question 16

swallowing - as bolus nears stomach

Answer 16

LOS relaxes - bolus enters stomach

Question 17

functions of stomach

Answer 17

temp store of ingested material
dissolve food particles and initiate digestive process
control delivery of contents to small intestine
sterilise ingested material
produce intrinsic factor

Question 18

regions of stomach

Answer 18

cardiac region 
fundus 
body (greater + lesser curvature) 
pyloric region
pyloric opening/sphincter

Question 19

stomach histology: muscularis externae

Answer 19

3 layers

longitudinal
cirucler
oblique

Question 20

stomach histology: lumenal surface

Answer 20

surface mucus cells
gastric pits
gastric glands - mucus neck cells, parietal cells, cheif cells

Question 21

cells in gastric glands

Answer 21

mucus neck cells
parietal cells
cheif cells