Physiology

Question 1

What are the 4 layers of the GI tract

Answer 1

1- mucosa
2- submucosa
3-muscularis externa
4-adventia/serosa

Question 2

What layers make up the mucosa of the GI tract

Answer 2

1- epithelium
2- lamina propria
3-muscularis mucosae

Question 3

where in the body does the submucosa of the GI tract have glands

Answer 3

oesophagus and duodenum

Question 4

Role of serosa/adventitia

Answer 4

connects organs to surrounding structures

Question 5

Where in the GI tract is it called adventitia

Answer 5

oesophagus and rectum

Question 6

Where in the GI tract is it called serosa

Answer 6

stomach, small and large intestine

Question 7

What is the parasympathetic nerve of the GI tract

Answer 7

vagus nerve

Question 8

What is the sympathetic nerve of the GI tract

Answer 8

splanchnic nerve

Question 9

Names of the plexus’ in the GI tract and where they are located

Answer 9

submucosal plexus- between submucosa and circular muscularis

myenteric plexus- between circular muscularis and longitudinal muscularis

Question 10

name of vitamin B12 deficiency

Answer 10

pernicious anaemia

Question 11

What is the anti bacterial property of saliva

Answer 11

lysozyme

Question 12

What kind of glands are saliva glands

Answer 12

exocrine as mouth is outside the body

Question 13

Which parasympathetic nerves affect salivary secretion

Answer 13

facial and glossopharyngeal

Question 14

What kind of saliva secretion does parasympathetic cause

Answer 14

very water and lots of it

Question 15

What kind of saliva secretion does sympathetic cause

Answer 15

small volume of sticky saliva

Question 16

name of movement in oesophagus

Answer 16

peristalsis

Question 17

name of folds in the stomach

Answer 17

rugae

Question 18

main function of fundus of stomach

Answer 18

storage

Question 19

main function of body of stomach

Answer 19

storage
secretion (musuc, HCl, pepsinogen, intrinsic factor)

Question 20

main function of pyloric region (antrum) of stomach

Answer 20

mixing and grinding

gastrin

Question 21

what is pepsinogen

Answer 21

inactive form of pepsin enzyme

Question 22

What stomach cell secrets mucus

Answer 22

mucus neck cell

Question 23

What stomach cell secrets HCl

Answer 23

parietal cells

Question 24

What stomach cell secrets intrinsic factor

Answer 24

parietal cells

Question 25

What stomach cell secrets pepsinogen

Answer 25

chief cells

Question 26

What enzyme combines CO2 and H2O to form carbonic acid. In which cell does this happen

Answer 26

Carbonic Anhydrase

Question 27

what molecule directly affects H+ ion secretion into lumen of stomach

Answer 27

Protein kinase

Question 28

What ion affects protein kinase activity

Answer 28

Ca

Question 29

What neurotransmitter promotes HCl production

Answer 29

acetylcholine

Question 30

What hormone promotes HCl production

Answer 30

gastrin

Question 31

What paracrine hormone promotes HCl production

Answer 31

Histamine

Question 32

What inhibits cAMP production

Answer 32

prostaglandins

Question 33

What parasympathetic nerve affects HCl production

Answer 33

vagus nerve

Question 34

Describe the 2 ways that the vagus nerve promotes HCl production in cephalic phase

Answer 34

Causes ACh to bind to receptor Stimulates g cells in pylorus region to release gastrin

Question 35

What is the cephalic phase

Answer 35

pre-emptive response (sight, smell, thought)

Question 36

During gastric phase, what stimulates vagus nerve

Answer 36

the stomach expanding

Question 37

During the gastric stage, what causes the stimulation of g cells

Answer 37

peptides in the lumen

Question 38

What releases histamine in the stomach

Answer 38

ECL cells

Question 39

What stimulates ECL cells in the gastric phase

Answer 39

ACh and gastrin

Question 40

What inhibits gastrin activity

Answer 40

low pH (lots of acid)

Question 41

What 2 things in duodenum inhibit HCl production

Answer 41

acid fat carbohydrate

Question 42

What does acid in the duodenum cause

Answer 42

enterogastric reflex and secretin release which both cause gastrin secretion to decrease and decreases parietal cell sensitivity to gastrin

Question 43

What does fat or carbohydrate in the duodenum cause

Answer 43

release of GIP which decreases gastrin secretion

Question 44

What are enterogastrones

Answer 44

hormones released by duodenum in response to acid, fatty acids, monoglycerides and hypertonic solutions

Question 45

2 main way enterogastrones work

Answer 45

inhibit gastric acid secretion | cause pyloric sphincter to close

Question 46

What causes pepsinogen to become pepsin

Answer 46

acidic environment (pH<3)

Question 47

What happens to pepsin in a neutral environment

Answer 47

becomes fully deactivated

Question 48

Mucus layer has high concentration of what molecule

Answer 48

HCO3 (bicarbonate)

Question 49

name of gastric content

Answer 49

chyme

Question 50

what causes increases peristalsis of stomach

Answer 50

gastrin increased contraction | neural control from stomach distention increases contraction

Question 51

what causes decreases peristalsis of stomach

Answer 51

fat/peptides/carbohydrate/acid/hypertonicity in duodenum

Question 52

Acid in the duodenum triggers what

Answer 52

vagus nerve and enteric nerves system to stimulate Brunner's glands s cells to secrete secretin which stimulate Brunner's cells

Question 53

What gland secretes bicarbonate in duodenum and from what layer does this gland come from

Answer 53

Brunner's gland submucosa

Question 54

What does the hormone secretin affect

Answer 54

Brunner's glands (HCO3) Pancreas (HCO3) Liver(HCO3)

Question 55

What inhibits secretin

Answer 55

neutral pH

Question 56

What part of pancreas is involved in digestion

Answer 56

exocrine

Question 57

go from smallest to largest in the travel of pancreatic secretions

Answer 57

``` acinar cells lobules intercalated ducts intralobular ducts interlobular ducts main pancreatic duct common bile duct hepatopancreatic ampulla duodenum ```

Question 58

other name for hepatopancreatic ampulla

Answer 58

sphincter of oddi

Question 59

What cells secrete digestive enzymes in the pancreas

Answer 59

acinar cells

Question 60

What cells secrete HCO3 in the pancreas

Answer 60

duct cells

Question 61

Name of inactive digestive enzymes

Answer 61

zymogens

Question 62

What converts zymogens to their active form

Answer 62

the enzyme trypsin

Question 63

Where is trypsinogen converted to trypsin

Answer 63

brush border of duodenum

Question 64

What enzyme converts trypsinogen to trypsin

Answer 64

enterokinase

Question 65

What stimulates zymogen secretion

Answer 65

cholecystokinin (CCK) | neural control

Question 66

What causes CCK release

Answer 66

fats and acid in duodenum

Question 67

what is in a portal triad

Answer 67

Hepatic portal vein Hepatic duct Hepatic artery

Question 68

What is hepatic chord comprised of

Answer 68

hepatocytes

Question 69

hepatocyte function

Answer 69

bile synthesis stores nutrients interconversion of nutrients (turns glucose to peptide or something along those lines) detoxification

Question 70

Six components of bile

Answer 70

``` Bile acids Lecithin cholesterol Bile pigment (bilirubin from red blood cells toxic metals HCO3 ```

Question 71

What component of bile is not made by hepatocytes

Answer 71

HCO3 is produced by duct cells

Question 72

What layers does the gall bladder have

Answer 72

mucosa muscularis serosa

Question 73

How does gall bladder concentrate bile

Answer 73

Na is absorbed by gallbladder, which water follows due to osmolarity

Question 74

What molecule causes relaxation of sphincter of oddi and gallbladder contraction

Answer 74

CCK (due to fat in duodenum)

Question 75

Difference between crypts and villi of small intestine

Answer 75

villi-absorption | crypts- secretion

Question 76

segmentation movement

Answer 76

like peristalsis but it goes backwards and forwards

Question 77

What cells cause segmentation

Answer 77

intestinal basic electrical rhythm (BER)

Question 78

Sympathetic nerve effect on BER

Answer 78

decrease

Question 79

Vagus effect on BER

Answer 79

Increase

Question 80

What causes peristalsis of intestine

Answer 80

Migrating Motility Complex (MMC)

Question 81

When does MMC occur

Answer 81

when absorption is complete in intestine

Question 82

Where does MMC happen

Answer 82

Antrum of stomach to distal end of ilium

Question 83

What causes MMC to stop

Answer 83

food in stomach

Question 84

What hormone is involved in MMC initiation

Answer 84

motilin

Question 85

What connects cecum and ilium

Answer 85

ileocolic sphincter

Question 86

crypts in large intestine mainly contain what cells

Answer 86

goblet cells

Question 87

Describe defecation reflex in general

Answer 87

you eat a meal this triggers mass peristalsis of colon all the way to rectum distention of rectum produced the urge to defecate

Question 88

Process of defecation

Answer 88

rectum contracts internal anal sphincter relaxes whilst external contracts increased peristalsis of colon which increases pressure on external sphincter voluntary release of faeces

Question 89

Role of acetate

Answer 89

forms fat

Question 90

Role of propionate

Answer 90

Transported to liver and undergoes glycogenesis

Question 91

Role of butyrate

Answer 91

epithelia growth and regeneration