General GI

Question 1

`steatorrhoea

Answer 1

passage of pale bulky stools that contain fat + indicates fat malabsorption as a result of small bowel, pancreatic disease or cholestatic liver/biliary disease

Question 2

a feacal marker of intestinal inflammation + tissue damage

Answer 2

feacal cal protein

Question 3

what does OGD stand for

Answer 3

oesophagogastroduodenoscopy, ‘gastroscopy’

Question 4

how to investigate the small bowel? given that its so long

Answer 4

balloon-assisted enteroscopy

video (wireless) capsule endoscopy

Question 5

what are oral white patches associated with

Answer 5

smoking, candida infection, lichen plants, trauma + syphilis

Question 6

what may cause a smooth sore tongue with loss of filiform papillae?

Answer 6

vit b12 deficiency

Question 7

what may cause mouth dryness?

Answer 7

anxiety, drugs such as tricyclic anti-Ds, Sjogren’s syndrome + dehydration

Question 8

whats dysphagia?

Answer 8

difficulty swallowing

Question 9

achalasia

Answer 9

a motility disorder

muscles of the lower part of the oesophagus fail to relax, preventing food from passing into the stomach

Question 10

Odynophagia

Answer 10

pain during swallowing particularly with alcohol and hot liquids

suggests oesophagitis due to GORD, infections of the oesophagus to drugs such as slow release potassium or bisphosphonates

Question 11

Muscle type distribution in the oesophagus

Answer 11

pros 3rd = skeletal –> mixed –> smooth

Question 12

What phase of swallowing is it when the soft palate closes of the nasopharynx and elevation of the hyoid bone shortens and widens the pharynx?

Answer 12

Phase 2: involuntary

Question 13

whats the voluntary phase of swallowing?

Answer 13

the 1st phase.

the tongue compresses food against the roof of the mouth + pushes it towards the oropharynx

Question 14

in swallowing, what phase is it when the constrictor muscles sequentially contact, and what’s it followed by?

Answer 14

phase 3: involuntary

the 2nd part of this phase is the return/depression of the hyoid bone and pharynx

Question 15

whats the gag reflex?

Answer 15

elevation of the pharynx
caused by irritation of the oesophagus
reflex arc between IX (sensory) and X (motor)

Question 16

4 functions of saliva

Answer 16

1. contains mucus
2. amylase
3. dissolves
4. antibacteria

Question 17

what type of acini have a small central duct and what do they secrete?

Answer 17

serous acini

water and alpha-amylase

Question 18

what connects acini to larger striated ducts?

Answer 18

intercalated interlobular ducts

Question 19

which gland does the facial nerve pass through?

Answer 19

the parotid

Question 20

which nervous system stimulates salivary secretion?

Answer 20

parasympathetic nervous system

Question 21

BMR

Answer 21

metabolic rate when a person is at mental + physical rest but not sleeping. at a comfortable temp
fasted at least 12 hrs

Question 22

functions of the stomach

Answer 22

storage
mixing
dissolving
continuing digestion
regulate emptying
kill microbes
secrete + lubrication

Question 23

PC HIP pneumonic for stomach cell secretions

Answer 23

Parietal cells secrete HCl and IF

Chief cells secrete pepsinogen

Question 24

where are chief cells located? (stomach)

Answer 24

F + B + P

Question 25

which cell type is located just in the fundus and body of the stomach

Answer 25

parietal cells

Question 26

which stomach cells secrete gastrin?

Answer 26

``` enteroendocrine cells (G cells) located in the antrum ```

Question 27

which cells secrete histamine

Answer 27

ECL cells

Question 28

what do D cells secrete?

Answer 28

somatostain

Question 29

mediators of acid secretion

Answer 29

ACh - increases Gastrin - increases Histamine - increases Soamtostain - decreases

Question 30

what does the vagus nerve secrete (stomach)

Answer 30

ACh

Question 31

cephalic phase

Answer 31

sight, smell taste and chewing lead to ACh release ACh (enteric) acts directly on parietal cells also triggers gastrin + histamine release

Question 32

what happens in the gastric phase

Answer 32

1. gastric distension, presence of peptides and AAs increases HCl secretion (gastrin + histamine release, and somatostatin inhibiton) 2. low luminal pH inhibits gastrin directly. also stimulates somatostatin release, indirectly inhibiting parietal cells

Question 33

intestinal phase

Answer 33

duodenal distension, low luminal pH, hypertonic contents and AA/FA presence lead to CCK and secretin release as well as neural reflexes

Question 34

what are enterogastrones and what do they lead to?

Answer 34

CCK and secretin are. they increase pancreatic exocrine secretion

Question 35

what does somatostatin turn off?

Answer 35

the process of forming proton pumps that gastrin, histamine and ACh stimulate via 2nd messengers

Question 36

what parallels the secretion of HCl?

Answer 36

pepsinogen - its also mediated by ACh

Question 37

what does pepsin come from?

Answer 37

when pepsinogen is activated in acidic conditions pepsin also catalyses its own production - +ve feedback loop

Question 38

function of pepsin?

Answer 38

breaks protein down into peptides

Question 39

how is pepsin inactivated?

Answer 39

irreversibly by HCO3- in the small intestine

Question 40

what increases gastric peristaltic waves?

Answer 40

gastrin and gastric distension

Question 41

what decreases gastric peristaltic waves?

Answer 41

duodenal distension, duodenal fat, osmolarity, decrease pH, increased sympathetic drive

Question 42

function of the duodenum

Answer 42

mixes stomach contents, bile and pancreatic exocrine secretions

Question 43

3 important duodenal secretions

Answer 43

mucus (Brunner's gland), CCK and secretin

Question 44

what does jejunum absorb?

Answer 44

actively: glucose, AAs, small peptides, vitamins passive: fructose

Question 45

what does the ileum absorb?

Answer 45

bile salts, B12

Question 46

where is calcium actively absorbed?

Answer 46

duo + jej

Question 47

how is ileum different to jej?

Answer 47

payer's patches and more mesenteric fat

Question 48

2 types of motility in small intestine

Answer 48

segmentation | peristalsis

Question 49

function of large intestine?

Answer 49

to complete absorption of water + few remaining carbs movement: contraction in the circular muscle

Question 50

how and where is vitamin b12 absorbed?

Answer 50

in the terminal ileum after pairing with IF

Question 51

where is folate absorbed? | where is iron absorbed?

Answer 51

folate - jejunum | iron - duodenum

Question 52

what do bile salts to do fat?

Answer 52

emulsify them into emulsion droplets

Question 53

what does lipase break down?

Answer 53

breaks down emulsion droplets into free FAs and bile salts, which then combine to form micelles

Question 54

where are micelles formed into chylomicrons?

Answer 54

in enterocyte cells, for transport in blood - released by exocytosis

Question 55

what does lipoprotein lipase do?

Answer 55

breaks down triglycerides in chylomicrons into fatty acids and glycerol in the capillaries

Question 56

what's CCK and what stimulates it?

Answer 56

cholecystokinin | stimulated in the presence of fat in the duodenum, to release bile from GB and pancreatic enzymes from the pancreas

Question 57

2 nerve plexuses of the intestine

Answer 57

Meisneer's - submucosal | Auerbach's (myenteric)