GIT

Question 1

name the processes involved in propulsion and mixing of food

Answer 1

trituration - reduces food particle size

grinding - bolus trapped near antrum is churned

retropulsion - particles > 2mm returned to corpus

persistalisis - (not in colon) wave of relaxation followed by contraction

segmenting movements - random churning movements

interdigestive migrating motor complex - three phates
1 - no movement
2 - random segmenting movements
3 - intestinal house keeper sweeps from oesophagus tp ileum to clear small int.

Question 2

what do the following cells secrete?

parietal/oxyntic
ECL
G cells
chief cells

Answer 2

HCl and IF (food breakdown and B12 absorption)
histamine (stim parietal cells)
gastrin (stim ECL and parietal)
pepsinogen (breaksdown protein)

Question 3

what makes up musocal barrier functions?

Answer 3

mucus - combines with water, phospholipids and electrolytes to create gel layer

Bicarb - secreted by epi cells. is trapped under gel layer.

tight junctions - prevents diffusion of H and pepsin

Prostoglandin synthesis - inc bocarb, mucus, blood flow, epithelial prolif. Reduces H.

Microcirculation - enables prolif of epi

Question 4

Brunners glands are specific to where in gut?

Answer 4

duodenum. secretes bicarb and alkaline mucus layer.

Question 5

foregut, midgut and hindgut are supplied by which arteries?

Answer 5

fat children make super happy idiots
fore - coeliac
mid - superior mesenteric
hind - inferiot mesenteric

Question 6

what enzymes does the pancreas secrete to digest proteins?

Answer 6

trypsin - activated by enteropeptidase. can then self activate and activates the others…
chymotrypsin
elastase
carboxypeptidases A and B

Question 7

how are carbs digested?

Answer 7

ptyalin alpha amylase in saliva - 20-40%
is deactivated in the stomach
small intestines receive alpha amylase from the pancreas - 50-80%.

lactase, sucrase and maltose convert lactose, sucrose and maltose into smaller sugars.

Question 8

how are sugars absorbed?

Answer 8

all absorbed as monosacharides.
Apical SGLTI glucose/Na symporter
GLUT5 fructose transporter
BL GLUT2

Question 9

how are fats digested and absorbed?

Answer 9

linguinal lipase secreted by Von Ebners glands in mouth startes it off.

Chyme enters duo - secretin is released - stim bicarb rel from pancreas to reduce pH to 6.5 - optimal for fat digestion.

bile salts released due to CCK. emulsification.

Micelles formed. Enable FA’s to be delived to enterocytes.

SER form TAGs, Chylomicrons package and into lymph

Question 10

decreased folate and B12 indicates what?

Answer 10

total intestinal involvement of malabsorption - crohn’s or coeliacs

Question 11

increased folate but decreased B12 indicates?

Answer 11

bacterial overgrowth

Question 12

name the breath tests used to assess malabsorption

Answer 12

C14 triolene - fats - releases CO2 when metabolised - indicates capacity to absorb fat.

Hydrogen - lactose - increased if malabsorption present

D-xylose - carbs- measures radiolabeled CO2 indicates absroprion ok. Can show diffuse small int disease and bacterial OG.

Question 13

What does to schilling test show you?

Answer 13

B12 malabsorption due to bacterial overgrowth, pancreatic failure, pernicious anemia.

involves IM inj of labelled B12 and normal B12, urine levels of labelled B12 measured. If <8% = malabsorption

Question 14

the enteric plexus has 2 branches, they are?

Answer 14

mucosal plexus - sample lumen of gut and communicate with axons in lamina propria of villi

myenteric plexus - muscle movement

Question 15

gut pain is mediated by?

Answer 15

spinal afferent pathways (no vagal or enteric sensory)

poorly localised. initiated by distension, spasm, inflam, ischaemia, chemical damage.

Question 16

the rectus sheath is made up of what?

Answer 16

anterior and posterior parts above the arcuate line, onlyu anterior below arcuate line.

anterior = ext and int oblique aponeurosis above line, below it includes the transversus abdominus..

posterior = int ob ap and trans abdominus

Question 17

direct inguinal hernias, more common in?

pass through where?

Answer 17

older men
abdominal contents pass through superficial inguinal ring (through external oblique aponeurosis) but NOT the deep.

Hesselbachs triangle is an area of weakness a direct hernia may pass through.

Question 18

indirect hernias more common in?

pass through?

Answer 18

younger men with a patent process vaginalis.

passes through deep (formed from the transversalis fascia) and superficial inguinal canals.

Question 19

what does the inguinal contain?

Answer 19

spermatic cord and ilioinguinal nerve

spermatic cord has 3 covering layers and 6 contents:
1 - external spermatic fascia
2 - cremasteric fascia and muscle
3 - internal spermatic fascia

vas def
testicular artery
veins
lymph
nerves (genital b. of gen fem)
processus vaginalis

Question 20

C. difficile is linked to?

Answer 20

antibiotic use, hospitals, PPI’s

Question 21

amebiasis is linked to?

Answer 21

travel to endemic areas. faecal oral route. dirty water (washing fruit and salad)

Question 22

what food poissoning is linked to meat, cream or salad?

Answer 22

staphlococcus aureus

Question 23

what bug is linked to rice and milk?

Answer 23

bacillus cereus

Question 24

bugs related to seafood?

Answer 24

shigella
V. cholerae
V. paraheamolyticus

Question 25

canned food bug?

Answer 25

clostridium botulinum

Question 26

meat and gravy bug?

Answer 26

clostridium perfingens

Question 27

noro and rota virus are associated with what?

Answer 27

daycare, cruiseships