GI function

Question 1

function of the stomach

Answer 1

holding tank, regulating into intestine.

Question 2

is there any absorption that happens in the stomach

Answer 2

little net absorption of water and nutrients. alcohol and flux of some electrolytes and water.

Question 3

how many gastric phases

Answer 3

3

Question 4

what happens in the first phase of the gastric phases

Answer 4

cephalic phase - how our stomach changes when we see or smell food. stomach starts to rumble. PNS activation stimulate secretion of acids and enzymes.

Question 5

gastric phase

Answer 5

the second phase - once food is in the stomach we have muscular things that start to happen, increased mobiliity and secretion.

Question 6

intestinal phase

Answer 6

arrival of food in duodenum triggers release of hormones that block the effect of gastrin and inhibit gastric activity.

Question 7

function of the small intestine

Answer 7

absorption of water and nutrients, secretions (digestive enzymes, water and electrolytes), has a maximim absorption rate.

Question 8

why can dumping into the intestine cause stress

Answer 8

a lot can come into the intestien from the stomach and we are not able to slow the dumping down, this can cause us to lose a lot of nutrients.

Question 9

can we do anything with the nutrients from the intestines

Answer 9

no, not until we absorb it, net absorption - postive needed so more extracted than exctrted.

Question 10

function of the large intestine

Answer 10

compacting of the waste (non-digestible matter), absorption of residual water, bacterial content high (both pathogenic and symbiotic), overflow vesicle.

Question 11

how do we regulate gastric emptying

Answer 11

neural, hormonal and feedback from the intestine.

Question 12

what is the neural control of gastric emptying

Answer 12

vagal activity - stimulates motility (enhancing emptying). SNS - inhibit motility

Question 13

how can emotions effect gastric emptying

Answer 13

in neural it can stimulate or inhibit, detension of stomach enhances.

Question 14

men vs female in gastric emptying

Answer 14

found premenopausal younger women slower emptying than postmenopausal women and men of any age.

Question 15

nasogastric tube measureing

Answer 15

after giving beverage you would synerge everythig out, not so good because you cant get secretion. and not ideal.

Question 16

georges double sampling

Answer 16

drink with known conc of red dye, after time give secnd drink with more red dye. use this Vi*Ci = Vf * Cf.
fluids only, measures volume and secretion, allows for repeated measures, cheap and minimal health risk

Question 17

effect of exercise intensity on gastric emptying

Answer 17

still excrete just less then what you would do at rest, means you should still drink some stuff.

Question 18

how does gastric emptying change with carbohydrate conc

Answer 18

higher the carb percentage the slower the emptying.

Question 19

volume effects on gastric emptying

Answer 19

when you increase the volume it will increase the amount of emptying but will also increase discomfort and a larger amount of volume remians in stomach as % emptied decreases.

Question 20

solid vs liquid gastruc emptying

Answer 20

liquid much faster rate, so chopping it up will allow for a faster empty

Question 21

what kind’ve food are slow gastric empty and we therefore would want to avoid pre comp

Answer 21

higher fibre and protein/fat both delay gastric emptying.

Question 22

why does glucose polymer gastuc empty faster than just glucose

Answer 22

it has a lower osmolarity - lower particle density.

Question 23

as we increase CHO percenatge we … gastric emptying

Answer 23

decrease

Question 24

when we are worried about dehydration in exercise what may we want to do

Answer 24

have fluids that are lower in CHO

Question 25

if we are not as worried about dehydration like short intensity what can we do

Answer 25

take fluids that are higher in CHO

Question 26

other factors that influence emptying

Answer 26

nervouness, anger, stress, previous meal, temo

Question 27

how long does temperature of food affect gastric emptying

Answer 27

10 minutes, thats how long the temp will actually last.

Question 28

temp of food on gastric emptying

Answer 28

hot increase.

Question 29

nett absorption =

Answer 29

absorption - secretion

Question 30

why is intestinal absorption of water increased with sodium and CHO

Answer 30

glucose needs to be actively transported into the intestine coupled with sodium atp also needed. which opens up a tunnel for water to get pulled through aswell.

Question 31

why is there such a difference between the secretion/absorption of 17% glucose and 17% glu poly

Answer 31

17% free glucose you get nett secretion, espically in the early parts of the intestine, as you go down you will have some absorption but not heaps. poly has a lower osmolarity, nett absorption due to the type of carb osmolaorty. good for a marathon runner.

Question 32

why mix types of carbs for absorption and oxidation

Answer 32

using half fructose and half glucose will increase absorbtion and oxidation as they use different transporters and will not bottleneck. fructose is not active and slower as it does not need atp.

Question 33

how to measure blood flow in terms of GI.

Answer 33

portal vein, because what goes out is equal to what goes in.

Question 34

what can lessen the effect of less BF to the GI tract in exercise

Answer 34

CHO ingestion (fluid)

Question 35

why do 30-50% runners and triathletes have GI symptoms during exercise

Answer 35

because the large change in blood flow to the muscles and away from the GI tract.

Question 36

what is another cause of GI dysfunction

Answer 36

diet - increased fat, protein and fibre. beverages with high osmolarity.

Question 37

why is running greatest cause of GI dysfuntion

Answer 37

due to it being full body

Question 38

what can NSAIDs do the GI

Answer 38

may cause irritation, even GI tract bleeding - also decrease blood flow to kidneys.

Question 39

how can medication cause GI dysfunction

Answer 39

when it stops the contractility slowing down the gastric emptying. iron, antibiotics, h2 antagonists.

Question 40

what can exercising in the heat do to the villi

Answer 40

the villi the selective barrier - narcosis - bigger chunks can get through, that can be bad for the gut.

Question 41

why does heat stress cause endotoxemia

Answer 41

temp rises, blood to the liver gets restricted, atp depletion of the gut tissue, tight junction dysfunction enterocyte membrane damage causing dysfunction - endotoxemia.

Question 42

what does endotoxemia cause

Answer 42

cytokines - increase inflammation, increasing hyperthermia. hypertension occuring in the circulatory collpase as you struggle to get blood everywhere. then can get little pieces stuck in organs, affecting thermoregualtion and therefore performance.

Question 43

why are probiotics an aid to gut health

Answer 43

the lining of organisms themsleves are consumed in these to help the host. can be super helpful as they can enhance barrier function, helping with diarrhea, gut barrier disorders and inflammatory changes

Question 44

why is gut microbiome important

Answer 44

make a better gut boarder, they can make short chain fatty acids and byproducts from their metabolism. these can then help enhance to reduce inflammatory that could occur from the heat. so that we can have a better barrie that is not influenced byt he environmental stressors we put on it.

Question 45

the mice theory

Answer 45

two rats or mice idk. one was fat and one was lean. two different gut microbiomes. when you put them together they did not transmit any of the micros together but then when you put the lean one on the fat diet, you dont get any of the good transitter. so therefore shows us it is microbiome and diet.