Lecture 2 pptx Flashcards
gastrin Is secreted by ____ stimulates ____ Production and also stimulates secretion of _____ in the stomach
Stomach
HCL
Pepsinogen
secretin is secreted by which organ? and does what?
Small Intestine
Stimulates water and Bicarbonate secretion in pancreatic juice
CCK is secreted by which organ? and does what?
SI
secreting of enzymes into PJ
Gallbladder contractions
inhibits gastric motility
GIP ( gastric inhibitory peptide ) is secreted by which organ? and does what?
Small I
inhibits gastric motility and secretion
Glucogon like peptide 1 (GPL1)is secreted by which organ? and does what?
Illeum and colon
inhibits gastric motility and secretion
Guanylin is secreted by which organ? and does what?
Illeum and colon
causes removal of NaCl and water from feces
True or false. Gastrin and CCK compete for binding on Lower Esophageal Sphincter receptors.
True
True or false. Gastrin and CCK compete for binding on lower esophageal sphincter
receptors
True. They have opposite functions on the esophagus
Sucrose is disacch, comprised of which two sugars?
Sucrose -> glucose –fructose
Lactose
is disacch, comprised of which two sugars?
-> glucose –galactose
Which one of these can cross the intestinal Lumen ( passively)? i. Proteins ii. Tripeptides, iii. dipeptides iv. LCFA v. MCFA a all of the above b.i, v, c. ii, iii iv d ii, iii, v
d.
How are Fats broken down and absorbed through the lumen?
- Bile salts emulsify fatty acid droplets into smaller ones in the small intestine
- lipase released from the pancreas breaks down fat into FA, diaglerols, monoacyglycerol
- micelle encapsulates these bad bois for transport across the lumen
Most absorption of vitamins occurs in the ______ and _________. Does it occur by active transport or diffusion?
jejunum and ileum
Diffusion
Fat-soluble vitamins are?
A, D, E, K
Water-soluble vitamins are?
B vitamins and C
T or F B12 is water soluble therefore it can be absorbed easily though the lumen?
False. It requires IF (intrinsic factor; binding factor) to pass through epithelial wall to the blood stream
Intrinsic Factor is secreted by and is important for what?
secreted by gastric mucosa. It’s
folic acid requres which enzyme to be synthesized
Folic acid requires intestinal enzyme conjugase
True or false. minerals are generally well-absorbed in the intestine
False. Little absorption ( often need other substances to increase absorption) Loss of mineral in urine and feces
True or false 70% of absorption of water occurs in the small intestine. How does it occur?
false. 99% of absorption occurs in the small intestine via diffusion with an osmotic gradient
OsmolaRity: measure of [solute] /unit _______
simply, it is the ________of a solution
VOLUME (Osm/L)
concentration
Why is Osmolarity difficult to measure with consistency?
Δ volume w/ Δ temp/press, therefore more difficult to measure w/ consistency
- OsmolaLity: measure of [solute]/unit ______
- concentration of _____ dissolved in a solution
- True or false volume of solvent remains constant with / Δ temp/press, therefore reliable for measurement
- MASS (Osm/kg)
- particles
- True
Urine Osmolality: Normal 24-hr value in adults: _______ mOsm/kg
How will this number shift in a state of hypohydration vs. hyperhydration?
500-800 mOsm/kg
hypohydration: Increase
Hyperhydration: Decrease
Gastric Emptying: High CHO (low fat) meals empties in ___ hr
4 hours
High FAT meal empties in ____ hr
6 hours
Why is a high FAT meal slower to empty?
Harder to breakdown, more complex bonds Also abosobtion route
Which has a faster GE rate: food or fluid?
Why?
Fluid
Less time nand energy for mechanical breakdown
Gut-Microbiota-Brain Axis. Two systems that affect the body stress response during exercise:
1.
2.
- SAM (sympatho-adrenomedullary)
2. HPA (hypothalamus-pituitary axis)
Gut brain axis. Communication of stress response happens in which ways?
- Release of NE, EP, glucocorticoids
- Vagal nerve stimulation
- Gut hormones (GABA, neuropeptide Y, domapine)
Gut microflora communication with brain and muscles how? At which cellular level do the gut microflora talk with the muscles
a .via byproducts of fermentation (ShortChainFattyAcids, tryptophan)
b. mitochondria
True or false. Gut microflora may play a significant role in Control stress, anxiety, and depression.
true.
Is the gut micro flora active in Oxidative stress and inflammatory responses?
Yes
HOw is the gut microflura active in Energy metabolism?
microbiota-mitochondria crosstalk via SCFA’s
Research has demonstrated that gut bacteria can modulate the HPA axis through which two ways?
synthesis of hormones and neurotransmitters, namely, serotonin dopamine GABA Tryptophan precursor
True or false. “Beneficial” bacteria may also down regulate production of cortisol and noradrenaline. State why this is or isn’t beneficial
True. can help modulate stress response/ chronic stress
a ._________ (Bidirectional /unidirectional )communication exists between the gut microbiota and skeletal muscle.
b. if unidirectional which way ( gut -> muscles or muscles ->gut)
a .Bidirectional
Bacteria digest _________in the gut, and also degrade _______
oligo- and monosaccharides
bile acids
Byproducts of the ________ via microbiota digestion are released into the blood stream, and affect signal transduction at the ______in skeletal muscle
biles acids and saccharides
level of the mitochondria
Secondary Bile acids: Modulate ________in mitochondria AND
Stimulate __ ____ and oxidation
transcription factors
FA uptake
What does this describe? End products of fermentation of non-digestible dietary fibres by intestinal bacteria
Short chain FA
What are some Short Chain Fatty acids? Which is the most beneficial one? What can they do?
Acetate, prioprionate, butyrate
Buturate
1.Can modulate cellular inflammation and energy pathways
2. Can regulate skeletal muscle GLU and FA metabolism
True or false, resistance starches cannot Can be digested by bacteria in the gut and turned into SCFA
False. While they cannot be digested in the human body they can be digested by bacteria in the gut and turned into SCFA ( via fermentation)
Byturate production comes from a high fiber diet?
Yes
How does byturate carry out it’s physiological functions?
Increased Mitochondrial activity
G-protein coupled receptors
Histone acylation
Microbiome homeostasis
Probiotics: _______ and ______ strains demonstrate promising effects; sources include yogurt, kefir, supplements e.g. Bio-K
Bifidobacterium & Lactobacillus
True Or false? large dosages can be toxic
True
How does maintaining a ‘healthy gut’ benefit the physiological function and performance of an athlete?
better absorption and digestion
better immune system function
better functioning mitochondrial parameters
increases uptake and oxidation of FA
Fill in the blank. Healthy GI Function: +/- no effect (_) digestion/absorption (_) neuro-endocrine balance (_) immune function (_) psychological wellness (_) endurance performance (_) faster recovery
+ all
What type of athlete most commonly experiences exercised-induced GI distress?
Long repetitive, high impact sport
What percentage of athletes experience GI distress?
25-70
The following are symptoms of upper or lower GI distress: Reflux/Heartburn Belching Bloating Stomach pain/cramps Nausea Vomiting
Upper GI Distress
The following are sympotomes of upper or lower gi ditress? Intestinal cramps Side ache Flatulence Urge to defecate Diarrhoea/loose stool Intestinal bleeding
lower
What are two most common compensation strategies used by athletes to minimize symptoms?
Don’t eat before competition
Have a bowel movement
Causes of GI Distress:
- Changes in _____
- Splanchnic _____perfusion
- Absorption and gut ____
- Junctions in epithelial wall may______, depends on _______[condition]
- motility
- hypo
- permeability
- break down, depends on protective factor of gut
Changes in gastric occur at ~ ___% VO2max: These changes include an increase or decrease in:
__ pressure of LowerEsophagealSphincter
__ duration, frequency and amplitude of esophageal
peristalsis
___ rate Gastric Emptying
__ transit time in small intestine ( __ peristalsis)
__ transit time in the colon ( __ mucosal secretion
dilutes colonic contents)
60-70%+
_ ↓ _ pressure of LowerEsophagealSphincter
↓ duration, frequency and amplitude of esophageal
peristalsis
_↓__ rate Gastric Emptying
↑ transit time in small intestine ( ↓ peristalsis)
↓ transit time in the colon ( ↑ mucosal secretion
dilutes colonic contents)
is overall oro-caecal transit time affected by exercise?
For most athletes?
No +
True or false. Exercise shunts BF to muscles.
Shunting is proportional to ______
a .true. To muscles for O2 and substrate transport
and skin for thermoregulation
b. exercise intensity
Δ in intestinal permeability (due to exercise ) is normally short-term or longer-term
short term
Strategies to prevent splanchnic hypoperfusion
_____ exercise intensity (monitored via HR)
_______ ______intensity during a single session
Avoid use of _______(3-5x risk of GI issues)
Modify nutrition intake, train the gut
- Reduce
- Gradually increase
- NSAIDS
Nutritional strategies to prevent splanchnic hypoperfusion
Avoid ingesting food ___prior
When ingesting ________, avoid hyperosmolar fluids, use combination ________fluids/gels
Consume healthy _____ post-recovery (may help to improve postexercise splanchnic BF, attenuate inflammation)
2-3hr
CHO during exercise
GLU+FRUC
lipids
A chronic change in intestinal Permiability ( increase due to truama or NSAIDs use, etc) reults in which physiological outcomes?
Inflammation
Bacterial Translocation
True or false. Subtances like Citruline may help with Splanchic Hypoperfusion?
True. Via the NO pathway ( Vasodialation of Blood vessels) Glutamine and possibly arganine may help as well
Can you consume CHO during exercise without experiencing GI distress?
Yes, if its hypoosmolar
High [CHO] in a small, dense bolus might be tolerated
Tolerance in studies range from ___g CHO/hr to upwards of ___/min (___ g/hr), GLU+FRU (gel)
60 g/hr
1.4 g/min
84g/hr
Osmolality of blood serum: ______ mOsm
300
Which one of these are more likely to cause GI distress via delayed GE?
Full cream – 275 mOsm
Ice cream – 1150 mOsm
Grape juice – 11700 mOsm
Grape juice. Super hyperosmolar
__________beverages (i.e. _____ mOsm) empty the stomach quickly (e.g. sports drinks ___% mix of sugars/polymers)
Iso-osmolar/isotonic
~300 mOsm
6-8%
Hyperosmolar Beverages
Side effects??
- Gastric discomfort
- Vomiting (even at 8% [CHO]; sensitivity is individual)
- Osmotic diarrhea (if consumed in large amounts or just prior to competition)
True or false? Repeated ingestion of slightly increased volumes of food and drink during exercise can slightly increase GE rate.
True. it takes about 20s
Why must Gut training practiced during training must remain same during competition
Consumption of ‘unfamiliar’ fluids/food can double risk of GI symptoms
repetitive torso movement/twists, bouncing and after recent ingestion of fluid/food can lead to __________
ETAP (exercise-induced transient abdominal pain)
–> Aggravation of peritoneum and translocation of peritoneal fluid
