Lecture 5 Flashcards
What is Endogenous input for water? How much is this?
Chemical reactions in the body that have water as a biproduct
200-300 mL
What are insensible losses of water? How much is this?
Loss of water from breathing or sweating
350 + 400-900 mL
What are the factors that influences recommended water intake?
- Diet
- Insensible losses
- Environment
- Genetics
What is the recommended amount of fluid per energy expended?
approx 0.23 - 0.36 mL/kJ expended
How does the body compensate for fluid loss?
- Decreases urine output
- Increases fluid intake via thirst
What is thirst?
Conscious desire to drink water and is the primary regulator of fluid intake
How is the thirst response influenced by age?
- Blunted in older adults
- Commonly ignored in young children
What are the symptoms of mild dehydration?
- Headache
- Alert
- Restless
- Thirsty
What % of body weight is lost when mildly dehydrated?
2-5%
What are the symptoms of Moderate dehydration?
- Lethargic
- rapid pulse
- Decreased BP
- Dry mouth/eyes
- Shrunken frontanelle (part on a baby’s head)
- Skin retracts slowly
- Urine concentration increases
What % of body weight is lost when moderatley dehydrated?
6-10%
What are the symptoms of severe dehydration?
- Drowsy
- Limp
- Rapid feeble pulse
- No urine
- Death in child within 24 hours
What % of body weight is lost when severely dehydrated?
More than 10%
What is the most common cause of death to children in third world countries?
Severe dehydration
What is the treatment for mild dehydration?
- Drink water
- Increase fluid intake
- Eat
What is the treatment for moderate and severe dehydration?
- Medical approach/ high income countries = IV solution
- No medical access/ low income countries = ORS and zinc
What is an ORS?
An oral rehydration solution
- Rehydrates and replaces key electrolytes (Sodium, Potassium, Bicarb)
- Uses the co-transport of Na+ and glucose, rehydrates faster than drinking water
What are classed as carbohydrates?
- Starches
- Sugars
- Dietary Fibre
- Glycogen (not considered in diet)
What are the monosaccharides?
- Glucose
- Fructose
- Galactose
What does glucose serve as?
An essential energy source
TRUE/FALSE
Galactose commonly occurs naturally as a single sugar
FALSE
Galactose rarely occurs naturally as a single sugar
Which of the monosaccharides is the sweetest?
Fructose
What are the three disaccharides?
- Lactose (g+galactose)
- Sucrose (g +f)
- Maltose (g+g)
How is maltose produced?
During germination of seed and fermentation
How is sucrose produced?
Refined from sugar cane/beets
What are dietary fibres resistant to?
Digestion in the SI, usually are completely/partially fermented in the LI
What does dietary fibre promote?
- Laxation
- Decreasing blood cholesterol
- Modulation of blood glucose
What are non-starch polysaccharides broken down by?
Not broken down by SI enzymes, are broken down by LI microbiome
What are the intrinsic factors of NSP’s?
- Physically inaccessible e.g. hard shell covering
- Starch granules
What are the extrinsic factors of NSP’s?
- Chewing time (not enough)
- Transit time
