Module 10 - Water & Electrolytes Flashcards
Where is water located in the cell? What is the distribution of water between these areas?
Intracellular (inside cell) (66%)
Extracellular (outside cell) (33%)
- intravascular (within blood vessels)
- intercellular/interstitial (between cells)
What is the formula for total body water?
ICF (intracellular water) + ECF (extracellular water)
Name and describe the 6 functions of water in the body
- solvent: dissolves solutes
- transports: transports water soluble substances
- lubricates: tears, fluid, saliva
- regulates body temperature: sweat
- chemical reactions: hydrolysis and condensation
- acid-base balance: prevents changes in pH
body water is distributed between ___ and ___ cellular spaces
intra and extra
amount of water in blood and tissue is determined by…
- blood pressure
- force generated by osmosis
high blood pressure at arterial side of capillaries forces water from…
the blood into the tissues
Low blood pressure at the venous side draws fluid…
back into the capillaries by osmosis
electrolytes help…
regulate body fluids by controlling fluid shifts in and out of cells (osmosis)
Name three common electrolytes
sodium
potassium
chloride
as cells move electrolytes in and out, water follows, enabled by…
osmotic pressure
What does osmotic pressure do?
moves water across membranes in presence of concentration gradient
What is lost through sweat from exercise?
water and electrolytes
True or false: there is a set guide for all people on how much water to drink.
False, while there is an AI value for water based on age and sex, recommended water intake can vary depending swear amount, illnesses etc.
True or false: drinking coffee reduces total body water.
false, recent studies have showed that coffee can be counted towards daily water intake
Water intake is usually from…
water, beverages, food and metabolic water (only about 250-600 ml depending on activity level)
Thirst is stimulated by…
- decrease of saliva excretion (dry mouth)
- amount of water in blood sensed by thirst centre in hypothalamus
What 4 ways is water loss in the body?
- urinating
- feces
- skin (evaporation, sweat)
- lungs (breathing)
What 5 factors can affect a persons water requirements?
- physical activity
- cold temperature (+urine)
- diabetes mellitus (polyuria)
- cystic fibrosis (high amount of NaCl in sweat)
- Diuretics (can cause excessive water loss)
What is Hyperhydration/Hyponatremia?
High water levels and low salt levels
What is Hypohydration/Hypernatremia?
low levels of water and high levels of salts
Signs of hypohydration “dehydration” include…
thirst, discomfort, flushed skin, cramps, headache, vomiting etc.
What factors can you use to indicate hydration level?
- thirst
- urine volume (+water=+urine)
- urine color (pale lemonade color 👍)
- change in body mass (+- 1% body mass change = well hydrated, more change then that could mean dehydration)
How does dehydration affect performance?
Decreases blood volume
Decreases blood flow
Decreases sweat rate
Increases core temperature
Increase heart rate
Increases perception of effort
Is there a known UL for water
No, but high amounts can result in hyponatremia (hyperhydration) - also known as acute water toxicity
True or false: overhydration is more dangerous then dehydration
True, it is called acute water toxicity
Why is acute water toxicity dangerous?
associated with hyponatremia (low salt levels) which causes kidneys to be overworked
Symptoms of Hyponatremia? - think of “boundless” documentary
nausea, vomiting, confusion, cramps, headache, seizures, coma, death
What makes hyponatramia so dangerous to treat? - boundless documentary
many of the symptoms are similar to hypernatremia (hypohydration), so if you misdiagnose it can be dangerous. (diagnose with hypernatremia instead then you will be giving more water to someone possibly suffering with over hydration)
What are minerals?
inorganic elements needed in relatively small amounts
Similarities and differences between vitamins and minerals
Similarities: do not provide kcal, but work with nutrients that enable body to get energy
Differences: Vitamins can be destroyed by heat, O2 or acid. Minerals can not be destroyed.
Major vs Trace Minerals
Major Minerals: needed in larger quantities, >100mg per day
Trace Minerals: needed in smaller quantities, <100mg
What are the main functions of minerals?
- part of enzymes
- work with immune system
- structural growth
- help chemical reactions take place in cells
- help muscles contract including heart
Cofactor vs Coenzyme
Cofactor: organic or inorganic, do not bind to enzyme, they are helper molecules
Coenzyme: organic, bind loosely to active site of enzyme
How do minerals work as cofactors? Describe the process
- Mineral cofactor combines
with the incomplete enzyme to
form active enzyme - The active enzyme binds to the
molecule and accelerates their
transformation into the final
products - Final products are released,
while enzyme remains
unchanged
What is a more reliable source of minerals: plant or animal foods?
Animal foods, they have higher concentration of minerals, also plant foods contain phytic and oxalic acid that interfere with mineral absorption
What do all electrolytes do?
regulate body fluids by controlling fluid going in and out of cells (osmosis)
What are the 3 major electrolytes
Sodium
Chloride
Potassium
What is the main extracellular cation, extracellular anion and intracellular cation?
Main Extracellular Cation: Sodium (+)
Main Extracellular Anion: Chloride (-)
Main Intracellular Cation: Potassium (+)
Sodium Toxicity is also known as ___. Symptoms?
Hypernatremia/Hypohydration. Lethargy, confusion, nausea, thirst,
What is a major issue that develops from Hypernatremia (too much sodium)?
Hypertension (increased retention of fluids due to high blood sodium - in sodium sensitive people, sodium excretion is slow causing high blood pressure
Sodium deficiency is known as ___? Symptoms?
Hyponatremia/Hyperhydration. Nausea, muscle cramps, headache, choma, death.
Source of Chloride
Salt and vegetables
The roles of potassium, the main intracellular cation, in the body
lowers high BP, fluid and electrolyte balance, nerve transmission
Processing of foods increases (electrolyte) and decreases (electrolyte)
increases proportion of sodium
decreases proportion of potassium
Potassium deficiency is known as __. Symptoms?
Hypokalemia. Muscle weakness, fatigue, heart complications.
Hypokalemia (potassium deficiency) is usually caused by…
high losses in body - diarrhea, vomitting, diuretics
Hyperkalemia (potassium toxicity) is usually caused by…
prescription drugs, dehydration, impaired kidneys
The role of sodium and potassium in nerve conduction (use a pinprick as an example)
Pinprick stimulates nerve beneath skin which increases permeability and allows sodium to enter nerve cell, initiation a nerve impulse
