Water, Electrolytes, Acid Base Balance Flashcards
What does “balance” mean in terms of water and electrolytes?
What does it mean that they are interdependent?
equal amounts enter and leave the body. This is needed for homeostasis.
Electrolytes dissolve in water. So if someone is dehydrated then electrolytes are concentrated and vice versa. What happens to one affects the other
Is bodily fluids in humans evenly distributed?
How much water is in an average adult?
What portion is intracellular? what is extracellular?
no
40 liters of water
two thirds is intracellular
one third is extracellular
What percentage of an adult female is water? Male?
why?
52%
63%
men have more muscle generally, they need more water for muscle function. Women have more adipose tissue, and that does require as much water
What is the composition of extracellular fluid and intracellular fluiud?
high concentrations of sodium, calcium, chloride, and bicarbonate ions.
high concentrations of potassium, magnesium, phosphate, and sulphate
What are the two major factors that regulate the movement of water and electrolytes from one fluid compartment to another?
Hydrostatic pressure and osmotic pressure
When does water balance exist?
Why is this important?
When water intake equals water output
Required for homeostasis
How much of the brain is water?
How much of blood?
How much of bone?
75%
92%
22%
What is the average amount of water individuals gain each day?
What are their sources?
2500 milliliters
60% from drinking
30% from moist foods
10% as a byproduct of oxidative metabolism
How is water intake regulated?
when the body loses as little as 1% an increase of osmotic pressure stimulates the thirst center
hypothalamus causes the person to feel thirsty
Drinking and distention of the stomach by water trigger a negative feedback to stop the thirst center
water is absorbed through walls of the stomach and small intestines
osmotic pressure of extracellular fluid returns to normal
How does the body lose water?
60% in urine
6% in feces
6% in sweat (sensible perspiration)
Evaporation from skin and from lungs during breathing together is 28% (insensible perspiration)
What are the most important electrolytes and where do we get them?
What may happen with a severe electrolyte deficiency?
sodum, potassium, calcium, magnesium, chloride, sulphate, phosphate, bicarbonate, and hydrogen ions
We get from food, but some are in other beverages and water
Salt cravings
How do we lose electrolytes? What is the greatest output?
perspiration, poop
result of kidney function, and urine output
What electrolytes are the absolute most important ones?
positively charged ions like Na, K, and Ca
What are acids?
Bases?
why is Acid/Base balance important?
Electrolytes that ionize in water and release hydrogen ions
Substances that combine with hydrogen ions are bases
slight changes in H+ concentration can alter the rates of enzyme-controlled metabolic reactions, modify hormones, or shift the distribution of other ions
What are some sources of hydrogen ions resulting from the processes below?
Aerobic respiration of glucose
Anerobic respiration of glucose
incomplete oxidation of fatty acids
oxidation of sulfur-containing amino-acids
hydrolysis of phosphoproteins and nucleic acids
Carbonic acid Lactic acid Acidic ketone bodies Sulphuric Acid Phosphoric acid
