Water (C) Flashcards
How many days can the body live without water?
3-5 days
What percent of the body is water?
50-60% (higher in men, 75% in newborns)
What percent of body fluid is made up by ICF?
65%
What percent of body fluid is made up by ECF (interstitial and intravascular)?
35%
What are the functions of water?
Major component of blood plasma, solvent, hydrolyzes nutrients, lubricates joints, cools the body, and provides minerals
What is the equivalent of one liter?
33.8ozs / 4.2 cups
Which body process produces water?
Energy metabolism
What are electrolytes measured in?
Milliequivalents (mEq/L)
What is the difference between sensible and insensible water loss?
Sensible: urine; insensible: sweat, feces, respiration
How much water must be excreted each day to remove waste products?
500mL
How does water move through the cell walls?
Osmosis (from the side with the lesser solute to the side with the greater solute)
What minerals are solutes to water?
Sodium, chloride, and potassium
Which mineral is the primary constituent of extracellular fluid?
Sodium
Which mineral is the primary constituent of intracellular fluid?
Potassium
What happens when the electrolyte concentration of ECF increases?
ICF moves to ECF, cells become dehydrated, and thirst occurs
What is vascular osmotic pressure?
A high concentration of electrolytes in the blood and low blood pressure
What happens when there is vascular osmotic pressure?
The hypothalamus tells the kidneys to secrete anti-diuretic hormone, reabsorbing and not excreting water
Which hormone is secreted by the adrenal glands that tells the kidneys to reabsorb sodium?
Aldosterone
What happens when extracellular sodium is decreased?
Water enters the cells; edema. Adrenal glands secrete aldosterone
What is the water requirement per calorie consumed?
1 mL per calorie
What is the water requirement for an 1800 calorie diet?
7.5 glasses
What is the water AI?
3L/ 13 cups for men; 2.2L/ 9 cups for women
Which conditions can increase water requirement?
Hyperthyroidism and type two diabetes
What are the symptoms of dehydration?
Low blood pressure, thirst, dry skin, fever, and confusion
What happens when 10% of body water is lost?
Blood volume, nutrient absorption, and kidney function decrease
What happens when 20% of body water is lost?
Circulatory failure and death
What percent of body weight lost is considered mild, moderate, or severe dehydration?
3-5% mild, 6-9% moderate, 10-15% severe
What are the symptoms of heat fatigue?
Thirst, weakness, and fatigue
What are the symptoms of heat cramp?
Thirst and leg cramps from depleted sodium and potassium
What are the symptoms of heat exhaustion?
Thirst, dizziness, nausea, headache, sweating
What are the symptoms of heat stroke?
Fever and potential brain/kidney damage
What is positive water balance?
Excess fluid accumulation
What causes positive water balance (and subsequent edema)?
Hypothyroidism, CHF, hypoproteinemia; some infections, cancers, and renal diseases
What does water intoxication lead to?
Hyponatremia, which is life threatening
Diet affects the pH of what?
Urine
What system regulates hydrogen ions and therefore acid-base balance?
Buffer systems
What is the ratio of bases to acid in the buffer systems?
20 bases: 1 acid (weak bases, strong acid)
What are the chief acids and bases in the body’s buffer systems?
Carbonic acid and sodium bicarbonate
How are carbonic acid and sodium bicarbonate secreted?
The lungs and kidneys respectively
What is the pH range for urine?
4.5-8, average 6
What are the causes of acidosis?
Renal failure, diabetes, starvation, and diarrhea
What are the causes of alkalosis?
Loss of hydrochloric acid (ie vomiting) or the ingestion of excess alkali (ie through antacid tablets)
