Water & Electrolytes

most basic of nutrients

water

solvent for all chemical reactions

water

how is water considered a transport?

blood and lymph

how does water perform thermoregulation?

increased temperature causing sweat

how is water considered a lubricant?

synovial fluid; all moving body parts

what makes the largest portion of body weight?

water

what is the percentage of water to total body weight in a healthy adult?

45-75%

what is the average percentage total body weight of water in men?

60%

what is the average percentage total body weight of water in women?

50%

if a person has more muscle and less fat, what does that mean for water?

more body water

what is the average percentage total body weight of water in infants?

70-75%

why do older adults have less body water?

more adipose tissue

what is the minimum daily intake of water?

1500 mL/day

How much liquid should a woman drink a day?

2.7 L (2 L from fluid)

How much liquid should a man drink a day?

3.7 L (3 L from fluid)

what percentage of water comes from food?

19%

how many oz of water should come from food for women?

74 oz (9.25 cups)

how many oz of water should come from food for men?

101 oz (12.6 cups)

intake should ____ output

approximate

how much output is considered reasonable?

1000 mL through sensible loss

what part of urine is toxic and needs to be excreted

urea

what things can increase the daily output?

respirations
skin
fecal

how many mL of metabolic waste should be lost during obligatory loss?

500 mL urine daily

what can cause more output?

medications (diuretics)
caffeine (when used as a diuretic)

infants lose __% of their body weight in the first 10 days

10

why are infants at risk for dehydration?

large amount of water as their total body weight

why are older adults at risk for dehydration?

decreased thirst and less fluid intake

when are symptoms of dehydration shown?

as little as 0.5% of total body water

what is an indicator of need for hydration?

thirst

body water outside the cell

extracellular

what percentage of body weight and body water is extracellular?

20%
34%

¼ blood plasma

intravascular

surrounds cells and bathes tissues

intersititial

has water to help with fighting infection; giving fluid to cells to fight infection

lymphatic

GI tract, CSF, ocular, joint, urine in bladder

transcellular

body water inside cell

intracellular

what fraction of body water is intracellular?

2/3

what percentage of total body weight is intracellular?

35-45%

what is the largest amount of intracellular fluid composed of?

electrolytes

what electrolytes are in extracellular fluid?

sodium (cation) and chloride (anion)

what electrolytes are in intracellular fluid?

potassium (cation) and phosphate (anion)

large proteins that stay in the blood vessels

plasma proteins

where are plasma proteins synthesized?

liver

what do plasma proteins do?

pull water into vessels if needed
if not enough fluid leaks from capillaries and edema occurs

what is normal albumin level?

3.5-5 g/dl

this hormone is made in the hypothalamus and stored in the posterior pituitary and tells kidneys to reabsorb water

ADH (vasopressin)

aldosterone released from adrenal cortex and tells the kidneys to reabsorb sodium, water is reabsorbed by default

RAAS

what factors can affect hormones and water reabsorption?

kidney/liver issues, chronic alcohol use, TBI