BODY FLUID + ELECTROLYTE BALANCE 1 Flashcards
why do men have more water than women
men have more water bc more muscle mass + women carry more fat
order the following tissues From most to least hydrated: skeletal muscle > bone > adipose
Skeletal muscle > bone > adipose
what are the two compartments of total body fluid
Intracellular fluid (ICF)
Extracellular fluid (ECF)
what makes up intracellular fluid (ICF)
2/3rd water volume; 40% of body weight
what makes up ECF
Consists of plasma and interstitial fluid (IF)
- 1/3rd water volume
whats interstitial fluid
fluid around cells; 80% of ECF
whats plasma
20% of ECF
what are electrolytes
Dissociate into ions in solution; can conduct electricity
do electrolytes have Greater ability to change osmolarity than nonelectrolytes
yes
what does increased osmolarity indicate
increased solutes
are electrolytes polar
yes
what are examples of electrolytes
inorganic salts (NaCl), acids and bases, some proteins
what are nonelectrolytes
Do not dissociate in solution; cannot conduct electricity
are non electrolytes polar or nonpolar
nonpolar
what are somme examples of nonelectrolytes
glucose, lipids, creatine, urea
what are the primary cation and anion in ECF
Na+ is the primary cation
Cl- is the primary anion
what are the primary cation and anion in ICF
K+ is the primary cation
Hydrogen phosphate (HPO42-)
is the primary anion
what does ICF contain in addition to the K+ and hydrogen phosphate?
many proteins
what are some examples of water losses
insensible water loss, sweat, fecal losses, urine
what are some examples of water intake
fluid intake, water from food, metabolic water
what must be maintained for water balance regulation
Must maintain ECF osmolality concentration
what happens when there’s an increase in plasma osmoality
→ Triggers thirst → drink fluids
→ Release of anti-diuretic hormone (ADH) → kidneys reabsorb water
what happens when there’s a decrease in plasma osmolality
→ Inhibits thirst
→ Inhibits ADH → large outputs of dilute urine
what happens to cells in hypo-osmolality
swollen and ruptured
what happens to cells in hyper-osmolality
dried out and shrunken
what happens to cells in iso-osmolality
happy
when we’re deprived of water, our plasma osmolarity goes up, which stimulates our osmoreceptors in the anterior hypothalamus. what does this result in
increase in thrist
and ADH secretion from posterior pituairty
what happens after ADH is secreted
increase in H2O permeability in distantl tubule and collecting duct, which results in ann increase in water reabsoprtionm and increase in urine osmolarity and decrease in urine volumme
when we have too much water, our plasma osmolarity goes down, which inhibits our osmoreceptors in the anterior hypothalamus. what does this result in
decrease in thrist and decrease in ADH which does the opposite of what was said before
what is thirst regulated by
hypothalamic thirst center
what is the hypothalamic thrist center activated by
osmmoreceptors, dry mouth and decreased blood volume
what do osmoreceptors detect and how
detect ECF osmolality
Gain or loss of water causes plasma membrane stretch
what does dry out do to osmotic pressure
Increased osmotic pressure leads to less saliva production
what is decreased blood volume or pressure detected by
baroreceptors
when is the thirst center inhibited
prematurely; before fully hydrated
whats insensible water loss
unavoidable water loss in skin and lungs
whats sensible water loss
(urine)
Minimum urine output: 500ml/day
Necessary to flush end products of metabolism
whats urine output beyond necessity determined by
fluid intake, diet, and other water loss
