Ch 26 fluid, electrolytes: Exam 4

water account for what amt of body weight

1/3

which age is more hydrated

younger

gender and hydration

men have more muscle, so more water

fat’s water content

20%

skeletal muscle’s water content

75%

intracellular fluid

fluid found within cells (2/3 of water in body)

extracellular fluid

fluid outside cells (1/3 of water in body)

interstitial fluid

fluid between cells

electrolytes

things that separate into ions in water (conduct electricity)

nonelectrolytes

substances that don’t separate into ions in water

intracellular vs extracellular fluid

intracellular is higher in K+; extracellular is higher in Na+

intracellular and interstitial fluids are higher in

protein

how much water should be taken in & eliminated in a day

2500mL

thirst mechanism

dry mouth and excitation of thirst centers

how much water is lost through urine every day

500mL

triggers of ADH

low ECF concentration, low BP, low blood volume

disorders of water balance (3)

dehydration, hypotonic hydration, edema

dehydration

body is in negative fluid balance

dehydration causes

hemorrhage, burns, vomiting, diarrhea, diabetes

dehydration symptoms

dry mouth, thirst, dry flushed skin, oliguria

hypotonic hydration

cellular overhydration due to drinking excess water

hyponaturemia

salt become dilute even though there ie enough in body

hypotonic hydration symptoms

nausea, vomiting, cramping, cerebral edema

hypotonic hydration treatments

Mannitol and hypertonic saline

edema

accumulation of fluid in interstitial space (tissue swelling)

edema cause

increase in capillary blood pressure

salts

maintains proper neuron and muscle cell function

sodium

regulates ECF

sodium regulation (3)

Aldosterone, Atrial Natriuretic peptide, estrogen

aldosterone

increases sodium reabsorption in tubule and collecting duct

what causes release of aldosterone

increase in potassium or presence of Angiotensin II causes adrenal cortex to release

atrial natriuretic peptide (ANP)

inhibits release of renin, ADH, aldosterone (causes vasodilation)

estrogen

increases salt reabsorption

hyperkalemia

increase in potassium (K+) in ECF

hypokalemia

decrease in potassium (K+) in ECF

what organ is sensitive to K+ level changes

heart

calcium function

neuromuscular function

hypocalcemia

increases excitability and causes tetany

hypercalcemia

inhibits neurons and muscle cells; causes cardiac arrythmia

parathyroid hormone (PTH)

released when blood levels of calcium are low

PTH increases (3)

bone breakdown, calcium absorption

regulating pH (3)

chemical buffers, brain stem respiratory centers, renal mechanisms

phosphate buffer system function

important in urine and intracellular fluid where phosphate levels are higher

protein buffer system

regulates pH by releasing hydrogen

respiratory acidosis

impaired gas exchange

respiratory alkalosis

hyperventilation causes too much carbon dioxide to be removed

metabolic acidosis

low pH and bicarbonate ions

metabolic alkalosis

high pH (excessive vomiting)

acidosis effects

coma or death

alkalosis effects

nervousness, convulsions, respiratory arrest