fluid and electrolye imbalances Flashcards
what are the functions of water?
- major component in both intra & extracellular spaces
- medium for metabolic processes
- transportation - carries nutrients and removes waste
- facilitates movements of joints, lungs, and heart
fluid compartments
- approx. 60% of body composed of water.
- females (b/c they have more fat than man), the obese and elderly have less water.
- ICF (intercellular fluid - major)
- ECF (extracellular[outside of the cell] - intravascular, interstitial [b/w cells], CSF, trans cellular [around joints])
what are the 3 mechanisms to maintain fluid balance
- thirst mechanism
- ADH
- aldosterone
what is the thirst mechanism
it is in the hypothalamus, the osmoreceptors cells of which sense the internal environment, both fluid volume and concentration, and the promote the intake of fluid when needed
what is the ADH mechanisms
- controls the amount of fluid leaving the body.
- adh promotes reabsorption of water into the blood from the kidney tubules
- low ADH means dilute urine
- high ADH means concentrated urine
what is the aldosterone mechanism
- aldosterone is a hormone released from pituitary gland, made in hypothalamus.
- it determines the reabsorption of both sodium ions and water from the kidney tubules.
- this hormone converses fluid loss when there is a deficiency.
- stimulus for RAAS: low NA, or high K
water moves between blood vessels and compartments through cap membranes, and this movement is dependant on??
- hydrostatic pressure - push force out
2. osmotic pressure - pull force in
hypotonic solutions
contain less solute than plasma which will cause water to leave the solution and enter the area of higher concentration, this resulting in cells swelling or expanding.
why would there be an obstruction in the lymph vessels?
- tumors
- mastectomy
- node removal
lymphatic system is like the back door for drainage, if there is a block, what will occur?
edema
what is edema?
edema is a excess fluid in the interstitial compartments resulting in enlargement of tissues
to help shift water between compartments, we can use these which eventual water follows?
electrolytes
etiological factors of edema
- increase cap permeability - when in perm, more fluid moves into IS space
- obstruction in lymph vessel - obstruction to the back door drain system
- increase hydrostatic pressure - higher atrial pressure than venous pressure means more leaking from cap into IS than coming back than is being removed
- loss of plasma proteins - with fewer proteins in cap, it allows more fluid to leave cap and less fluid to return at venous end.
what are the effects of edema
- swelling
- pitting
- increase in body weight
- function impairment
- pain
dehydration
- 5 to 7 L fluid in body
- mild dehydration 2% loss of TF
- severe dehydration 8% loss of TF
- results in a loss of electrolytes, proteins, as well as a decreased blood volume
etiological factors of dehydration
vomiting diarrhea sweating insufficient intake of fluid diabetic ketone acidosis
keytones are the result of
fat breakdown
what happens when the body compensates for dehydration?
- cutaneous vasoconstriction (resulting in pale, cool skin)
what does the parathyroid hormone do?
- helps put calcium into blood.
- weak bones happen when you don’t eat enough calcium, and calcium is removed from the bones
what does vD promote?
vC into bones
function of sodium in the body
- nerve impulses
2. important in maintenance of extracellular fluid volume through osmotic pressure,
effects of dehydration
dry mouth decrease skin turgor low BP fatigue head ache confusion increase HR thirst concentrated urine
etiological factors of hyponatremia
- direct loss of sodium from body
- excess of water in the extracellular compartments
1. excessive sweating
2. diuretics
3. hormonal imbalances
4. early chronic renal failure
etiological factors of hypernatremia
- large ingestion of sodium
1. insufficient ADH - results in large volume of dilute urine (diabetes insipidus)
2. loss of thirst mechanism
3. watery diarrhea
4. prolonged periods of rapid respiration