Pathophysiology Chapter 24

body fluids are secreted into

joints, cerebral ventricle, intestinal lumen

total body fluid

pertains to water within the body and the particles dissolved in it

intracellular fluid

(ICF) fluid within cells

Extracellular fluid/ ECF

interstitial compartment, vascular compartment, dense connective tissue and bone, transcellular fluid

hydrostatic pressure

outward push against walls

osmotic pressure

inward pulling forces

fluid intake

entry of fluid into the body by any route

healthy people ingest fluids

orally through drinking and eating(water contained in food)

cellular metabolism

small amount of water synthesized through this

functions of body fluid

surrounds and permeates cells, lubricant and solvent for metabolic chemical reactions, transports oxygen, nturients, chemical messengers and wastes to their destinations, important in regulating body temperature

abnormalities in body fluids

can occur in volume, concentration, electrolyte composition of body fluid, leads to clinical problems or death

fluid homeostasis

dynamic process results from fluid intake, absorption, distribution, and excretion

regulation body fluid volume

hypothalamus, RAAS, natriuretic peptides

water metabolism and hypothalamus

neuron stimulation in hypothalamus leads to sensation of thirst, ADH releasted from posterior pituitrary, increasing water absorption in kidney, decreasing output of water/hypertonic urine

renin-angiotensin-aldosterone system

neurohormonal regulatroy mechanism for body water and sodium increasing water volume and sodium reabsorption

renin

proteolytic enzyme made by kindey

renin converts

angiotensinogen to angiotensin I in liver, then to angiotension II in lung and kidney

natriuretic peptides

family of peptides that have reciprocal effects to RAAS, arterial natrietic peptide, brain natriuetic peptide, C type natriuretic peptide

disoders of water balance result from

imbalance of water intake and output OR imbalance of dium intake and output leading to dehydration or overhydration

dehydration can be due to

deficit of water(simple dehydration) or deficit of water and sodium

hyponatremic dehydration

hyposmolar dehydration, cell swells

normonatremic dehydration

isomolar dehydration, cell normal size

hypernatremic dehydration

hyperosmolar dehydration, cell shrinks

hypernatremic dehydration examples

food and water deprivation, excessive sweating, diuretic therary/osmotic diuresis

normonatremic dehydration examples

vomiting/diarrhea, replacement with low sodium liquids in deprivation

hyponantremic dehydration examples

diuretic theraoy, excessive sweating, salt wasting renal disease, adrenocortical insufficiency

edema

excess fluid in interstitial compaortment

possibilities for edema

increased capillary hydrostatic pressure

sodium/water retention

blockage of lymphatic drainage

decreased capillary osmotic pressure

electrolytes

ionized salts dissolved in water

most clinically important electrolytes

sodium, potassium, calcium, magnesium, chloride, bicarboante, phosphate

dynamic control

concentration of an electrolyte in plasma is different from its concentration in the cell

for body function

electrolyte concentration must be normal in plasma and in the cells

control of electrolyte levels is dynamic

if intake increased, excretion may also increase to normalize plasma levels, same with decreases

maintenance of electrolyte concentrations

electrolyte intake, absorption, distribution, and excretion work together to maintain dynamic control to keep electrolytes within normal limits

hyponatremia

low plasma sodium

hypernatremia

high plasma sodium

clincial conditions resulting in excess body sodium

cardiac failure, liver disease, renal disease/nephrotic syndrome, hyperaldosteronism, pregnancy

clinical conditions resulting in low body sodium

vomiting, diarrheaa, excessive sweating, hypoaldosternoism, diuretic therapy, osmotic duresis, burns, SIADH

clinical codition associated with hyponatremia

water excess greater than sodium excess, innapropriate ADH secretion, hyporthyroidism, heart failure, liver disease, sodium deficit greater than water deficit, hypoaldosternosm, sickle cell

clinical conditions associated with hypernatremia

excessive sodium intake, hyperaldosternoism, water defiicnecy greater than sodium defiicency, hyperventialation, dimished thrist

hypokalemia

low plasma potassium

hyperkalemia

high plasma potassium

causes of potassum depletion

alcoholism, low potassium diet, anorexia, gastro loses, increased urinary loses, primary aldosteronism, renal disease

causes of hypokalemia

alkalosis, increased plasma insulin, diuretic administration, decreased potassium intake, gastro loses, urinary loses

caueses of hyperkalemia

hemolysis, leukocytosis, acidosis, tissue hypoxia, isulin deficiency, high potassium intake, decreased potassium excretion