Module 10- Fluid, Electrolyte, and Acid-Base Homeostasis Flashcards
what percentage of the body is made of fluid?
55-60%
which is more prevalent, Intracellular fluid or extracellular fluid?
Intracellular fluid is 2/3rds of the body and Extra cellular fluid is 1/3rd
What is extracellular fluid made up of?
80% Interstitial fluid and 20% blood plasma.
what are the two barriers that seperate intracellular fluid, interstitial fluid and blood plasma?
the plasma membrane and blood vessel walls
when is the body “Fluid Balanced?
When the required amount of water and solutes are present and proportioned in body compartments.
What is a major determinant of fluid balance?
Solute concentration
Explain the amounts of water gain and where they come from?
Most come from Ingested liquid and moist foods - 2300ml/day - GI Tract
Some from Aerobic cellular respiration - 200ml/day - Metabolic water.
Explain how water is lost from the body and the amounts
Gi tract- 100ml
Skin- 600ml
Lungs - 300ml
Kidneys - 1500ml
what governs the urge to drink?
the thirst center in the hypothalmas
what stimulates the thirst center?
low blood bolume = llow BP = renin release = formation of angiotensis 2 = stimulation of thirst centers
Neurons in the mouth detect dryness from saliva
What regulates water loss?
NaCl loss is the main factor determany body fluid volume
Increase in vlood volume stretches atria of heart releasing ANP, ANP promotes natriuresis ( loss of sodium in urine)
what does increase in blood volume do to renin and how does that effect water loss in the body?
decreases renin production which decreases angiotensis 2 which decreases aldosterone which decreases the reabsoption of Na and Cl.
how does ADH effect water loss in the body
An increase in osmotic pressure (decrease in water concentration of fluids) stimulates ADH which promotes the insertion of water channels and increases water permiability,
what are the 4 general functions of electrolytes?
1-Control osmosis of water between fluid compartments
2-Help maintain the acid-base balance
3-Carry electrical currents for action potentials
4-serve as cofactors needed for activity of enzymes
What is the most abundant extracellular Ion?
Sodium Na
what controls the level of sodium in the blood?
aldosterone anp and ADH
which electrolyte accounts for almost half the osmotic pressure of extracellular fluid?
Sodium Na
Where are Chloride ions most prevelent?
Extracellular fluid
How is Cl regulated?
Clhloride follows sodium so it is indirectly regulated by aldosterone.
Where is potassium most abundant?
Intracellular fluid
What does potassium play a key role in?
Membrane potentioal and repolarization, pH regulation because when potassium moves it is exchanged for H.
What acts to regulate potassium K?
when there is excessive potassium K, more aldosterone is in the blood, which stimulates the collecting ducts to secrete more Potassium, and excess Potassium is lost in urine.
Which is the most abundant ion in the body?
Calcium, 98% in skeleton and teeth
where is calcium found extra or inter cellular?
extracellular
