Osmoregulation Test Question Flashcards
Extracellular Fluid (ECF)
Interstitial fluid, plasma, other body fluids
Intracellular Fluid (ICF)
cytoplasm
Fluid Balance
an aspect of the homeostasis of organisms in which the amount of water in ICF and ECF solute concentration effects the movement of ions and water
Electrolyte Balance
ions from dissociation of inorganic compounds; affected by: kidney disease, Hormonal or endocrine disorders, loss of body fluids, lack of vitamins (reason too much sodium or calcium are very important-Aldosterone is a major hormone of ion balance)
pH balance
the amount of hydrogen ions input or output; respiratory can control by decreasing carbon dioxide and kidney get rid of hydrogen ions via collecting duct)
obligatory water gain and loss
gradients, surface to volume (smaller things lose heat), Permeability (aquaporin, protein water channels); feeding, metabolism, and excretion; respiration
regulation
homeostatic mechanisms respond to ECF (changes effect of entire body), ICF is localized and contained within cell membranes
Receptors
do NOT detect fluid amounts or ion concentrations,;can detect plasma volume and osmotic concentration; active solute per liter)
Cells
can NOT move water; water movement occurs passively, cells can move salts and water will “follow” salt
grams of metabolic water per gram of food
Fats> carbs> proteins
kilojoules expended per gram of food
fats> carbs> proteins
grams of metabolic water per kilojoule expended
Carbs> fats> proteins
secreted by magnocellular neurons of the hypothalamus
ADH
ADH
respond to osmotic concentration, stretch receptors, higher osmotic concentration, reduce water loss, stimulate thirst
From the suprarenal cortex
Aldosterone
Aldosterone
DCT and collecting duct, conserve sodium and potassium leaves tubule at higher rate, water retention or loss, increase sensitivity of salt, respond to rising potassium or falling salt
How is renin related to aldosterone?*
Renin increases production of aldosterone
secreted by cardiac muscle when stretched
natriuretic peptides
natriuretic peptides
opposes angiotensin II, promote loss of sodium and water at the kidney, inhibit renin release, secretion of Ash and aldosterone, suppress thirst, stimulate peripheral vasodilation
Atrial and Brain Natriuretic Peptides
right atrium and ventricles respectively
what prevents angiotensin and norepinephrine from elevating blood pressure?
Natriuretic Peptides
What is the net result of Natriuretic Peptides
reduction of blood volume and pressure, and hence the stretching of cardiac muscle
When afferent arterioles dilate and efferent arterioles contract what happens to GP and GFR
increased glomerular pressure and increased glomerular filtration rate
*Short, wide afferent arteriole=
low resistance input pathway
*Efferent arteriole plus vasa recta=
high resistance outflow pathway
Decreased ADH…
loss of thirst, increased water loss in urine
After drinking water (no electrolytes)…
ECF becomes larger and more dilute which shifts to ICF compartment, distributing effect
What can impact pH balance and kidney
increased/decreased Na+ concentration in ECF, ECF volume increased/decreased by fluid or fluid salt gain
