Water Balance Flashcards
Substances that dissolve readily in water (ions or polar molecules)
Hydrophilic
Na+, Ca2+, Cl-, and HCO3- have a higher concentration inside/outside the cell?
Outside
Extracellular
A major change in solute concentration affects what?
Water distribution
What is the function of Mg2+ in the body?
Enzyme activation
Neural transmission
Osmosis
Movement of water through a semipermeable membrane
Membrane is selectively permeable to water and ions
ADH relapse has what two important effects?
Stimulates water conservation at the kidneys,reducing urinary water loss and concentrating the urine
Stimulate thirst center
What are the common causes of extracellular edema?
Abnormal leakage of fluid from the plasma to the interstitial spaces
Failure of the lymphatic vessels to return fluid from the tissues back into the blood (lymphedema)
Increased capillary pressure, decreased plasma protein, increased capillary permeability, blockage of lymph return
What are the common causes of intracellular edema?
Hyponatermia
Depression of metabolic systems of the cells
Reduced nutrition of cells
Inflammation
Methods of water intake
Ingested (drinking) liquid
Ingested food
Metabolic water, by-product of respiration
What is the function of K+ in the body?
Regulate water and electrolyte content of ICF
Neve impulse
Acid-base balance
When is an animal in fluid balance?
When the water gained each day is equal to the amount lost
Requires regulation of body water content and distribution
What three conditions leads to increased release of aldosterone ?
Fall in plasma volume / decrease blood pressure
Increased ECF osmolarity-> Na+ is not reabsorbed
Increased ECF K+ -> stimulate K=excretion
ANP release is stimulated by?
Abnormal stretching of atrial walls caused by high BP
How does ANP reduce blood volume and BP?
Increase water loss at kidney
Reduce thirst
Block release of ADH
Peripheral vasodilation
About 80% of ECF is ____________ and 20% is in _______________
Interstitial
Plasma
Hormone-mediated responses to water balance usually affect what?
Dietary absorption and urinary excretion
One-third of body fluid is _____________ fluid
Extracellular
What is the function of Na+ in the body?
Fluid volume of ECF Increase plasma membrane permeability Body water distribution Acid-base balance Nerve transmission
The higher the aldosterone concentration the more efficiently the kidneys will (reabsorb or secrete)? Sodium
Reabsorb
Conservation of sodium ions stimulates water retention
What is the function of Cl- in the body?
HCl in the stomach
Neve impulses
Physiological adjustments are regulated by ________
Hormones
About 1% of ECF is found is spaces such as lymphatic vessels, CSF, synovial joints, humors of the eye, ect. What is this water called?
Trancellular water
What functions of the body require CA2+
Bone and teeth building Blood coagulation Muscle contraction Neural transmission Enzyme activation Messenger molecule
A fluid shift occurs due to changes in _______ of the ECF
Osmolality
What are the functions of electrolytes in the body?
Normal cell metabolism and body structure (eg Ca2+ in bone)
Facilitate osmotic movement of water
Maintain hydrogen ion concentration
Production and maintenance of membrane potential and action potential
Two-thirds of body fluid is __________ fluid
Intracellular
Transient binding of water molecules
Hydrogen bond
Bound to others “flickering cluster”
_______ is the presence of excess fluid in the tissues (mainly ECC)
Edema
What three hormones normally regulate fluid loss?
Antidiuretic hormone (ADH) Aldosterone Atrial natriureteic peptide (ANP)
What is transcellular fluid? Does it have a major role in fluid balance in the body?
Fluid within a body compartment (eg ocular fluid, CSF)
No affect on fluid balance of body
Where is water lost?
Kidney
Skin (sweat)
Lungs - exhaled water vapor
GI tract- feces
Osmoreceptors in the hypothalamus stimulates ADH release due to (increase/decrease)? In osmolarity
Increase
The greater the osmolarity, the more ADH released
What does it mean for diffusion to be balanced?
Amount moving into a cell is equal to the amount moving out.
Net movement of water is zero and cell volume remains constant
K+, Mg2+, Phosphate, and proteins have a higher concentration inside/outside the cell?
Inside
Intracellular
Molecules with no polar bonds, insoluble in water. (C-H bonds)
Hydrophobic molecules
What is a solution?
A solute dissolved in a solvent
Asymmetrically arranged electrons on a water molecule makes it ________
Polar
Slightly negative end, and slightly positive end
