Chapter 24 fluid, electrolyte, and pH balance Flashcards
what 8 systems help maintain fluid, e-, pH balance?
- urinary
- respiratory
- digestive
- integumentary
- endocrine
- nervous
- cardiovascular
- lymph
% fluid in ICF and ECF (ECF breakdown)
ICF 65% ECF 35% -25% interstitial -8% blood and lymph -2% other (eyes, joints)
what is the most abundant solute in fluids?
Electrolytes - Na+ in ECF and K+ in ICF
where are osmoreceptors found?
hypothalamus
how does the hypothalamus help regulate fluid balance?
stimulates the secretion of antidiuretic hormone from posterior pituitary
our conscious sense of thirst is generated in the…
Cerebral Cortex
does sympathetic of parasympathetic control salivation?
sympathetic
difference between short term and long term inhibition of thirst?
long term - balances osmolarity between compartments
short term - cooling or moistening of mouth (ice chips) to temporarily stop the sensation of thirst (30-45min)
what is the primary hormone that acts directly on water?
ADH
what are the 2 main hormones that act on salt?
aldosterone=retain salt
Atrial Naturetic Peptide=loose salt
what is the difference between Hypovolemia and Dehydration?
Hypovolemia is low water and solutes so osmolarity is maintained
Dehydration is low water levels with regular levels of solutes so osmolarity is high
how does cold weather effect fluid levels?
blood vessels constrict to hold heat in core -> baroreceptors sense high BP -> urine output is increased to lower BP
What is the difference between Hypovolemia and Hypotonic Hydration?
hypovolemic - high levels of solutes and water and remains isotonic
hypotonic hydration -too much water and regular levels of solutes
which 2 electrolytes are most important for cell excitability? ad which cavity is high in which?
Na+ high in ECF and K+ high in ICF
what are 3 addl hormones that act on Na+?
estrogen - retains Na+ to help retain water
progesterone - diuretic effect
Glucocorticoids - stress, dump sugar in blood, promote Na+ reabsorption
hat is the most dangerous electrolyte to have imbalance of?
K+
what percentage of K+ in primary filtrate is reabsorbed?
90%
how does Cl- effect CO2 levels?
Chloride shift - load and unload CO2 from RBC
what are the primary functions of Ca+ in the body?
bone strength
contraction
exocytosis
clotting
calcium will always bind to….
phosphorous
what do we want Ca+ pumped out of cell?
high phosphate in cell and don’t want Ca+ to bind with it and maintain -charge
Slight deviation from normal pH can….
shut down entire metabolic pathways AND alter the structure and function of macromolecules (DNA and Proteins)
do acids of bases release/give H+? which receive H+?
acids are donors - bases are receivers
increased CO2 leads to… (pH related)
increases acidity, decreases pH, eventually cerebral artery constriction
decreased CO2 leads to….(pH related)
increases alkalinity, increases pH,
what are 4 common acids produced by metabolism?
Lactic Acid
Phosphoric Acid
Fatty Acids/Ketones
Carbonic Acid
what are the bodies 2 physiological buffers?
urinary system - buffers large amounts over longer times and has greater effect on body pH
respiratory system - buffers small amounts in a few mins and not great effect on body pH
what organ is capable of neutralizing more acids or bases than either the respiratory or chemical buffers?
kidneys
how is pH level related to K+ levels?
Acids donate H+ -> diffuses into cell -> pushes out K+ = bad
Bases receive H+ ->pulls H+ out of cell -> draws K+ into cell = also bad
cells end up depolarized
what are the 2 categories of Acid/Base balance
Respiratory - acidosis - failure of alveoli - ie.Emphysema
Respiratory - alkalosis - form hyperventalation
Metabolic - acidosis - increased production of metabolic acids - ie. ketoacidosis
Metabolic alkalosis - rare - overuse of Tums or chronic loss of stomach acid
list the 5 fluid replacement therapies
Drinking water - eas
