Flashcards in chapter 27 Deck (39):
1
fluid
-definition
-2 types
-water
-1. extracellular fluid
2. intracellular fluid
2
extracellular fluid
blood plasma, interstitial fluid, other
3
intracellular fluid
cytosol (within cells)
4
eletrolyte
-definition
-most important
inorganic compounds that dissociate in solution to form ions
-sodium
5
electrolyte: sodium
-most abundant where
-function
-in the CSF
-main contributor to osmolarity of blood
6
2 factors that must be controlled
1. fluid balance
2. electrolyte balance
7
fluid balance
-water gained=
-normal blood vol
-water lost
-~5 L
8
electrolyte balance
-electrolytes in =
-normal blood osmolarity
-electrolytes out
-300 mOsm/L
9
how do you gain water?
-lose?
-food, beverage and metabolism
-urine, feces, sweat and breathing
10
application: suppose you eat an extra large jumbo tub of movie popcorn with extra salt and butter
-blood osmolarity will
-blood vol will
-how does the body detect these changes?
-increase
-not change
-osmoreceptors in hypothalamus will sense an increase in blood osmolarity (sense of an increase in the concentration of Na+ of blood)
11
application: suppose you eat an extra large jumbo tub of movie popcorn with extra salt and butter
-how does the body respond to these changes?
-effect
-increasing secretion of antidiuretic hormone
-decrease secretion of aldosterone
-restore osmolarity of blood by increasing retention of H2O and decreasing reabsorption of sodium; kidneys produce small vol of concentrated urine
12
increasing secretion of antidiuretic hormone effects
1. increase thirst (consume liquids)
2. decrease water loss at kidneys
13
decreasing secretion of aldosterone effects
decreases Na+ reabsorption in kidney
14
application: suppose you drink a very large volume of water
-blood osmolarity will
-blood volume will
-how does the body detect these changes
-decrease
-increase
-osmoreceptors detect a decrease in the concentration of Na+ of the blood
15
application: suppose you drink a very large volume of water
-how does the body respond to these changes?
-secretion of ADH will decrease
-secretion of aldosterone will increase
-kidneys produce a large vol of dilute urine
16
decreasing secretion of ADH efects
-decreases water reabsorption in DCT and CD
-decreases thirst
17
increasing secretion of aldosterone effects
increases sodium reabsorption
18
application: suppose you consume a large vol of an isotonic solution
-blood osmolarity will
-blood vol will
-how does the body detect these changes
-not change
-increase
-baroreceptors will detect an increase in BP because of an increase in blood vol
19
application: suppose you consume a large vol of an isotonic solution
-how does the body respond to these changes
secretion of atrial natriuretic peptide will increase
20
increasing secretion of ANP causes
-effects
-ADH secretion to decrease
-aldosterone secretion to decrease
-kidneys will produce increased vol of urine with and increased Na+ content
21
application: suppose you are in a very severe car accident and are suffering from excessive blood loss
-blood osmolarity will
-blood vol will
-how does the body detect these changes
-not change
-decrease
-as blood vol decreases, BP declines
22
application: suppose you are in a very severe car accident and are suffering from excessive blood loss
-how does the body respond to these changes?
1. increase in ADH release
2. increase renin secretion
-both work to return blood vol and pressure to normal
23
increasing renin secretion =
increase in angiotensin II activation
24
angiotensin II activation
-3
-increases aldosterone release which increase Na+ retention in the kidneys because water follows salt and water will be retained
-causes vasocontriction = increased BP
-promotes release of ADH
25
pH
-definition
-formula
-pH of extracellular fluids
-concentration of H+ ions in a solution
- [H+] = 1 x 10 ^ -7 M --> pH = 7
- 7.35 - 7.45
26
2 conditions of pH
1. acidosis
2. alkalosis
-primarily effects CNS and cardiovascular functions
27
acidosis
-pH
-serious?
-below 7.35
-very serious problem
28
alkalosis
-pH
-serious?
-above 7.45
-serious but not as common
29
why is the maintenance of pH a problem?
-H+ gains=
-constantly producing H+ through
-formula
-H+ must be
-H+ loses
-metabolic activities
-Co2 + H2O H+ + HCO3-
-eliminated or "tied up" to maintain pH
30
3 mechanisms of acid-base balance
1. buffer system
2. respiratory system
3. urinary system
31
buffer system
-buffer
-3 major systems
-compound that stabilizes the pH of a solution by providing or removing H+ ions
-1. protein buffer system
2. carbonic acid-bicarbonate buffer system
3. phosphate buffer system
32
protein buffer system
-definition
-type of protein
-AA accepts or releases H+ ions
-hemoglobin
33
how does hemoglobin play a role in the protein buffer system?
by maintaining pH as pCo2 changes
34
carbonic acid-bicarbonate buffer system
-formula
-function
-what happens when equation shifts to the left
-Co2 + H2O (H2Co3) H+ + HCO3-
-can prevent changes in pH after addition of H+ ions
-Co2 is released in lungs
35
phosphate buffer system
-equation
-function
-H2Po4- H+ + HPo4 ^2-
-plays a supporting role in maintaining pH
36
respiratory system
-what do changes in respiratory rate do
-direct effect on
-equation
-stabilizes pH of ECF
-direct effect on carbonic acid/bicarbonate buffer system
-Co2 + H2O H+ + HCO3-
37
respiratory system
-increase in pCo2 =
-decrease in pCo2=
-decrease in pH = increase in respiratory rate = more Co2 lost at lungs = pCo2 and pH returns to normal
-increase in pH= decrease respiratory rate = less Co2 lost at lungs = pCo2 and pH returns to normal
38
urinary system
-definition
-occurs where
-principle of buffering system
-changing the rate of H+ and HCO3- secretion or reabsorption by the kidneys regulates the pH of the ECF
-along the PCT, DCT and CD
- Co2 + H2O (H2CO3) H+ _ HCO3-
39