chapter 27

Question 1

fluid

• definition
• 2 types

Answer 1

• water
• 1. extracellular fluid
     
     2. intracellular fluid

Question 2

extracellular fluid

Answer 2

blood plasma, interstitial fluid, other

Question 3

intracellular fluid

Answer 3

cytosol (within cells)

Question 4

eletrolyte

• definition
• most important

Answer 4

inorganic compounds that dissociate in solution to form ions

-sodium

Question 5

electrolyte: sodium
- most abundant where
- function

Answer 5

• in the CSF

- main contributor to osmolarity of blood

Question 6

2 factors that must be controlled

Answer 6

1. fluid balance

2. electrolyte balance

Question 7

fluid balance

• water gained=
• normal blood vol

Answer 7

• water lost

- ~5 L

Question 8

electrolyte balance

• electrolytes in =
• normal blood osmolarity

Answer 8

• electrolytes out

- 300 mOsm/L

Question 9

how do you gain water?

-lose?

Answer 9

• food, beverage and metabolism

- urine, feces, sweat and breathing

Question 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?

Answer 10

• increase
• not change
• osmoreceptors in hypothalamus will sense an increase in blood osmolarity (sense of an increase in the concentration of Na+ of blood)

Question 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

Answer 11

• 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

Question 12

increasing secretion of antidiuretic hormone effects

Answer 12

1. increase thirst (consume liquids)

2. decrease water loss at kidneys

Question 13

decreasing secretion of aldosterone effects

Answer 13

decreases Na+ reabsorption in kidney

Question 14

application: suppose you drink a very large volume of water
- blood osmolarity will
- blood volume will
- how does the body detect these changes

Answer 14

• decrease
• increase
• osmoreceptors detect a decrease in the concentration of Na+ of the blood

Question 15

application: suppose you drink a very large volume of water

- how does the body respond to these changes?

Answer 15

• secretion of ADH will decrease
• secretion of aldosterone will increase
• kidneys produce a large vol of dilute urine

Question 16

decreasing secretion of ADH efects

Answer 16

• decreases water reabsorption in DCT and CD

- decreases thirst

Question 17

increasing secretion of aldosterone effects

Answer 17

increases sodium reabsorption

Question 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

Answer 18

• not change
• increase
• baroreceptors will detect an increase in BP because of an increase in blood vol

Question 19

application: suppose you consume a large vol of an isotonic solution
- how does the body respond to these changes

Answer 19

secretion of atrial natriuretic peptide will increase

Question 20

increasing secretion of ANP causes

-effects

Answer 20

• ADH secretion to decrease
• aldosterone secretion to decrease
• kidneys will produce increased vol of urine with and increased Na+ content

Question 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

Answer 21

• not change
• decrease
• as blood vol decreases, BP declines

Question 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?

Answer 22

1. increase in ADH release
2. increase renin secretion
   - both work to return blood vol and pressure to normal

Question 23

increasing renin secretion =

Answer 23

increase in angiotensin II activation

Question 24

angiotensin II activation

-3

Answer 24

• 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

Question 25

pH - definition - formula - pH of extracellular fluids

Answer 25

- concentration of H+ ions in a solution - [H+] = 1 x 10 ^ -7 M --> pH = 7 - 7.35 - 7.45

Question 26

2 conditions of pH

Answer 26

1. acidosis 2. alkalosis - primarily effects CNS and cardiovascular functions

Question 27

acidosis - pH - serious?

Answer 27

- below 7.35 | - very serious problem

Question 28

alkalosis - pH - serious?

Answer 28

- above 7.45 | - serious but not as common

Question 29

why is the maintenance of pH a problem? - H+ gains= - constantly producing H+ through - formula - H+ must be

Answer 29

- H+ loses - metabolic activities - Co2 + H2O H+ + HCO3- - eliminated or "tied up" to maintain pH

Question 30

3 mechanisms of acid-base balance

Answer 30

1. buffer system 2. respiratory system 3. urinary system

Question 31

buffer system - buffer - 3 major systems

Answer 31

- 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

Question 32

protein buffer system - definition - type of protein

Answer 32

- AA accepts or releases H+ ions | - hemoglobin

Question 33

how does hemoglobin play a role in the protein buffer system?

Answer 33

by maintaining pH as pCo2 changes

Question 34

carbonic acid-bicarbonate buffer system - formula - function - what happens when equation shifts to the left

Answer 34

- Co2 + H2O (H2Co3) H+ + HCO3- - can prevent changes in pH after addition of H+ ions - Co2 is released in lungs

Question 35

phosphate buffer system - equation - function

Answer 35

- H2Po4- H+ + HPo4 ^2- | - plays a supporting role in maintaining pH

Question 36

respiratory system - what do changes in respiratory rate do - direct effect on - equation

Answer 36

- stabilizes pH of ECF - direct effect on carbonic acid/bicarbonate buffer system - Co2 + H2O H+ + HCO3-

Question 37

respiratory system - increase in pCo2 = - decrease in pCo2=

Answer 37

- 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

Question 38

urinary system - definition - occurs where - principle of buffering system

Answer 38

- 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-

Question 39

urinary system - where does the Co2 come from - principle of buffering system relies on - decrease pH of ECF - increase pH of ECF

Answer 39

- from tubular fluid, blood and tubular cells - relies on carbonic anhydrase in tubular cells - H+ is secreted into tubular fluid and HCO3- is released into blood = increase in pH of ECF in blood - HCO3- is secreted into tubular fluid and rate of H+ secretion declines = decrease in pH of ECF