Fluid, Electrolyte and Acid Base Balance (chapter 26)

Question 1

66 % of total body water found here

Answer 1

Intracellular fluid (ICF)

Question 2

33 % of remaining body water found here

Answer 2

Extracellular fluid (ECF)

Question 3

What are the 2 sub compartments of ECF?

Answer 3

1. Plasma
2. Interstitial fluid (IF)

Question 4

• Anything that dissociate into ions in water
• (+) or (-) charge
• most abundant solutes
• more responsible for fluid shifts/movement of water
• ex: inorganic salts, acids and bases, some proteins, Nacl

Answer 4

Electrolytes

Question 5

• Do not dissociate in water
• No charge
• Make up the bulk of the body fluids (most of mass since they don’t dissociate)
• Ex: glucose, Urea, lipids, etc

Answer 5

Non-electrolytes

Question 6

Optimal body water content depends on

Answer 6

1. Age: infants and children have more water
2. Sex: men have higher body water content than women
3. Body fat %: fat is the least hydrated of all body tissues

Question 7

Lungs, skin

Answer 7

Insensible water loss

Question 8

Sweat, urine, feces

Answer 8

Sensible water loss

Question 9

• Controls the thirst mechanism which is activated by Osmoreceptors, dry moth and decreasing blood volume/pressure

Answer 9

Hypothalamic thirst center

Question 10

the body will always lose water, even if we never drink water

Answer 10

Obligatory water loss

Question 11

Detect changing ECF osmolarity

Answer 11

Osmoreceptors

Question 12

• decrease in ADH produced by hypothalamus or released by posterior pituitary (beginning of the brain)
• symptoms: polyuria, dilute urine, fatigue, dehydration

Answer 12

Central diabetes insipidus

Question 13

ADH is produced and released in normal amounts, but the kidneys are unresponsive to it

Answer 13

Nephrogenic diabetes insipidus

Question 14

influence water movement in body, essential for excitability, membrane permeability

Answer 14

Electrolyte balance

Question 15

NaHCO3 and NaCl account for ….. of total ECF solute

Answer 15

280 mOsm

Question 16

release causes increased reabsorption of Na+ in DCT and collecting ducts

Answer 16

aldosterone

Question 17

release causes decreased reabsorption of Na+

Answer 17

Atrial Natriuretic peptide (ANP)

Question 18

• estrogen exerts similar effect as aldosterone
• progesterone is slighlty diuretic
• more sodium being absorbe causes water to be absorbed too

Answer 18

sex hormones

Question 19

• In high plasma levels, exerts very strong aldosterone like effects
• can contribute substantially to edema
• stress response hormone

Answer 19

glucocorticoids

Question 20

• Na+ serum value is > 145 mEq/l
• caused by dehydration,exccessive intravenous NaCl administration

Answer 20

Hypernatremia

Question 21

Na+ serum value is <135 mEq/L

Answer 21

hyponatremia

Question 22

potassium secretion depends on

Answer 22

plasma concentration and aldosterone

Question 23

optimal pH of arterial blood is

Answer 23

7.4

Question 24

pH of 7.45 or higher

Answer 24

alkalosis

Question 25

pH 7.35 or lower

Answer 25

physiological acidosis

Question 25

one or more compounds that resist changes in pH when strong acids or bases are introduced

Answer 25

Chemical buffer system

Question 25

* important for ECF * Mixture of carbonic acid (weak acid) and bicarbonate salt (weak base) * Bicarbonate salt ties up free H+ from a strong acidconverted to carbonic acid

Answer 25

BiCarbonate buffer system

Question 26

important for ICF and urine

Answer 26

Phosphate buffer system

Question 27

Important in ICF and blood plasma

Answer 27

Protein buffer system

Question 28

* important for long term acid base balance

Answer 28

renal regulation

Question 29

H2CO3 in tubule cells broken down into H+ and HC03- Where does each go?

Answer 29

* H+ secreted into filtrate * HCO3- generated in tubule cell is pumped into peritubular capillary

Question 30

generate new bicarbonate ions to be pumped into plasma

Answer 30

PCT and type A intercalated cells

Question 31

in collecting ducts can secrete bicarbonate ions while reclaiming H+ from filtrate

Answer 31

Type B intercalated cells

Question 32

PCO2 > 45 mmHg Respiration is shallow/slow (hypoventilation) (not taking as many breathes and not breathing deeply) CO2 can’t be exposed of (trapped in body) Caused by: many respiratory diseases/conditions CO2 is too high, above 45 mm Hg – this much CO2 will cause the blood to be too acidic

Answer 32

respiratory acidosis

Question 33

PCO2 < 35 mm Hg Respiration is deep/fast (hyperventilation) –too many breathes per minute and breaths are too deep, so they are getting rid of too much CO2 that they need Caused by: stress/anxiety, pain Too little CO2 in blood, pH will become high or too basic

Answer 33

respiratory alkalosis

Question 34

any acid base imbalce that does not involve CO2

Answer 34

metabolic acidosis and alkalosis

Question 35

Low bicarbonate levels Common causes: excessive alcohol intake, long-term diarrhea pH is low

Answer 35

metabolic acidosis

Question 36

High bicarbonate levels Common causes: excessive vomiting, excessive base intake Takes tums or pepto---> can shift the person to metabolic alkalosis

Answer 36

metabolic alkalosis

Question 37

Blood pH below 6.8

Answer 37

CNS depression coma and death

Question 38

Blood pH above 7.8

Answer 38

overstimulated CNS muscle tetany

Question 39

Changes in respiratory rate & depth evident when lungs must compensate for metabolic imbalances

Answer 39

Respiratory compensation (not fixing the problem but is trying to balance)

Question 40

Kidneys can compensate for acid-base imbalances of respiratory origins

Answer 40

renal compensation

Question 41

For renal compensation of respiratory acidosis, the kidneys will...

Answer 41

kidneys conserve more bicarbonate ions, the more blood pH will increase back to normal level

Question 42

For renal compensation of respiratory alkalosis, the kidneys will...

Answer 42

kidneys either secrete more bicarbonate ions or simply do not reabsorb it--shift pH back down so it becomes more acidic

Question 43

For respiratory compensation 1. metabolic acidosis the lungs will... 2. Metabolic alkalosis the lungs will....

Answer 43

1. respiratory rate + depth increase This blows off excess CO2 to increase blood pH again (balancing out the low bicarbonate level) 2. respiratory rate + depth decrease Conserves CO2 to decrease blood pH to desirable level