m11 + 12 lecture - urinary system -> fluids, electrolytes, and acid base balance

Question 1

how much of the body is made of water? (adults)

Answer 1

abt 60%

Question 2

how much of the body is made of water? (infants)

Answer 2

abt 80%

Question 3

how much of the body is made of water? (geriatric)

Answer 3

abt 55%

Question 4

where is the water/fluid that makes abt 60% of the body held in?

Answer 4

three basic compartments:
1) intracellular fluid - 80%
2) extracellular fluid- 20%
3) interstitial fluid

Question 5

what is the composition of body fluids?

Answer 5

moves by osmosis => generated by Na+ and proteins

• electrolytes and nonelectrolytes
• fluid movement is created by electrolytes (polar -> -/+ charge)

Question 6

what are electrolytes in the bodily fluids?

Answer 6

• solutes which can dissolve into water and form ions
  ex.) salts, acids, bases and some proteins

Question 7

what are nonelectrolytes in the bodily fluids?

Answer 7

• solutes which are not able to dissolve in water, and carry no covalent charge
  ex.) lipids, glucose, creatinine, urea

Question 8

how does bodily fluids move in the body?

Answer 8

• driven mostly by osmotic and hydrostatic pressures in the capillaries
  –> designed to bring abt equilibrium in different concentrations
• most active transport in the cells is devoted to maintain concentration gradients between different ions
• allows for water to move freely from one compartment to another

Question 9

sodium:

Answer 9

• extracellular
  actions: osmotic pressure, depolarization

135-145 mEq/L

Question 10

potassium

Answer 10

• intracellular
  actions: repolarization

3.5-5.5 mEq/L

Question 11

magnesium

Answer 11

• intracellular
  actions: hydrate skeletal muscle (relaxant)

1.4-2.2 mEq/L

Question 12

chloride

Answer 12

• extracellular
  actions: chloride shift (ionic balance)

95-105 mEq/L

Question 13

calcium

Answer 13

• intra and extracellular
  actions: muscle contraction, N.T. release

Question 14

HCO3-

Answer 14

• extracellular
  actions: buffer

20-29 mEq/L

Question 15

albumin

Answer 15

• extracellular
  actions: osmosis, C.O.P.

5.5-9 g/dL

Question 16

about water balance?

Answer 16

• to maintain proper water balance, we must take into our bodies as much as we lose
• most water intake is through our diet - 90%
• the rest is through metabolism

Question 17

how much water is lost each day?

Answer 17

• 2500mL per day
• intake must equal this

Question 18

how does water loss occur?

Answer 18

• urine - 60%
• insensible loss - breathing - 28%
• then in our sweat and feces

Question 19

what are disorders of water balance?

Answer 19

dehydration
- occurs when water loss is greater than water intake over a period of time
- can result in hypovolemic shock

causes: severe burns, diabetes, vomiting, diarrhea, profuse sweating, diuretics

Question 20

what is edema?

Answer 20

• swelling of the tissues caused by the movement of water into the interstitial spaces
• usually indicates tissue damage and if prolonged, tissue destruction (pitting edema)

Question 21

why does edema occur?

Answer 21

• loss of osmotic pressure (intra/extra)
• loss of circulation (CV, lymph)

Question 22

what is water toxicity?

Answer 22

• occurs when overhydrated in a short period of time
• causes symptoms resembling dehydration
• mechanism is osmosis diluting the cells and tissues to point where they cannot maintain membrane transport and essentially drown

Question 23

what is acid base balance?

Answer 23

• bc of all the bodies proteins have H attached to them, the pH of the body has to be maintained very closely —> meaning H+ regulation is important
• the buffer systems in the body then become essential to maintain pH

Question 24

what is the buffer of plasma and fluids?

Answer 24

• the buffer of the plasma and the fluids is the bicarbonate buffer system

Question 25

what is the bicarbonate buffer system?

Answer 25

HCO3-, the bicarbonate ion readily accepts a free H+
- or readily donates one
- or another of its atoms to maintain pH of the environment

Question 26

what is the protein buffer system?

Answer 26

• this occurs in the cells with intracellular proteins
• this is the most powerful buffer system in the body

Question 27

what are the compensatory systems?

Answer 27

• respiration - changes in pH due to CO2
• renal mechanism

Question 28

what does respiration due for pH?

Answer 28

• a very quick fix to changes in the pH of the plasma due to a change in the gases concentration
• CO2 - changes RR
• increased CO2 = decreased pH
• decreased CO2 = increased pH

Question 29

what is the renal mechanism?

Answer 29

• this system deals with the normal physiological acids that are regularly produced in the body
• this system is the most important in handling acid base balance

ex.) phosphoric acid, uric acid, lactic acid, glutamic acid, and ketone acids

Question 30

what are the kidneys in charge of regulating?

Answer 30

• prod. and secretion/breakdown of bicarbonate ions
• secretion and absorption of H+ –> at the nephron

Question 31

what are some problems that can occur with the kidneys regulation of bicarbonate and H+?

Answer 31

• metabolic acidosis
• metabolic alkalosis

Question 32

what is metabolic acidosis?

Answer 32

• occurs when the body has too much acid in its fluids
  caused by: severe diarrhea, renal Dz, diabetes mellitus, starvation, alcoholism, hyperkalemia

Question 33

what is metabolic alkalosis?

Answer 33

• a condition where the body’s pH level is elevated above normal due to an imbalance of acids and bases
  caused by: vomiting, antiacid overuse, diuretics, constipation, cushing’s syndrome

Question 34

when looking at a patient, what are the three things you look at to differentiate between respiratory and metabolic?

Answer 34

1) pH
2) CO2
3) bicarb

• if arrows are in the same direction = metabolic
• if arrows are in the opposite direction = respiratory