Fluid Electrolyte Balance

Question 1

Fluid makeup of body

Answer 1

55-60% of adult body weight

Higher in newborns
Lower in eldery, obese

Question 2

Sources of water input

Answer 2

Ingested food, ingested liquids, metabolic water

Question 3

Water output

Answer 3

Kidneys - urine
Skin - sweat
Skin - transpiration
Expired air
GI Tract - large intestine

Question 4

Regulation of Fluid intake

Answer 4

Thirst (mainly)

Dehydration

Question 5

ADH

Answer 5

Conserves water

Question 6

Urine volume - how does it regulate water output?

Answer 6

ADH release inhibited

Fluid excreted in urine

Question 7

Fluid compartments

Answer 7

Intracellular 65%
Extracellular 35%
     Interstitial 25%
     Plasma/lymphatic fluid 8%
     Transcellular fluid 2%

Question 8

Movement of water between compartments

Answer 8

Decrease in osmolarity of interstitial fluid - causes cells to swell
Kidneys compensate - excrete excess water

Question 9

Disorders of water balance

Fluid deficiences

Answer 9

Volume depletion

Dehydration

Question 10

Disorders of water balance

Fluid excess

Answer 10

(less common)
Volume excess
Water intoxication

Question 11

Impact of water intoxication

Answer 11

Drop in interstitial Na+

Drop in interstitial osmotic pressure

Question 12

Functions of electrolytes

Answer 12

1. essential minerals
2. control osmosis between compartments
3. control acid-base balance
4. carry electric currents

Question 13

Major Ions

Answer 13

1. sodium
2. chloride
3. potassium
4. calcium

Question 14

Most abundant extracellular ion

Answer 14

Sodium 90-95% of osmolarity

Question 15

What regulates sodium?**

Answer 15

Aldosterone - reabsorption in kidneys

ANP - decrease sodium reabsorption

Question 16

Most abudnant mineral in body

Answer 16

Calcium . 98% in bone, some in plasma

Question 17

What regulates calcium?

Answer 17

Parathromone - increases reabsorption from kidneys

Question 18

Most abundant INTRAcellular ion

Answer 18

Potassium

Question 19

What regulates Potassium?

Answer 19

Aldosterone - stimulates secretion of potassium and excretion in urine

Question 20

Impact of Potassium imbalance

Answer 20

Rapid rise - (crush injury)
cardiac arrest
Slow rise - acidosis, kidney failure, etc.
depresses nerve and muscle cells

Question 21

Causes of hypokalemia (Potassium imbalance)

Answer 21

Sweating, vomiting, diarrhea