C16 Electrolytes

Question 1

Intracellular

Answer 1

inside cells- 2/3 of body water

Question 2

Extracellular

Answer 2

outside cells- 1/3 of body water

Question 3

osmolarity

Answer 3

if osmoles/liter solvent, way of measuring total substances in a solution

Question 4

osmolality

Answer 4

of osmoles/kg solvent

Question 5

osmole=

Answer 5

1 mole of dissolved substance

Question 6

2 osmolality test methodologies?

Answer 6

freezing point depression & vapor pressure

Question 7

osmolality estimation

Answer 7

2 Na + (BUN/3) + (Glucose/20)

Question 8

Osmolar gap

Answer 8

difference between the (measured) osmolality & the (calculated) osmolality

Question 9

What do you suspect in an increased osmolar gap?

Answer 9

an additonal abnormal substance: ethanol, methanol, ethylene glycol (antifreeze)

Question 10

Plasma sodium accounts for what percentage of plasma osmolality?

Answer 10

90%

Question 11

What can cause diabetes insipidus?

Answer 11

ADH deficiency, without water re-absorption, 10-20 liters of urine per day

Question 12

increased osmolality are concerns for:

Answer 12

infants, unconsious pts, & elderly

Question 13

Water concentration is regulated by?

Answer 13

thirst & urine output

Question 14

Thirst & urine production are regulated by?

Answer 14

plasma osmolarity

Question 15

increased osmolality stimulates:

Answer 15

hypothalamus to stimulate the sensation of thirst, posterior pituitary secretes ADH, & ADH increases H2O absorption by renal collection ducts

Question 16

Renin-Angiotensin-Aldosterone system

Answer 16

regulates blood volume via plasma sodium

Question 17

decreased bp stimulates ___ secretion by the renal glomeruli

Answer 17

renin

Question 18

Aldosterone has 2 effects on blood volume/pressure:

Answer 18

stimulates reabsorption of sodium by the kidneys, water passively follows sodium, increasing blood volume, aldosterone stimulates vasoconstriction- increasing bp

Question 19

Sodium

Answer 19

most abundant extracellular anion (90%), main contributor to plasma osmolality, regulated by water intake/output & aldosterone