C16 Electrolytes Flashcards Preview

Clinical Chemistry > C16 Electrolytes > Flashcards

Flashcards in C16 Electrolytes Deck (19):
1

Intracellular

inside cells- 2/3 of body water

2

Extracellular

outside cells- 1/3 of body water

3

osmolarity

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

4

osmolality

# of osmoles/kg solvent

5

osmole=

1 mole of dissolved substance

6

2 osmolality test methodologies?

freezing point depression & vapor pressure

7

osmolality estimation

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

8

Osmolar gap

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

9

What do you suspect in an increased osmolar gap?

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

10

Plasma sodium accounts for what percentage of plasma osmolality?

90%

11

What can cause diabetes insipidus?

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

12

increased osmolality are concerns for:

infants, unconsious pts, & elderly

13

Water concentration is regulated by?

thirst & urine output

14

Thirst & urine production are regulated by?

plasma osmolarity

15

increased osmolality stimulates:

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

16

Renin-Angiotensin-Aldosterone system

regulates blood volume via plasma sodium

17

decreased bp stimulates ___ secretion by the renal glomeruli

renin

18

Aldosterone has 2 effects on blood volume/pressure:

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

19

Sodium

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