Fluid And Electrolytes

Question 1

Dehydration (negative water imbalance)

Answer 1

Total body water: reduced

Osmolarity: hypertonic (elevated)

Question 2

Fluid excess/ volume excess

Answer 2

Total body water: elevated

Osmolarity: isotonic (normal)

Question 3

Hypotonic hydration (positive water balance, water intoxication)

Answer 3

Total body water: elevated

Osmolarity: hypotonic (reduced)

Question 4

Lack of drinking water

Answer 4

Total body water: reduced
Osmolarity: hypertonic (up)
Form of fluid imbalance: dehydration

Question 5

Severe blood loss

Answer 5

Total body water: reduced
Osmolarity: isotonic (no change)
Form of fluid imbalance: hypovolemia

Question 6

Prolonged vomiting

Answer 6

Total body water: reduced
Osmolarity: isotonic (no change)
Form of fluid imbalance: volume depletion/ hypovolemia

Question 7

Rapid overhydration

Answer 7

Total body water: elevated
Osmolarity: hypotonic (down)
Form of fluid imbalance: hypotonic hydration

Question 8

ADH hyposecretion

Answer 8

Total body water: reduced
Osmolarity: hypertonic (up)
Form of fluid imbalance: dehydration

Question 9

Too much i.v. saline

Answer 9

Total body water: elevated
Osmolarity: isotonic (no change)
Form of fluid imbalance: volume excess

Question 10

Salts that ionize in water

e.g. NaCl—> Na++ C+

Answer 10

Electrolytes

Question 11

Charged particles

• carry currents
• fluid balance of body

Answer 11

Ions

Question 12

Contribution factors to RMP

Answer 12

• K+ out along its gradient
• Na+ in along its gradient
• active movement of 2k+ in 3Na+ by Na-K pump

Question 13

Depolarization closer to threshold

Answer 13

If cell becomes more positive

Question 14

Hyperpolarization further from threshold, harder to excite

Answer 14

If cells become more negative

Question 15

Fluid deficiency volume depletion (hypovolemia)

Answer 15

Total body water: reduced

Osmolarity: isotonic (normal)

Question 16

• Main cation of ICF

- Imbalance dangerous: [K+] ECF controls RMP

Answer 16

K+

Question 17

-low blood K+
-K+ flows out of cells
-cells hyperpolarized= less excitable
(muscle weakness, irregular heartbeat)

Answer 17

Hypokalemia

Question 18

-cells depolarized
-more excitable
(irregular heartbeat, muscle tingling)
e.g. kidney failure

Answer 18

hyperkalemia

Question 19

Ca+ balance=

Answer 19

muscle, clotting, 2nd messenger systems

Question 20

• decreased Na+ permeability of membrane
• less Na+ diffuses into cell
• cell more negative (hyperpolarized)
• inhibits nerve muscle firing

Answer 20

HYPERcalcemia (e.g. excess PTH)

Question 21

• increased Na+ permeability
• more Na+ diffuses into cell
• cell more positive (depolarized)
• nerve and muscle cells overly excitable
• tetnany, seizures

Answer 21

HYPOcalcemia

Question 22

• main cation of ECF

- since “water follow salt” main problem is swelling/shrinkage

Answer 22

Na+ balance

Question 23

cerebral edema

Answer 23

hyponatremia

Question 24

brain cells shrink

usually due to brain shrinkage

Answer 24

hypernatremia

Question 25

• main cation of ECF

- most significant solute in determining total body water and water distribution across fluid compartments

Answer 25

Na+

Question 26

• main cation of ICF

- most significant solute I determining intracellular osmolarity and cell volume

Answer 26

K+

Question 27

used as 3rd messenger system

Answer 27

Ca2+

Question 28

• released if osmolarity of ECF increases
• synthesizes aquaporins/more water rea scorned
• water conservation=concentrated water

Answer 28

ADH

Question 29

• released if K+ increases & Na+ decreases in ECF

- Na+ conservation in kidneys; “water follows salt”

Answer 29

Aldosterone