Water and Electrolytes

Question 1

Definition of solutes

Answer 1

Dissolved substances in solution

Question 2

Which organs receive the most water?

Answer 2

1. Brain

2. Kidneys

Question 3

2 types of fluid compartments:

Answer 3

1. Intracellular

2. Extracellular

Question 4

What are the two subdivisions of extracellular fluid?

Answer 4

1. Plasma

2. Interstitial fluid

Question 5

How much water is in the intracellular fluid?

Answer 5

28L

Question 6

How much water is in the extracellular fluid?

Answer 6

14L

Question 7

What is the predominant electrolyte of the ICF?

Answer 7

K+

Question 8

What controls the concentration of electrolytes in the blood?

Answer 8

Kidneys

Question 9

Definition of electrolyte:

Answer 9

Any ions that regulate the electric charge on cells and the flow of water across its membranes

Question 10

What do cells use electrolytes for?

Answer 10

1. Maintain voltages across cell membranes

2. Carry electrical impulses

Question 11

What is the most common cause of electrolyte imbalances?

Answer 11

Renal failure

Question 12

3 types of dehydration:

Answer 12

1. Hyponatremic
2. Hypernatremic
3. Isonatremic

Question 13

Definition of osmolarity:

Answer 13

The number of solute particles per L of fluid

Question 14

What is hyponatremia caused by?

Answer 14

Excess water (IV fluids, diuretics)

Question 15

What is the risk of hyponatremia?

Answer 15

Over hydration (headache, confusion)

Question 16

What is hypernatremia caused by?

Answer 16

Not enough water (diuretic, diarrhoea, vomiting)

Question 17

What is hyponatremia?

Answer 17

Low serum sodium levels (too much water to sodium)

Question 18

What is hypernatremia?

Answer 18

High serum sodium levels (too little water to sodium)

Question 19

Predominant electrolytes in ECF?

Answer 19

Na+, Cl-, HCO3-

Question 20

What controls serum calcium levels?

Answer 20

1. Vitamin D

2. Parathyroid hormone

Question 21

What does hypercalcaemia lead to:

Answer 21

1. Fits
2. Vomiting
3. Polyuria
4. Calcification of tissues (if persistent)
5. Renal stones

Question 22

What causes hypercalcaemia?

Answer 22

1. primary hyperparathyroidism
2. Extensive skeletal metastases
3. PTH-like secretions from tumours
4. Hypervitaminosis D

Question 23

What causes hypocalcaemia?

Answer 23

1. Removal of parathyroid glands
2. Renal disease
3. Vitamin D deficiency
4. Intestinal malabsorption

Question 24

What does hypocalcaemia lead to?

Answer 24

1. Tetany - neuromuscular hypersensitivity

muscle spasms

Question 25

When will K+ accumulate excessively?

Answer 25

1. Extensive tissue necrosis

2. Renal failure

Question 26

What is the risk of high serum K+ levels?

Answer 26

Heart attack

Question 27

How does tissue necrosis cause high serum K+ levels?

Answer 27

Damaged tissues mean K+ is released from cells into extracellular fluids, making levels dangerously high

Question 28

What causes hyperkalaemia?

Answer 28

1. Extensive tissue necrosis
2. Renal failure
3. Acidosis
4. Diuretic inhibitors

Question 29

What is the risk of hyperkalaemia?

Answer 29

Cardiac arrest

Question 30

What causes hypokalaemia?

Answer 30

1. Vomiting
2. Diarrhoea
3. Cushing’s disease
4. Alkalosis
5. Diuretics

Question 31

What are the risks with hypokalaemia?

Answer 31

1. Weakness of muscles

2. Heart dysrhythmia

Question 32

What is hypokalaemia?

Answer 32

Low serum potassium

Question 33

What is hyperkalaemia?

Answer 33

High serum potassium

Question 34

How much water is in the interstitial fluid?

Answer 34

11L

Question 35

How much water is in the plasma?

Answer 35

3L