Water and Sodium

Question 1

How much of your body is comprised of water?

Answer 1

60%

Question 2

How much water of body weight in ICF and ECF?

Answer 2

ICF: 40%
ECF: 20%

Question 3

Predominant cation in the ICF?

Answer 3

K+

Question 4

What is contained in the ECF? (4)

Answer 4

1) Na+
2) Chloride and bicarbonate
3) Glucose/Urea
4) Protein

Question 5

What is oncotic pressure?

Answer 5

Oncotic pressure is exerted by proteins, notably albumin, that tends to pull fluid into its solution.

Question 6

What happens to ECF osmolality after rehydrating?

Answer 6

It is restored

Question 7

What does a change in ECF result in?

Answer 7

Slower response compared to osmolality

Question 8

Common symptoms of dehydration?

Answer 8

Thirst, drymouth, weight loss

Confusion: Change in vol of brain cells, as fluid moves in and out to equalise osmolality

Question 9

What causes increased thirst in dehydration?

Answer 9

Increased plasma osmolality

Question 10

Risk of too much water? (2)

Answer 10

1) Cerebral overhydration
(Water intoxication)
2) Hyponatraemia

Question 11

What is an oedema?

Answer 11

Excess accumulation of fluid in IS

Disrupts filtration and osmotic forces of circulating fluids

Question 12

Common problems of volume overload? (5)

Answer 12

1 ECF volume expansion
2 Loss of IV fluid to IS
3 Low effective circulating volume stimulates RAAS and ADH
4 Renal Sodium retention
5 Oedema

Question 13

Difference in water movement in Hydrostatic and Oncotic pressure?

Answer 13

1) Hydrostatic: Plasma to IF

2) Oncotic: IF to Plasma (diff due to proteins)

Question 14

What are the 4 types of oedema?

Answer 14

1. Lymphatic.
2. Venous.
3. Hypoalbuminaemic.
4. Inflammatory.

Question 15

What is a serous effusion?

Answer 15

Excess water in a body cavity

Question 16

What is a Pleural effusion?

Answer 16

Disruption in balance between

1) Lymphatic drainage
2) Hydrostatic and Oncotic forces in visceral and parietal pleural vessels

Question 17

What is the transudate?

Low protein content

Answer 17

Fluid pushed through capillary due to high pressure in capillary

Question 18

What is the exudate?

High protein content

Answer 18

Fluid leaks around cells of capillaries caused by inflammation and ^ permeability of pleural capillaries to protein

Question 19

Two examples of Plasma Na disorders?

Answer 19

1) Hypernatraemia (High sodium)

2) Hyponatraemia (Low sodium)