Week 12 - Fluid, Electrolyte and Acid - Base Balance

Question 1

Define extracellular fluid (ECF) and intracellular fluid (ICF)

Answer 1

ECF = Fluid outside cells 
ICF = Fluid (cytosol) inside cells

Question 2

Volumes, solute concentrations are stabilised by 3 processes?

Answer 2

fluid balance
electrolyte balance
Acid - Base balance

Question 3

Define fluid balance

Answer 3

• Daily balance between amount of water gained and water lost to environment

Question 4

4 fluids in ECF

Answer 4

Lymph
Cerebrospinal fluid
Synovial fluid
serous fluid

Question 5

4 solute content of ECF

Answer 5

• Electrolytes
  
  • Proteins
  • Nutrients
  • Wastes

Question 6

Homestatic mechanisms alter ECF or ICF

Answer 6

ECF

Question 7

3 primary hormones that regulate fluid and electrolyte balance

Answer 7

• Antidiuretic hormone
  
  • Aldosterone
  • Natriuretic peptides

Question 8

Antidiuretic hormone (ADH) function

Answer 8

• Stimulates water conservation at kidneys

- Stimulates hypothalamic thirst center

Question 9

Where is ADH released

Answer 9

Hypothalamus

Question 10

Aldosterone function

Answer 10

Determines rate of sodium reabsorption and calcium loss in kidneys

Question 11

Where and why is aldosterone secreted

Answer 11

• Secreted by adrenal cortex in response to rising calcium or falling sodium level in blood

Question 12

Where and why is natriuretic peptides released

Answer 12

• Released by cardiac muscle cells in response to abnormal stretching of heart walls

Question 13

Natriuretic peptide function

Answer 13

• Reduce thirst

- Block release of ADH and aldosterone

Question 14

Define Edema (Swelling)

Answer 14

• Movement of abnormal amounts of water from plasma into interstitial fluid

Question 15

Define lymphedema

Answer 15

• Edema caused by blockage of lymphatic drainage

Question 16

2 results of ECF osmotic concentration increasing

Answer 16

1. Fluid becomes hypertonic to ICF

2. Water moves from cells to ECF

Question 17

2 results of ECF osmotic concentration decreasing

Answer 17

3. Fluid becomes hypotonic to ICF

4. Water moves from ECF into cells

Question 18

Dehydration causes the osmotic concentration of ECF to rise or fall? where does water move to and from?

Answer 18

• ECF osmotic concentration rises

- Water moves from ICF to ECF

Question 19

What 2 substances are secreted as a result of severe water loss?

Answer 19

ADH and renin

Question 20

What is the dominant cation in ECF? and cation for ICF

Answer 20

ECF = Sodium
ICF = Potassium

Question 21

Define Equivalent (Electrolyte balance)

Answer 21

amount of positive or negative ion that supplies 1 mole of electrical charge

Question 22

2 Disorders of sodium balance and their affects?

Answer 22

Hyponatremia
- Body water content rises (hyperhydration)
Hypernatremia
- Body water content declines

Question 23

2 Disorders of potassium imbalance

Answer 23

Hypokalemia
- Deficiency of potassium in bloodstream
Hyperkalemia
- Elevated level of potassium in bloodstream

Question 24

Define acidosis and alkalosis

Answer 24

Acidosis
- Physiological state resulting from abnormally low blood pH

Alkalosis
- Physiological state resulting from abnormally high blood pH

Question 25

3 types of acid in the body

Answer 25

Fixed
metabolic
volatile

Question 26

Define buffer

Answer 26

• Dissolved compounds that stabilise Ph of solution by adding or removing hydrogen

Question 27

3 major buffer systems

Answer 27

• Phosphate buffer system
  
  • Protein
  • Carbonic acid - bicarbonate

Question 28

Define renal compensation

Answer 28

• Changes in rates of hydrogen and bi - carbonate secretion or reabsorption by kidneys

Question 29

Cause of respiratory acidosis and acute

Answer 29

• Develops when respiratory system cannot eliminate all co2 generated by peripheral tissues

Acute = severe

Question 30

3 major causes of metabolic acidosis

Answer 30

1. High production of fixed or metabolic acids
   
   2. Impaired hydrogen ion excretion at kidneys
      Severe bicarbonate ion loss