Water Regulation

Question 1

What is Intracellular Fluid?

Answer 1

Fluid inside the cell - cytoplasm, makes up 2/3 of total body water

Question 2

What is Extracellular Fluid?

Answer 2

Fluid outside the cell, makes up 1/3 of total body water

Question 3

What is Plasma?

Answer 3

Fluid part of the blood, makes up 1/4 of total body water

Question 4

What is Intercellular Fluid?

Answer 4

Lymph, cerebrospinal fluid, synovial fluid (fluids in joints, ear, nose and chest)

Question 5

What is Metabolic Water?

Answer 5

Water produced from cell respiration

Question 6

What is Excretion?

Answer 6

The removal of waste products of metabolism, these products are harmful and need to be removed from the body

Question 7

What are the organs involved in Excretion?

Answer 7

1. Lungs - excrete CO2 and water as vapour
2. Sweat glands - secrete water containing by products of metabolism (salts, urea, lactic acid)
3. Alimentary canal - bile (breakdown of haemoglobin) leaves the body with faeces, most is undigested food
4. Kidneys - responsible for maintaining constant concentration of materials in body

Question 8

What role does the Kidneys play in Water Regulation?

Answer 8

• Excrete water in urine (60%)

- The function of the kidneys is to excrete (water, urea) and regulate the composition of body fluids

Question 9

What is ADH and its role?

Answer 9

• ADH constantly regulates and balances the amounts of water in the blood
• High ADH in blood plasma results in tubules being very permeable to water, then leaves the tubule and goes to the blood capillaries which leads to the decrease in water in the tubule and increases concentration of materials (solutes)
• Low ADH in blood plasma results in the tubules being not very permaeble to water and therefore does not allow blood to leave tubules resulting in an increase of water