Renal - Function 1/2

Question 1

What are the functions of the kidney?

Answer 1

(Know 4)

Regulate water and electrolyte balance

Regulate arterial pressure

Excrete metabolic waste/foreign chemicals

Regulate blood pH

Regulate erythrocyte production

Regulate hormone production (vitamin D)

Regulate blood glucose

Question 2

How does the regulation of water and electrolyte balance affect the arterial pressure? What is its impacts on the body?

Answer 2

Controlling water and electrolyte removal/retainership over the long term lower/increases blood pressure

Question 3

How does the kidney regulate pH?

Answer 3

It removes/retains HCO3- and H30+

Question 4

What is the overarching role of the kidney?

Answer 4

To maintain the homeostasis

Question 5

What happens when the kidney doesn’t function?

Answer 5

Swelling, high blood pressure, shortness of breath, fatigue, nausea

Question 6

What is the role of the kidney in the cardiovascular system?

Answer 6

It controls how much blood goes into the heart

Question 7

How does water move within the body?

Answer 7

By osmosis

Question 8

What is osmosis?

Answer 8

The movement of water through a selectively permeable membrane form an area of lower solute concentration (i.e. high water concentration) to an area to higher solute concentration (i.e. lower water concentration)

Question 9

What is osmotic pressure?

Answer 9

The pressure required to prevent net water movement (i.e. pressure required to stop water moving through selectively permeable membrane)

Question 10

What is osmolarity?

Answer 10

A measure of the osmotic pressure exerted by the individual solution across a selectively permeable membrane compared to pure water per volume (i.e. 150mM NaCl into 1L of water = 150mML-1 of Na+ and Cl- therefore ~300mOsmL-1)

Question 11

What is osmolarity dependent on?

Answer 11

The number of particles in solution (not the nature of the particles)

Question 12

What are the three types of relative osmalrity? What do they mean?

Answer 12

Hyperosmotic - A solution with a higher relative osmolarity than another solution (i.e. it has a higher concentration of solutes)

Isosmotic - Where two solutions have the same osmotic pressure (i.e. both solutes have the same concentration of solutes)

Hyposmotic - Where a solution has a relatively lower osmotic pressure (i.e. it has a lower concentration of solutes)

Question 13

What is tonicity?

Answer 13

The combine effects of the osmotic pressures and a cells permeability to a solute

Question 14

If a cell was put into an isotonic solution of NaCl, what would the affect be? Why?

Answer 14

There would be no cell expansion because the osmolarity is the same so there is not net water movement and cells are relatively impermeable to NaCl so it can’t diffuse across

Question 15

If a cell was put into an isotonic solution of urea, what would the affect be? Why?

Answer 15

There would be cell expansion because, even though they are isosmotic meaning no movement of water from osmosis, there is a lower concentration of urea in the cell than outside the cell and urea is highly permeable. This means that urea can diffuse into the cell which causes water to follow it to maintain osmolarity

Question 16

What are the three types of relative tonicity? What do they mean?

Answer 16

Hypertonic (high POsm) - A solution with a higher partial osmotic pressure (POsm), i.e. the water will move into the solution as it has a higher concentration of solutes

Isotonic (same POsm) - the two solution have the same POsm, i.e. same concentration of solutes so no water movement

Hypotonic (low POsm) - a solution has a lower POsm than another, i.e. the solution has a lower concentration of solutes/higher concentration of water so water moves out of it

Question 17

How do relative POsm interact?

Answer 17

When one solution has a higher POsm it exerts a greater pressure on the lower POsm solution so water moves down the pressure gradient

Question 18

What is the percent of fluid in males and females? Why are they different?

Answer 18

55% fluid for female, 60% for males

Less for females because they have more fat cells

Question 19

What is the intracellular and extracellular distribution of fluid?

Answer 19

Intra = 2/3, extra = 1/3

Question 20

What is the distribution of extracellular fluid?

Answer 20

Interstitial = 4/5, Blood plasm = 1/5

Question 21

If you were to drink 1L of isotonic fluid, where would this go in the body? Why?

Answer 21

1L would go into the extracellular fluid, of that 200ml into the blood, 800ml into the interstitial fluid and NONE into the intercellular fluid

This is because the osmotic pressure (POsm) of the isotonic fluid is the same as the intercellular fluid (hence isotonic) so its equal concentration gradient doesn’t allow for water movement

Question 22

I you were to drink 1L of water (hypotonic solution), where would this go in the body? Why?

Answer 22

1L would be distributed throughout the body; 2/3 into the intracellular fluid, 1/3 into the extracellular fluid (4/5 of this into the interstitial fluid, 1/5 into the plasma)

The water is hypotonic (high water concentration, low solute). As the membranes are selectively permeable the solutes of the cell cannot pass through into the hypotonic solution, however water from the hypotonic solution by osmosis can move into the cells

Question 23

What are the major sources of water intake?

Answer 23

Metabolism (8%), food (28%) and beverages (64%)

Question 24

What are the major sources of water output?

Answer 24

Faeces (4%), lungs (12%), skin (24%) and urine (60%)

Question 25

What are the sources of water input that are controlled and uncontrolled?

Answer 25

Controlled: Beverages and food

Uncontrolled: Metabolism

Question 26

What are the sources of water output that are controlled and uncontrolled?

Answer 26

Controlled: Urine

Uncontrolled: Feces, lungs and skin

Question 27

What are the three main ion in the body fluid?

Answer 27

K+, Na+, Cl-

Question 28

Where is the concentration of Na+ high or low in the bodies fluid?

Answer 28

High: Blood plasma, interstitial fluid

Low: Intracellular fluid (inside the cell FYI)

Question 29

Where is the concentration of K+ high or low in the bodies fluid?

Answer 29

High: Intracellular fluid

Low: Blood plasma, interstitial fluid

Question 30

Where is the concentration of Cl- high or low in the bodies fluid?

Answer 30

High: Blood plasma, interstitial fluid

Low: Intracellular fluid (inside the cell FYI)

Question 31

How much blood is filtered every day?

Answer 31

~180L