205 L2

Question 1

Define homeostasis

Answer 1

Maintenance of the volume and composition of body fluids

Maintenance of a constant internal environment

Question 2

Define negative feedback

Answer 2

Reverse a change in the controlled condition

Question 3

Define positive feedback

Answer 3

Reinforce/amplifies the change in the controlled condition

Question 4

How much of a 70Kg male is water?

Answer 4

60%

Question 5

How much of a 70kg female is water?

Answer 5

50%

Question 6

What proportion of the total body water is intracellular fluid?

Answer 6

2/3 or 60%

Question 7

What proportion of the total body water is extracellular fluid?

Answer 7

1/3 or 40%

Question 8

What is the extracellular fluid composed of?

Answer 8

Interstitial fluid
Plasma
Transcellular fluid

Question 9

What proportion of the extracellular fluid is interstitial fluid?

Answer 9

4/5 (including transcellular fluid) or 75%

Question 10

What proportion of the extracellular fluid is plasma fluid?

Answer 10

1/5 or 20%

Question 11

What proportion of the extracellular fluid is transcellular fluid?

Answer 11

5%

Question 12

There is more potassium/sodium within the cell than there is potassium/sodium

Answer 12

There is more potassium within the cell than there is sodium

Question 13

There is more ——– outside the cell than there is ——-

Answer 13

There is more sodium outside the cell than there is potassium

Question 14

what is the osmolarity of the intracellular fluid?

Answer 14

280 mOsm - 300 mOsm

Question 15

what is the osmolarity of the extracellular fluid?

Answer 15

280 mOsm - 300 mOsm

Question 16

is chloride more extracellular or intracellular?

Answer 16

More extracellular - tends to be with sodium

Question 17

Why is it important to have different concentrations of ions in the ICF and ECF?

Answer 17

Setting the membrane potential

Generating electrical activity

Muscle contraction

Nutrient uptake via secondary active transport

Generation of intracellular signaling cascades

Question 18

How do solutes (ions) move?

Answer 18

Passive transport across a permeable membrane - Electrochemical gradient

Intrinsic membrane proteins
Pores - e.g. Aquaporins

Channels - voltage gated channels like Na/K ATPases for Ca2+

Carriers and Co Transporters - SGLT and GLUTs

Question 19

Na+/K+ ATPase is a form of —— transport. It takes —- sodium ions —- of the cell and —- potassium ions —-. Therefore there is always a —— for —– to move passively —– the cell. These are located in the ———— membrane and are ubiquitous.

Answer 19

Na+/K+ ATPase is a form of active transport. It takes 3 sodium ions out of the cell and 2 potassium ions in. Therefore there is always a gradient for sodium to move passively into the cell. These are located in the basolateral membrane and are ubiquitous.

Question 20

Na+/K+ ATPase is a form of —— transport. It takes —- sodium ions —- of the cell and —- potassium ions —-. Therefore there is always a —— for —– to move passively —– the cell. These are located in the ———— membrane and are ubiquitous. 1 ATP is converted to 1 ADP + P. One of the most important functions of the pump is to control the cell ——–.

Answer 20

Na+/K+ ATPase is a form of active transport. It takes 3 sodium ions out of the cell and 2 potassium ions in. Therefore there is always a gradient for sodium to move passively into the cell. These are located in the basolateral membrane and are ubiquitous. 1 ATP is converted to 1 ADP + P. One of the most important functions of the pump is to control the cell volume.

Question 21

Define osmosis

Answer 21

Osmosis is net diffusion of water (across a semi-permeable membrane) from a region of high water concentration to one that has a lower water concentration

Question 22

Define osmosis

Answer 22

Osmosis is net diffusion of water (across a semi-permeable membrane) from a region of high water concentration to one that has a lower water concentration

Question 23

What is osmotic pressure?

Answer 23

The amount of pressure required to stop the flow of water through a semipermeable membrane

Question 24

What is osmotic pressure?

Answer 24

The amount of pressure required to stop the flow of water through a semipermeable membrane

Question 25

If you put red blood cells into solution that has the same number of osmotically active particles, there will be — net movement of water, there is – change in cell volume, so the solution is ———.

Answer 25

If you put red blood cells into solution that has the same number of osmotically active particles, there will be no net movement of water, there is no change in cell volume, so the solution is isotonic

Question 26

If you put a cell (280mOsm) into a solution that is 180mOsm, water is going to move ——- the cell causing it to —–. This is a ——- solution

Answer 26

If you put a cell (280mOsm) into a solution that is 180mOsm, water is going to move into the cell causing it to burst. This is a hypotonic solution

Question 27

If you put a cell (280mOsm) into a solution that is 400mOsm, water is going to move —– of the cell causing it to ——. This is a ——–solution

Answer 27

If you put a cell (280mOsm) into a solution that is 400mOsm, water is going to move out of the cell causing it to shrink. This is a hypertonic solution

Question 28

If a patient has lost blood, what IV solution would you administer?

Answer 28

Isotonic IV solution because you don’t want to change the structure of the red blood cells

If the red blood cells swell they can’t move through arteries

If the red blood cells shrink can move through the glomerulus