Week 9

Question 1

How heavy are the lungs

Answer 1

1kg

Question 2

What is the surface area of the lungs

Answer 2

50 - 100m2

Question 3

Describe surfactant

Answer 3

Wetting agent produced in the alveolar endothelium to reduce surface tension and increase lung compliance

Question 4

Why is the conducting zone known as the anatomical dead space

Answer 4

No alveoli

Question 5

What is a cut-off percentage for a ‘normal’ FVC/FEC1.0ratio?

Answer 5

80%

Question 6

The body supply of O2 depends on

Answer 6

Concentration

Pressure

Question 7

Air Composition of O2, N2, CO2

Answer 7

O2 = 20.93%
N2 = 79.04%
CO2 = 0.03%

Question 8

Define Torr

Answer 8

• Torr: the pressure of air molecules that raises a column of mercury in a barometer to a height of 760 mm

Question 9

Partial pressure computes as follows…

Answer 9

• Percentage concentration of a specific gas divided by total pressure of gas mixture

Question 10

Partial pressure for O2, CO2, N2

Answer 10

Oxygen - 159
Carbon dioxide - 0.2
Nitrogen - 600

Question 11

What is henrys law

Answer 11

The mass of a gas that dissolves in a fluid at a given temp varies in direct proportion to the pressure of the gas over the liquid

Question 12

2 factor that govern the rate of gas diffusion into a fluid

Answer 12

• Pressure differential between the gas above the fluid and the gas dissolved in the fluid
  Solubility of the gas in the fluid

Question 13

What creates the driving force for gas exchange across the pulmonary membrane

Answer 13

Pressure difference between alveolar and pulmonary blood gases

Question 14

amount of gas dissolved in a fluid equation

Answer 14

Quantity of gas = solubility coefficient x (gas partial pressure divided by total barometric pressure)

Question 15

Gas exchange in the lungs is dependent on what

Answer 15

Pressure gradients

Question 16

is CO2 highly soluble in plasma

Answer 16

Yes

Question 17

Pulmonary blood volume increases by how much during intense exercise

Answer 17

3x

Question 18

How much is the average PO2 in an extracellular and intracellular muscle cell

Answer 18

Extracellular - 40mm Hg

Intracellular - 46 mm Hg

Question 19

3 steps in gas exchange in the tissues

Answer 19

1. O2 diffuses to tissue
   
   2. Co2 diffuses to blood
   3. Blood returns to lungs

Question 20

Functions of oxygen transported in physical solution

Answer 20

• Establishes the PO2 of the plasma and tissue fluids
  
  • Helps to regulate breathing
    Determines oxygen loading of hemoglobin in the lungs and subsequent release in tissues

Question 21

What is the oxygen carrying capacity of hemoglobin for male and females

Answer 21

Men = 15g Hb/dL blood

- Women 14g Hb/dL blood

Question 22

Define cooperative binding

Answer 22

The joining of O2 with hemoglobin