10- Introduction of Respiratory Physiology

Question 1

V

Answer 1

Gas volume

Liters (L) or milliliters (ml)

Question 2

Q

Answer 2

Blood volume

Liters (L) or milliliters (ml)

Question 3

P

Answer 3

Pressure of a gas, in a gas or in a liquid

Millimeter of mercury (mmHg) (torr)
or
Centimeter of water (cmH2O)

Question 4

F

Answer 4

Concentration of a gas in a gas phase

Fraction Percent

Question 5

C

Answer 5

Concentration of a gas in a liquid, either in chemical equilibrium or dissolved
Percent by volume (vol % )or milliequivalent per liter (mEq/L)

Question 6

S

Answer 6

Saturation of hemoglobin with oxygen

Percentage (%)

Question 7

f

Answer 7

Breathing frequency

Breaths per minute

Question 8

Symbol
I 
E
A
B
v
c
a

Answer 8

Description

Inspired

Expired

Alveolar

Barometric

venous

Capillary

arterial

Question 9

Eupnea

Answer 9

normal breathing at rest

Question 10

hyperpnea

Answer 10

increased breathing

Question 11

hypopnea

Answer 11

decreased breathing

Question 12

dyspnea

Answer 12

awareness of breathing, uncomfortable breathing

Question 13

tachypnea

Answer 13

increased frequency of breathing

Question 14

hyperventilation

Answer 14

breathing in excess of requirements of metabolism resulting in decreased PaCO2

Question 15

hypoventialation

Answer 15

breathing insufficient for requirements of metabolism resulting in increased PaCO2

Question 16

hypoxia

Answer 16

reduced oxygen in inspired air

Question 17

hypoxemia

Answer 17

reduced oxygen in arterial blood

Question 18

hypercapnia

Answer 18

increased PACO2 or PaCo2

Question 19

Apnea

Answer 19

cessation of breathing

Question 20

periodic breathing

Answer 20

alternate periods of increased and decreased breathing

Question 21

primary function of respiratory system

Answer 21

• Delivery of oxygen from the atmosphere to the tissues

* Delivery of carbon dioxide from the tissues to the atmosphere

Question 22

Pathway of O2

Answer 22

• Atmosphere to Alveoli
• Alveolar to Pulmonary (passive diffusion depending on pressure differences)
• Capillary Pulmonary to Systemic Capillary (requires energy to move blood from heart to lungs)
• Systemic Capillary to tissues (passive diffusion of O2 in and CO2 out)

Question 23

Avogadro’s Hypothesis

Answer 23

for all gases, an equal number of molecules in the same space and at the same temperature will exert the same pressure

Question 24

dalton’s law

Answer 24

in a gas mixture, the pressure exerted by each individual gas in a space is independent of the pressures of the other gases in the mixture

Question 25

two determinants of pressure

Answer 25

• number of molecules

- temperature

Question 26

boyles law

Answer 26

As a gas is compressed, its volume decreases in exactly the same proportion as its pressure increases
(P1V1 = P2V2)

Question 27

Charle’s Law

Answer 27

If the volume of a gas is kept constant, the pressure of the gas is proportional to the temperature.

-temperature determines kinetic energy of these molecules

Question 28

gas pressure

Answer 28

force created when gas molecules strike an object

Question 29

PO2 and PCO2 Changes Along Transport Pathway

Answer 29

Atmosphere-Alveolar Changes due to:

• Dead space
• functional residual volume (we dont completely empty lungs with each exhale)
• continuous O2 utilization and CO2 production

Question 30

PO2 and PCO2 Along Transport Pathway

Answer 30

-PaO2 is slightly less than
P O due to Venous A2
admixture

-Mixed venous PO2 is less than PaO2 due to O2 utilization

Arterial and mixed venous PCO2 values change less than PO2 values
– Differences between the O2 and CO2 dissociation curves

Question 31

Lungs Determine Alveolar and Arterial Gases

Answer 31

-When hemoglobin is reduced from the normal of

15 to 7 g%, arterial blood gases are normal.

Question 32

Difference between gas pressure and gas content in blood

Answer 32

• Gas pressure is force created by kinetic energy of dissolved gas molecules striking an object.
• Gas content is total amount in blood which includes dissolved and that bound to hemoglobin which has no kinetic energy.

Question 33

If lungs are healthy, anemia does not affect PaO2 but decreases O2 content.

Answer 33

Normal
PaO2 = 100 mmHg Hemoglobin = 15 g/100 ml Content = 20 ml/100 ml

Anemic
PaO2 = 100 mmHg
Hemoglobin = 7.5 g/100 ml
Content = 10.0 ml/100 ml

Question 34

dissolved O2 =

Answer 34

solubility coefficient X PaO2.

Question 35

hemoglobin bound =

Answer 35

[hemoglobin] X 1.34 X SaO2.