Module 1A: Physiology of Ventilation (Davis)

Question 1

Definition:
Maintenance of homeostasis (normal regulating normal)

Answer 1

Physiology

Question 2

What is “respiration”?

Answer 2

• Utilization of oxygen in cellular metabolism (oxidative phosphorylation)
  - Generates most of cellular energy (ATP)
  - Major product is CO2
• Exchange of O2 and CO2 between organism and external environment

Question 3

Required for normal gas exchange:
Getting air into and out of alveoli

Answer 3

Alveolar ventilation

Question 4

Required for normal gas exchange:
Between the alveolar lumen and alveolar capillary blood

Answer 4

Bidirectional diffusion of O2 and CO2

Question 5

Required for normal gas exchange:
Transport of O2 to tissues and CO2 from tissues via blood

Answer 5

Perfusion of metabolizing tissue

Question 6

(T/F) Aveolar ventilation, bidirectional diffusion of O2 and Co2, and perfusion of metabolizing tissue must occur in the same place, at the same time, and in the correct amounts

Answer 6

True

Question 7

What generates an active signal to breath?

Answer 7

Central nervous system

Question 8

Triphasic:
Ribs expand and diaphragm contracts

Answer 8

Inspiration

Question 9

Triphasic:
Ribs contract and diaphragm relaxes

Answer 9

Expiration

Question 10

What ventricle pumps blood around pulmonary circulation and through alveoli over the same time period?

Answer 10

Right ventricle (RV)

Question 11

P – denotes partial pressure of a particular gas
Subscript “a” denotes partial pressure in …

Answer 11

artery
- ranges can be affected

Question 12

P – denotes partial pressure of a particular gas
Subscript “A” denotes partial pressure in …

Answer 12

alveoli

Question 13

P – denotes partial pressure of a particular gas
Subscript “v” denotes partial pressure in …

Answer 13

vein

Question 14

Normal body systems keep arterial blood gases (ABGs) within fixed limits
- Mean Value: 95
- Normal Range: 80-110
This is …

Answer 14

Pa O2 (mm Hg)
- more variation

Question 15

Normal body systems keep arterial blood gases (ABGs) within fixed limits
- Mean Value: 40
- Normal Range: 35-45
This is …

Answer 15

Pa CO2 (mm Hg)

Question 16

Lower Airways:
- Trachea to terminal bronchioles
- No gas exchange

Answer 16

Conducting Zone

Question 17

Lower Airway:
- Repiratory bronchioles to alveolar saccules
- Site of gas exchange

Answer 17

Respiratory Zone

Question 18

Alveoli – gas interface
- Synthesize pulmonary surfactant
- Divide to replace damaged ATI cells
These are …

Answer 18

Small numbers of alveolar type II (ATII) cells

Question 19

Mechanisms of gas movement:
- Non-random movement from high total pressure to low total pressure
- Movement of air into and out of lungs during ventilation
- Total pressure of alveoli (PA) < total atmospheric pressure (Pa) on inspiration

Answer 19

Bulk Flow

Question 20

Mechanisms of gas movement:
- Random movement from high partial pressure to low partial pressure
- Dependent on the composition of gas

Answer 20

Diffusion

Question 21

Factors that determine PA CO2:
- Decreased V’A (hypoventilation) will increase PACO2 as less fresh air dilutes CO2 entering alveoli from blood

This is describing …

Answer 21

Rate of alveolar ventilation

Question 22

Determinants of lung volume:
- Lung volume (VL) depends on …
- Pressure difference between inside and outside lungs (given relative to inside of lungs)

Answer 22

Transpulmonary pressure (PTP)
- PTP + PA - PIP (intrapleural fluid pressure)