EXAM #1: RESPIRATORY PATHOPHYSIOLOGY

Question 1

What is the major factor that controls breathing?

Answer 1

1) PCO2

+

2) PO2
3) pH

Question 2

Outline the neuro-anatomic pathway that controls breathing.

Answer 2

1) Increased PCo2
2) Central chemoreceptors
3) Central Pattern Generator
4) Spinal cord or cranial nerves
5) Respiratory muscles, chest wall/ diaphragm
6) Increased ventilation

Question 3

At what generation does cartilage stop?

Answer 3

11

Question 4

What generation marks the conducting airway/ anatomic dead space?

Answer 4

16

Question 5

Where is smooth muscle most abundant in the airway?

Answer 5

Bronchioles

Question 6

What two regions of the airway confer the greatest resistance to air flow?

Answer 6

Bronchus and bronchioles

Question 7

List four factors that will increase airflow resistance.

Answer 7

1) Inflammation of bronchial epithelium
2) Secretions
3) Constriction
4) Physical blockade

Question 8

Write the equation for resistance.

Answer 8

N/A

Question 9

What is the resistance of airflow inversely proportional to?

Answer 9

r^4

Question 10

What type of ANS receptors will increase airway resistance?

Answer 10

M3

Question 11

What type of ANS receptors will decrease airway resistance?

Answer 11

B2

Question 12

What are the obstructive pulmonary disorders?

Answer 12

1) Asthma
2) Bronchitis
3) Emphysema
4) Obstruction of the airway lumen (physical)

Question 13

List some of the disorders that will obstruct the airway.

Answer 13

Asthma 
Bronchitis 
Bronchiectasis 
Bronchiolitis 
CF 
Acute FB obstruction 
Epiglottitis 
Croup

Question 14

Describe the blood flow around an alveoli.

Answer 14

Capillaries form a SHEET of flow around the alveoli

Question 15

Describe the composition of the respiratory membrane from the alveolar side to the capillary side.

Answer 15

1) Surfactant
2) Alveolar epithelium
3) Epithelial basement membrane
4) Interstitial space*
5) Capillary basement membrane
6) Capillary endothelial cell membrane

This space is INCREASED in CHF

Question 16

What are the major components of the lung interstitial space?

Answer 16

1) Connective tissue–elastin (like a balloon)
2) Smooth muscle
3) Lymphatics
4) Capillaries
5) Cells

*Under normal conditions this space needs to be v. small

Question 17

Write the equation for the diffusion of a gas across a membrane.

Answer 17

D= Diffusion of gas 
dP= difference in partial pressure 
A= surface area 
d= distance 
S= solubility

Question 18

Which is more soluble, oxygen or carbon dioxide?

Answer 18

Co2

Question 19

What factors will alter dP?

Answer 19

1) High altitude
2) Restrictive lung disease

*Note that you can control this will an oxygen mask

Question 20

What factors will alter d?

Answer 20

1) Pulmonary edema

2) Pneumonia

Question 21

What are the major components of the parietal pleura?

Answer 21

1) Parietal lymphatics
2) Stoma opening into the pleura space
3) Systemic capillaries

Question 22

What are the components of the visceral pleura?

Answer 22

Pulmonary capillaries

Question 23

What causes pleural effusion?

Answer 23

1) CHF i.e. increased pulmonary venous hydrostatic pressure
2) Decreased oncotic pressure
- Liver disease
- Nephrotic syndrome
3) Decreased pleural pressure from atelectasis
4) Blockade of lymphatic drainage (e.g. tumor at the stoma)

Question 24

What is the definition of a restrictive lung disorder?

Answer 24

Disorders that cause decreased expansion of the lungs

Question 25

What is lung compliance?

Answer 25

Extent to which the lungs will expand with an increase in transpulmonary pressure *Note that this is the inverse of elasticity

Question 26

What are the primary intrinsic determinants of lung compliance?

Answer 26

Elastin and collagen - Increased elastin/collagen= decreased compliance - Decreased= increased compliance *Note that things like CHF and pneumonia will also decreased lung compliance

Question 27

What are the types of restrictive lung disorders?

Answer 27

1) Fibrotic interstitial lung diseases 2) Atelectatic disorders (ARDS) 3) Pleural space disorders 4) NM disorders 5) Chest wall deformities 6) Infection/inflammation

Question 28

How does the pulmonary circulation differ from the systemic circulation?

Answer 28

1) Shorter 2) Thinner/more COMPLIANT - Accommodate more volume in a shorter amount of space

Question 29

What artery is responsible for bronchial circulation? Where does the blood go after the bronchial capillaries?

Answer 29

Bronchial a. - broncial capillaries - pulmonary vein *Note that this is deoxygenated blood going to the left heart and accounts for a lower oxygen saturation of arterial blood--this is "physiological shunting"

Question 30

What is hypoxic pulmonary vasoconstriction (HPV)?

Answer 30

- Low oxygen content to alveoli - Surrounding vessels VASOCONSTRICT *Avoids perfusing hypoxic areas

Question 31

What is the normal V/Q ratio? What is the normal V/Q ratio at the apex? Base? Why?

Answer 31

Normal= 0.8 ``` Apex= 3, b/c there is wasted oxygen with less perfusion Base= 0.6 b/c there is wasted perfusion ```

Question 32

What is a V/Q of infinity? What causes it?

Answer 32

Blood flow obstruction - Think PE - OR, physiologic dead space where there is normally no gas exchange

Question 33

What is a V/Q of 0?

Answer 33

Airway obstruction, also called "shunt" *Bronchial circulation is a physiologic shunt

Question 34

What volume cannot be measured by spirometry?

Answer 34

Residual volume

Question 35

What is the normal tidal volume?

Answer 35

500 mL

Question 36

What is the total amount of air that can go in and out in a single breath?

Answer 36

Vital capacity

Question 37

What is FVC?

Answer 37

Forced Vital Capacity

Question 38

Draw the Flow-Volume curve.

Answer 38

N/A

Question 39

After one second of expiration, where are you on you the flow-volume curve?

Answer 39

FEF75 *75% of the Forced Expiratory Flow

Question 40

How will the Flow-Volume curve change in obstructive lung disease?

Answer 40

See ppt.

Question 41

How will the Flow-Volume curve change in upper airway obstuction?

Answer 41

See ppt.

Question 42

How will the Flow-Volume curve change in restrictive lung disease?

Answer 42

See ppt.

Question 43

What is a normal FEV1/FVC?

Answer 43

0.8

Question 44

What is the FEV1/FVC in obstructive lung disease?

Answer 44

Decreased i.e. less than 0.7 *Both decreased, but FEV1 more so

Question 45

What is the FEV1/FVC in restrictive lung disease?

Answer 45

Increased i.e. greater than 0.8 *Decreased FVC