Respiratory Phys Review

Question 1

Describe the chemical control of respiration

Answer 1

metabolic change –> peripheral chemoreceptors–>respiratory center–>spontaneous rhythmic discharge to motor neurons–>respiratory muscles

Question 2

what is the key cellular layer that adds to resistance to air flow?

Answer 2

smooth muscle layer

Question 3

what is the most influential factor of the Reynold’s formula in resistance to airflow?

Answer 3

radius to the 4th

Question 4

please list 4 changes to the respiratory passageways in obstructive disease

Answer 4

1. inflammation of bronchial epithelium - bronchitis
2. secretion from epithelium - asthma, infection
3. constriction of smooth muscle - asthma
4. physical blockade - tumors, aspiration FB

Question 5

what are the 3 main factors of air resistance that can change through either disease state or medications?

Answer 5

bronchiolar size, PNS, SNS

Question 6

What are the diseases/medications associated with each change?

Answer 6

1. bronchiolar size: asthma, bronchitis
2. PNS: M3 increased - asthma, muscarinic agonists
3. SNS: B2 decreased - epinephrine and albuterol

Question 7

list 3 types of obstructive lung disease

Answer 7

obstruction of the…

1. airway wall
2. lung parenchyma
3. airway lumen

Question 8

what consists of the respiratory unit

Answer 8

1. respiratory bronchiole
2. alveolar ducts
3. atria
4. alveoli

Question 9

what makes up the respiratory membrane

Answer 9

1. surfactant
2. alveolar epi
3. epithelial basement membrane
4. interstitial space
5. capillary basement membrane
6. capillary endothelial membrane

Question 10

what is in the lung interstitium

Answer 10

1. connective tissue
2. smooth muscle
3. lymphatics
4. capillaries
5. cells - fibroblasts (collagen and elastin)

Question 11

what is the function of collagen

Answer 11

limits lung distensability

Question 12

what is the function of elastin

Answer 12

major contributor to elastic recoil of the lung

Question 13

What factors influence diffusion across the respiratory membrane?

Answer 13

Directly related to…

1. partial pressure btwn alveoli and blood
2. surface area for gas exchange (atelectasis/tumor)
3. solubility

Indirectly related to…

1. distance btwn the 2 sides of the membrane
2. molecular weight of the molecules

Question 14

What are some unique features of the visceral pleura?

Answer 14

• microvessels are further away from the surface
• supplied by the bronchial circulation
• no drainage for pleural fluid

Question 15

what are some unique features of the parietal pleura

Answer 15

• microvessela are closer to the surface
• supplied by the intercostal arteries
• have somata - exit points for pleural fluid, proteins, cells

Question 16

please list the ways in which you can have increased rate of formation of pleural fluid

Answer 16

• increased pulmonary venous pressure (most common - CHF)
• decrease in microvascular oncotic pressure
• decrease in pressure in the pleural space (atelectasis)
• increase in microvascular permeability
• fluid from the parietal cavity (diaphragm lymph)

Question 17

please list ways in which you can have decreased rate of clearance of pleural fluid

Answer 17

• systemic venous hypertension

- blockage of clearance

Question 18

compliance is the inverse of elasticity or recoil

Answer 18

true

Question 19

lung compliance reflects distensability of the lungs

Answer 19

true

Question 20

what are the 2 things compliance is determined by

Answer 20

1. elastin and collagen

2. elastic forces of surface tension

Question 21

what are the 4 categories of restrictive lung disease

Answer 21

1. lung parenchyma
2. pleural space
3. neuromuscular, chest wall, obesity
4. infection of inflammation of the lungs

Question 22

list 2 examples of lung parenchymal disorders

Answer 22

• fibrotic interstitial disease

- atelectasis

Question 23

list 2 examples of pleural space disorders

Answer 23

• pneumothorax

- pleural effusion

Question 24

list 2 examples of neuromuscular, cw, obesity disorders

Answer 24

neuro: polio, MS, MG, Guillain Barre Syndrome
CW: kyphosis, ankylosing spondylitis, flail chest

Question 25

which circulation is the largest vascular bed in the entire body?

Answer 25

-pulmonary circulation

Question 26

what is the function of the bronchial circulation

Answer 26

- 1-2% of CO going to the lungs - some of it goes to the LA = phys shunt - majority goes back into the RA for oxygenation

Question 27

what are some conditions that cause hypoxic vasoconstriction

Answer 27

1. airway obstruction 2. failure of ventilation 3. acute lung damage 4. high altitude

Question 28

What is the alveolar PO2 that would cause hypoxic vasoconstriction

Question 29

what the normal value of V/Q

Answer 29

0.8

Question 30

what is dead space and give an example of a disease state that has this

Answer 30

- dead space is ventilation of lungs that are not perfused | - an example is pulmonary embolism

Question 31

what are the main symptoms of a PE

Answer 31

1. hypoxemia 2. CP 3. hypotension (RV failure)

Question 32

what is a shunt

Answer 32

portion of the CO or blood flow tha tis diverted or rerouted - V/Q = 0

Question 33

please list 3 types of shunt

Answer 33

1. physiologic 2. L-->R 3. R-->L

Question 34

describe R --> L shunts

Answer 34

- always hypoxic | - cannot be corrected by increasing O2

Question 35

describe L-->R shunts

Answer 35

- do not cause hypoxemia | - some causes: PDA, traumatic injury

Question 36

what is the residual volume

Answer 36

- volume of gas left in the lungs after maximal forced expiration - determined by muscles of expiration and the inward elastic recoil of the lungs - cannot be measured by spirometry

Question 37

where does expiratory reserve volume begin

Answer 37

- at the END of TV | - therefore ERV = FRC - RV

Question 38

define FRC

Answer 38

- ERV + RV - this is because you do not typically use your expiratory reserve volume - represents the balance point btwn inward elastic recoil of the lungs and outward elastic recoil of the cw

Question 39

what values cannot be measured by spirometry

Answer 39

RV, FRC, TLC

Question 40

what is TLC determined by?

Answer 40

strength of contraction of the inspiratory muscles and inward recoil of the lungs

Question 41

What is a normal FEV1/FVC?

Answer 41

0.8

Question 42

what are the changes to FEV1 and FVC in obstructive disease

Answer 42

Ex: asthma | -both decrease but FEV1 decreases more, therefore ratio is

Question 43

what are the changes to FEV1 and FVC in restrictive disease

Answer 43

Ex: alveolar fibrosis - both decrease but FVC decreases more so that ratio either stays the same or increases - same or more than 0.8