Airflow and airway resistance- Handout 3

Question 1

What is airway flow

Answer 1

ventilation

Question 2

What is the equation airflow.

Define the parameters

Answer 2

Fa= (Patm-Palv)/R

Fa=airway flow
Patm-Palv= partial pressure difference between atmosphere and alveolar
R= resistance

Question 3

How is airflow normally affected by resistance

Answer 3

normally resistance is very low and there is a small alternating between partial pressure of alveolar (-1 to 1) for air motion

Question 4

What are the types of airflow

Answer 4

laminar
turbulent
transitional

Question 5

What is laminar air flow

Answer 5

small airways close to alveoli

Question 6

What is turbulent airflow

Answer 6

trachea

Question 7

What is transitional (mixed) airflow

Answer 7

segmental bronchi

Question 8

What is poiseuille’s law

Answer 8

resistance to laminar flow is inversely proportional to the fourth power of radius

Question 9

What is the equation of poiseuille’s law; what can you infer from this

Answer 9

R= 1/r^4; that a small narrowing of the airways creates a huge increase in resistance to airflow

Question 10

What happens to resistance during an inspiration

Answer 10

the resistance falls because of a widening of the bronchial tree- the tree lengthens and widens during inspiration

Question 11

What happens to resistance during a expiration

Answer 11

the resistance rises up to 20% during expiration

Question 12

What are some chemical and physiological factors control airway constriction

Answer 12

1. parasympathetic (vagus nerves, cholinergic agonist)
2. histamine and prostaglandins
3. decrease in carbon dioxide

Question 13

What are some chemical and physiological factors that control airway dilation

Answer 13

1. beta-2 agonist (epinephrine released by the adrenals)
2. some prostaglandins
3. increase carbon dioxide

Question 14

How does the autonomic nervous system control the airways

Answer 14

the airways are innervated by the efferent (motor) fibers that constrict the bronchial smooth muscle

Question 15

How are the bronchi narrowed

Answer 15

vagal stimulation-parasympathetic fibers constrict the airways

Question 16

What are some other features of the vagus nerve

Answer 16

it also contains afferent (sensory fibers) that convey information from the lung (distension, pain, etc) tissue to the central nervous system

Question 17

Which part of the vascular system has the highest resistance

Answer 17

small arterioles

Question 18

In contrast, most resistance to airflow does not reside in terminal bronchioles. Why not?

Answer 18

tremendous branching and the large number of bronchioles; as a result the total resistance at the level of bronchioles is less than upstream

Question 19

What can lead to dangerous airflow obstruction

Answer 19

after upper airway narrowing (especially in children)

Question 20

Where does the most AIRWAY resistance occur

Answer 20

50% of the total airway resistance resides in the nose

Question 21

How do most children normally breathe

Answer 21

nose breathers

Question 22

What factors increase nasal airway resistance

Answer 22

mucus secretion

dilation, engorgement and increase in permeability of blood vesses

Question 23

What are some causes of nasal airway resistance

Answer 23

infection, allergy, sympathetic denervation (horners syndrome)

Question 24

What is rhinitis

Answer 24

irritation and inflammation of the nasal mucous membrane

Question 25

What is the action of histamine

Answer 25

one of the mediators involved in inflammatory and allergic responses that leads to fluid accumulation in the nose and congestion

Question 26

What is the action of bradykinin

Answer 26

an inflammatory substance that causes vasodilation, fluid accumulation outside of blood vessels, swelling and increase in nasal airway resistance

Question 27

What is Ludwigs angina

Answer 27

complication that can be fatal; usually from an odontogenic infection

Question 28

What are the signs of ludwins angina

Answer 28

stridor (raspy noise while breathing) muffled voice swollen tongue inability to tolerate secretions

Question 29

What is coup; who does it impact and how does it occur

Answer 29

see other slides; its a common illness with scary symptoms; viral infection of children aged six months to 3 years-can strike at night

Question 30

What are obstructive pulmonary diseases

Answer 30

disease with high airflow resistance; cant get enough air through; airflow is low and expiration takes longer time

Question 31

What are types of obstructions in the pulmonary tract

Answer 31

1. extrapulmonary-sleep apnea, croup | 2. intrapulmonary-asthma, COPD-cant get air out of lungs

Question 32

What characteristics do patients normally have with obstructions; how does that differ from patients with emphysema

Answer 32

slower peak expiratory flow

Question 33

How can you assess airflow obstruction

Answer 33

1

Question 34

What are the three main measurements of airflow

Answer 34

1

Question 35

What is the normal FEV1/FVC ratio in a normal lung

Answer 35

1

Question 36

What does obstruction do to the FEV1/FVC ratio

Answer 36

1

Question 37

What does lung fibrosis do to the FEV1/FVC ratio

Answer 37

1

Question 38

What is the break down of how many people are affected by obstructive pulmonary diseases

Answer 38

1

Question 39

``` Compare the two diseases COPD and asthma: age dyspnea FEV1/FTC RV, TLC cough smoking ```

Answer 39

1

Question 40

What are the distinctive featureso f hcho

Answer 40

1