1) respiration - airflow

Question 1

what are the 3 types of. airflow?

Answer 1

laminar
unstable
turbulent

Question 2

what is laminar airflow

Answer 2

steady flow of solution down a tube

Question 3

what happens when flow rate increases

Answer 3

goes from laminar to transitional phase

Question 4

what is unstable airflow

Answer 4

stream disrupted causing unstable airflow, flips between laminar and turbulent

Question 5

what is flow type governed by

Answer 5

Reynolds number

Question 6

laminar flow in Re

Answer 6

Re<1000

Question 7

unstable flow in Re

Answer 7

1000-1500

Question 8

turbulent flow in Re

Answer 8

Re>1500

Question 9

what is Re in physiological conditions and why

Answer 9

Re =1

due to physiological not being long smooth tubes

Question 10

equation of Velocity in the lungs

Answer 10

V = (Palv - Patm) / R

Question 11

velocity is greatest when ?

Answer 11

expiration

Question 12

where is flow rate maximal ?

Answer 12

centre of the tube, reduces towards the edges

Question 13

what type of flow is most present in the lungs

Answer 13

turbulent flow

Question 14

what occurs if flow rate goes beyond critical value

Answer 14

get irregular currents and vortices develop

Question 15

why is more effort required for turbulent flow

Answer 15

need a greater pressure gradient to obtain same flow seen under laminar conditions

Question 16

relationship between pressure and laminar flow

Answer 16

as pressure grad increases, flow rate doesn’t change much

Question 17

relationship between pressure gradient and turbulent flow

Answer 17

as pressure grad increases, flow rate doesn’t change much

Question 18

where is the conducting zone

Answer 18

airway generation 0-16

Question 19

the trachea and bronchi have ___ velocity

Answer 19

high

Question 20

the respiratory zone ____ velocity

Answer 20

low

Question 21

upper airways have ___ flow rate and ____ flow

Answer 21

high flow rate. and turbulent flow

Question 22

terminal airways have ___ flow rate and ___ flow

Answer 22

low. and laminar

Question 23

what is COPD

Answer 23

group of progressive obstructive diseases characterised by an increase in airway resistance and decrease in airflow

Question 24

2 examples of COPD

Answer 24

chronic bronchitis - long standing inflammation of the bronchi and bronchioles, increase in mucous production
Emphysema - destruction of alveolar walls, sacs breakdown, disrupts SA

Question 25

how is COPD treated

Answer 25

bronchodilators - anticholinergics or Beta2 adrenoceptors

Glutocorticoids

Question 26

what is Poiseuille’s law

Answer 26

Airway resistance is proportional to gas viscosity and the length of the tube but is inversely proportional to the fourth power of the radius

Question 27

what does Poiseuille’s law mean

Answer 27

small changes in airway diameter = big impact on resistance and hence flow rate

Question 28

what is the normal total airway resistance

Answer 28

1.5 cm H2O .s.liters-1

Question 29

what is the total airway resistance in COPD

Answer 29

50 cm H2O …

Question 30

what factors impact airway resistance

Answer 30

increased mucous secretion - reduces airway diameter

oedema - increased fluid retention in lung tissue - swelling and narrowing of airways

Question 31

effect of dynamic pressures on airflow

Answer 31

inspiration - forced expansion of higher airways - decreases resistance
expiration - forced collapse of higher airways - increase resistance

Question 32

dynamic pressures at rest

Answer 32

functional residual capacity = 0
alveolar pressure = 0
intrapleural pressure = -5 (subatmospheric pressure in intrapleural space)

Question 33

dynamic pressures during inspiration

Answer 33

Pip = -20 (even more subatmospheric)

gradual decrease. in pressure gradient from alveoli to atmosphere

Question 34

how can patients overcome problems created by emphysema

Answer 34

slow exhalation
breathing at a higher lung volume
exhale through pursed lips

Question 35

which direction does the resistance lung vol graph shift with COPD

Answer 35

COPD is to the right of normal