Respiration 4

Question 1

What are the 2 categories of lung disease?

Answer 1

Obstructive
Restrictive

Question 2

What is an obstructive lung disease?

Answer 2

Reduction in flow through airways

Question 3

What is a restrictive lung disease?

Answer 3

Reduction in lung expansion

Question 4

What is the overall effect of lung disease?

Answer 4

A reduction in ventilation in the lungs

Question 5

Name 3 causes of obstructive lung disease

Answer 5

Excess secretions
Bronchoconstriction
Inflammation

Question 6

Why does narrowing of the airways lead to reduced flow?

Answer 6

Narrowing of the airways leads to increased resistance which leads to a decreased flow rate

Question 7

Describe the difference between a normal V/T graph and an obstructive lung disease V/T.

Answer 7

The FEV1 in an obstructive will be < 80% of FVC in obstructive lung disease

Question 8

Describe the difference between normal volume time curves and obstructive disease volume time curves

Answer 8

In obstructive disease, forced vital capacity is unchanged but there is a decrease in FEV1.
The point volume is the same but takes longer to get there.

Question 9

Describe the difference in shape in flow-volume loops in normal vs obstructive.

Answer 9

Initial and peak flow are similar
There is a sharp fall in flow-rate on obstructive - leads to a concave shape graph.

Question 10

What disease produces a persistent productive cough and excess mucus secretion?

Answer 10

Chronic bronchitis

Question 11

What disease causes hyperactive airways ?

Answer 11

Asthma

Question 12

What disease causes structural changes?

Answer 12

Chronic obstructive pulmonary disease

Question 13

What other diseases is COPD linked to?

Answer 13

Bronchitis and emphysema

Question 14

Which disease is associated with a loss of elastin?

Answer 14

Emphysema

Question 15

What is an atopic trigger?

Answer 15

An extrinsic trigger e.g. allergies

Question 16

What is a non-atopic trigger?

Answer 16

An intrinsic trigger e.g. respiratory infections

Question 17

Explain the asthma response

Answer 17

A non atopic or atopic trigger causes the asthma response.
Inflammatory cells move across the blood into the airways ->
Release of inflammatory mediators (histamine) ->
Smooth muscle has histamine receptors which trigger bronchoconstriction ->
Reduces airflow

Question 18

What is salbutamol ? What is its effect?

Answer 18

A short acting B2 adrenoreceptor used for short term treatment of asthma.
Dilation of the airways by inhibiting contraction

Question 19

Is salbutamol an agonist or antagonist?

Answer 19

Agonist, stimulates the airways

Question 20

What is a long acting asthma treatment?

Answer 20

Glucocorticoids e.g. beclomethasone

Question 21

What is the mechanism of glucocorticoids?

Answer 21

Interact with beta2 adrenoreceptors ->
Activates coupling of g proteins with adenylcyclase ->
Enhances production of cAMP which activates protein kinase A causing smooth muscle contraction

Question 22

Name 2 effects of restrictive lung disease

Answer 22

Reduced chest expansion
Loss of compliance (fibrosis)

Question 23

Describe a restrictive lung disease spirometer

Answer 23

Vital capacity is reduced compared to the predicted value

Question 24

Describe a restrictive disease volume time curve.

Answer 24

The curve is depressed
FEV1 is reduced
Reduction in vital capacity

Question 25

Describe a restrictive disease flow volume loop

Answer 25

Normal shape with a decrease in volumes of air moved Reduction in peak flow

Question 26

Explain how inhaling asbestos leads to lung disease

Answer 26

Asbestos is foreign to the body so macrophages are sent to break down the asbestos -> The body is unable to break it down, leading to a build up of fibrous tissue around the asbestos -> This leads to a loss of compliance

Question 27

Where is the basic respiratory rhythm generated?

Answer 27

Centres in the medulla

Question 28

What would a lesion between the medulla and pons lead to?

Answer 28

A maintenance in the basic breathing pattern which could be overridden.

Question 29

Which type of respiration does the dorsal axis in the medulla link to?

Answer 29

Quiet expiration

Question 30

Which type of respiration does the ventral axis link to?

Answer 30

Forced inspiration

Question 31

When is the ventral respiratory group inactive?

Answer 31

During quiet respiration

Question 32

When is the dorsal respiratory group active?

Answer 32

Spontaneously -> period of activity - shut off - period of activity Shut off period causes expiration

Question 33

What is the pre botzinger complex responsible for?

Answer 33

Inspiration

Question 34

Where is the pre botzinger complex located?

Answer 34

At the top of the dorsal respiratory group

Question 35

How does the pons influence breathing?

Answer 35

The pons has 2 centres which send signals to the medulla to regulate rate and depth of breathing.

Question 36

What in the pons increases the rate of breathing? What is its mechanism?

Answer 36

The pneumotaxic centre Inhibitory effect on the inspiration centre so shortens inspirations

Question 37

What in the pons increases the depth of breathing? What is its mechanism?

Answer 37

Apneustic centre Stimulates the inspiratory system prolonging inspirations

Question 38

Explain the hering breuer reflex

Answer 38

Stretch receptors detect the volume of lungs -> Send signal to the inspiratory centre (medulla) via the vagus nerve -> The medulla sends a signal via the phrenic nerve which causes the diaphragm to contract to prevent over inflation

Question 39

What would occur if a rise in CO2 is detected in cerebral spinal fluid?

Answer 39

Central chemoreceptors in csf detect the rise which has a larger effect on pH -> stimulation causes an increase in ventilation so pH returns to normal

Question 40

Where are peripheral chemoreceptors located?

Answer 40

Carotid body and aortic arch

Question 41

What does stimulation of peripheral chemoreceptors lead to?

Answer 41

Increased inspiration