Respiration 4 lung disease + control of respiration

Question 1

What are the 2 categories of lung disease?

Answer 1

-obstructive - reduction in flow through airway, increased resistance
-restrictive - reduction in lung expansion

Question 2

What does the ratio of FEV1 to VC tell us?

Answer 2

Gives an idea of lung health - over 80% is normal

Question 3

What is obstructive lung disease and what can it be due to?

Answer 3

-result of the airway narrowing
-due to: excess secretions, bronchoconstriction (asthma), inflammation

Question 4

What happens to resistance , FEV1 and FVC because of obstructive lung disease?

Answer 4

-increased resistance to air flow
-decrease in FEV1
-in many cases, FVC is unaltered

Question 5

What are examples of obstructive lung diseases?

Answer 5

-chronic bronchitis persistent - cough + excess mucus
-asthma - inflammatory disease
-chronic obstructive pulmonary disease (COPD) - structural changes
-emphysema - loss of elastin

Question 6

What is restrictive lung disease?

Answer 6

-reduced chest expansion due to chest wall abnormalities + muscle contraction deficiencies
-loss of compliance (fibrosis) due to normal ageing process, collagen increase + exposure to environmental factors

Question 7

What happens to VC, FVC and FEV1 because of obstructive lung disease?

Answer 7

-decrease in VC
-decrease in FVC
-FEV1 % can remain unaltered or increase

Question 8

What is asbestosis?

Answer 8

Slow build up of fibrous tissue leading to loss of compliance

Question 9

What can trigger asthma?

Answer 9

-atopic (extrinsic) - allergies, contact with inhaled allergens
-non atopic (intrinsic) - respiratory infections, cold air, stress, exercise, inhaled irritants, drugs

Question 10

What is the bodily response to asthma?

Answer 10

-movement of inflammatory cells into the airways
-release if inflammatory mediators

Question 11

What is a short acting treatment for asthma?

Answer 11

Short acting beta 2 adrenoreceptor agonists - cause dilation of airways

Question 12

What are long acting treatments for asthma?

Answer 12

-inhaled steroids - glucocorticoids act to reduce inflammatory response
-long acting beta 2 adrenoreceptor agonists

Question 13

What generates the basic respiratory rhythm?

Answer 13

Centres in the medulla

Question 14

What controls quiet inspiration?

Answer 14

Dorsal respiratory neurons

Question 15

Where is the dorsal respiratory group and what does it do?

Answer 15

-in the medulla
-controls inspiration by sending signals to the inspiratory muscles

Question 16

When is the dorsal respiratory group active?

Answer 16

Spontaneously active

Question 17

What is the ventral respiratory group and when is it active?

Answer 17

-controls inspiration + expiration
-inactive during quiet respiration
-during activation, helps control forceful inspiration + expiration

Question 18

What do the Pons do?

Answer 18

2 centres send stimuli to medulla to regulate rate + depth of breathing

Question 19

What are the 2 centres in the Pons and what do they do?

Answer 19

-pneumotaxic centre - increase rate by shortening inspirations (inhibitory effect on inspiratory centre)
-apneustic centre - increase depth + reduce rate by prolonging inspirations (stimulates inspiratory centre)

Question 20

What do stretch receptors do?

Answer 20

-Hering Breuer reflex
-stretch receptors in the lung sends signals back to medulla to limit inspiration + prevent over-inflation of lungs

Question 21

What do central chemoreceptors do?

Answer 21

-monitor conditions in cerebre-spinal fluid
-sense CO2 + pH
-indirect response to a rise in CO2 - stimulation leads to increased ventilation

Question 22

What do peripheral chemoreceptors do?

Answer 22

-respond to increased CO2, decreased pH + decreased O2
-stimulation leads to increased ventilation

Question 23

Where are peripheral chemoreceptors located?

Answer 23

In carotid body + aortic arch