Lecture 2 & 3- Mechanics of breathing

Question 1

What is the definition of breathing

Answer 1

The bodily function that leads to ventilation of the lungs. (Also known as external respiration)

Question 2

What is the definition of ventilation

Answer 2

the process of moving gases in (inspiration) and out (expiration) of the lungs

Question 3

Definition of the ‘Mechanics of breathing’

Answer 3

describes the structural and physiological bases of ventilation

Question 4

Give three examples of obstructive lung disease

Answer 4

Asthma, COPD, lung cancer

Question 5

Give three examples of restrictive lung disease

Answer 5

Pulmonary fibrosis, pneumothorax, disorders of thoracic skeleton

Question 6

Is ΔP dependent on atmospheric pressure or pressure in the alveoli?

Answer 6

Alveoli- Atmospheric pressure remains constant

Question 7

What do the sternocleidomastoids do?

Answer 7

Elevate the sternum

Question 8

What do the neck muscles do?

Answer 8

Pull ribcage upwards

Question 9

What does scalenus major and minor muscles do?

Answer 9

elevate first two ribs and sternum

Question 10

What do the oblique, transversus and rectus abdominis muscles do?

Answer 10

pull ribcage downwards

Question 11

What do pectoralis major and latissimus dorsi do?

Answer 11

Pull ribcage outwards (by fixing shoulder girdle)

Question 12

What nerves is the diaphragm innervated by?

Answer 12

C3,4,5

Question 13

What is the definition of tidal volume

Answer 13

The volume of air breathed in/out during normal breathing

Question 14

What is the definition of residual volume

Answer 14

The volume of air left in the lungs after forced expiration

Question 15

Expiratory reserve volume definition

Answer 15

Maximum amount of air breathed out after normal inspiration

Question 16

Inspiratory reserve volume definition

Answer 16

maximum amount of air breathed in after normal expiration

Question 17

Total lung capacity definition

Answer 17

TV+IRV+ERV+RV

Question 18

Fuctional residual capacity definition

Answer 18

ERV+RV

Question 19

Vital capacity definition

Answer 19

IRV+TV+ERV

Question 20

If a patient has an FEV1/FVC ratio of below 0.7

Answer 20

Obstructive- FEV1 reduced largely

Question 21

How would you distinguish between asthma and COPD

Answer 21

In asthma FEV1 would return to normal after salbutamol (inhaler) as it is reversible

Question 22

What is the definition of compliance?

Answer 22

Change in lung volume per unit change in intrathoracic pressure- (low compliance needs high pressure for same change in volume)

Question 23

what type of cells produce surfactant

Answer 23

type II alveolar cells

Question 24

Is surfactant overproduced or deficient in respiratory distress syndrome

Answer 24

deficient

Question 25

Define the work of breathing

Answer 25

energy used in inspiration the overcome elastic forces is stored as potential energy which is dissipated in expiration