Respiratory Basics

Question 1

What are the factors of normal respiration ?

Answer 1

Inspiration
Expiration
Gaseous exchange

Question 2

What is the process of inspiration?

Answer 2

Contraction of inspiratory muscles
Enlargement of thorax
Decrease in pressure in relation to atmosphere
Air flows into the lungs

Question 3

What is the process of expiration?

Answer 3

Mostly passive, but driven by lung recoil

Expiratory muscles used during forced expiration

Question 4

Where does gaseous exchange take place ?

Answer 4

Across the alveolar-capillary membrane

Question 5

Explain the process of gaseous exchange.

Answer 5

It the process by which oxygen alveoli in lungs is delivered to the bloodstream.

It is also the elimination of carbon dioxide from blood to alveoli.

Question 6

What is atmospheric pressure ?

Answer 6

Pressure outside the body

Question 7

What is Alveolar pressure?

Answer 7

Pressure inside the lungs

Question 8

What is intrapleural pressure?

Answer 8

Pressure in the pleural space

Question 9

What are the main factors determining resistance to airflow?

Answer 9

• Type of flow
• Viscosity of gas
• Dimension of airways

Question 10

What is lung compliance ?

Answer 10

It is a measure of lungs ability to stretch and expand when there is change in volume / change in pressure

Question 11

What are the 2 different measurements of lung compliance ?

Answer 11

Static compliance & Dynamic compliance

Question 12

When is static compliance measured ?

Answer 12

When no air is moving.

It is measured at the end of inspiration before expiration

Question 13

When is dynamic compliance measured ?

Answer 13

During breathing

Question 14

What does low compliance indicate ?

Answer 14

Stiff Lung

Question 15

What is ventilation ?

Answer 15

The movement of gas in and out of the lung

Question 16

What is alveolar ventilation?

Answer 16

Gas that reaches alveoli and is part of gaseous exchange

Question 17

What is dead space ?

Answer 17

Gas that moves in and out of lung but is not part of gaseous exchange

Question 18

What is the formula for minute ventilation?

Answer 18

Tidal volume X respiratory volume

Question 19

What is perfusion ?

Answer 19

Low Pressure System

Question 20

What is perfusion affected by?

Answer 20

Gravity - creates a gradient from top down

Question 21

What is V/Q matching ?

Answer 21

It is a ratio used to assess the efficiency and adequacy of matching ventilation and perfusion.

Question 22

What is the ideal ratio of V/Q matching ?

Answer 22

1

Question 23

What would a lower ratio indicate ?

Answer 23

There is poor ventilation but adequate perfusion

Question 24

What would a higher ratio indicate ?

Answer 24

There is adequate ventilation but poor perfusion

Question 25

What does shunting indicate ?

Answer 25

Hypoxic vasoconstriction

Question 26

What are the different defences ?

Answer 26

Upper respiratory tract
Mucociliary escalator
Cough

Question 27

How does the upper respiratory tract act as a defence ?

Answer 27

Filters large particles.

Provide humidification and heats incoming air.

Question 28

How does the mucociliary escalator act as a defence ?

Answer 28

Respiratory tract is lined with epithelial cells.
Contain cilia in a fluid layer
Thicker gel layer on top
Cilia beat rhythmically propelling the secretions to the top of the respiratory tract

Question 29

When would the mucociliary defence be impaired ?

Answer 29

If there are any changes in consistency of secretions
Or
Cilia is paralysed

Question 30

What is the function of the cough ?

Answer 30

To clear blockages and excess secretions

Question 31

What are the phases of a cough?

Answer 31

Deep inspiration
Closure of glottis
Build up of pressure - active expiration against closed glottis
Sudden opening of glottis - air explodes outwards - shearing of secretions off walls of airways