Respiratory Overview

Question 1

What are the 2 components of the respiratory system

Answer 1

Ventilation

Gas Exchange

Question 2

What common issues affect ventilation

Answer 2

Airway patency - how wide or narrow airways are

Airway muscles - ability to move the rib cage to allow ventilation to take place

Question 3

What can affect gas exchange from occurring

Answer 3

An adequate surface area which depends on an adequate number of alveoli
The thickness of the barrier between the blood vessel and gas in the alveoli - if thickness is increased, the ability of oxygen to diffuse reduces

Question 4

Describe a normal chest x-ray

Answer 4

Dark lung fields filled with air so not radiopaque
Cardiac shadow with aorta, left and right ventricle edge
Diaphragm with an elevation on one side caused by the liver

Question 5

What are the lobes of the left lung

Answer 5

Superior and inferior

Question 6

What are the lobes of the right lung

Answer 6

Superior, middle and inferior

Question 7

What is a lobectomy

Answer 7

The removal of an individual lung lobe by sectioning the airways so if a tumour is present, it can be carried out without compromising the other lobes of the lung

Question 8

What is the function of the ribs

Answer 8

Not protective - allows a change in intrathoracic volume

Question 9

What is the function of the muscles pulling on the ribs

Answer 9

Lifts them up, increasing the volume of the chest which sucks gas in through the trachea

Question 10

What does contraction of the diaphragm cause

Answer 10

An increase in intrathoracic volume

Question 11

What muscles are involved in ventilation (6)

Answer 11

Intercostals - internal and external
Muscles which run from the ribs to lower ribs - obliques 
Sternomastoid
Transverse rectus abdominus 
Accessory muscles
Major and minor pectoralis

Question 12

Describe the relationship between ability to transport gas and the radius of the vessel

Answer 12

Ability to transport gas or liquid through a tube is proportional to the power of 8 of the radius

Question 13

How is the narrowing of airways balanced in the respiratory system

Answer 13

There is an increase in the number of airways

Question 14

What signs relating to muscles show if a patient has breathing difficulties

Answer 14

Accessory muscle use - sternomastoid or more importantly pectoralis - patient will be gripping onto surfaces such as the arms of the dental chair

Question 15

What effect does inadequate ventilation have on oxygen and carbon dioxide levels

Answer 15

The level of O2 in the airways will fall and the CO2 levels will rise, this will then be mirrored in the alveoli and the ability of the patient to oxygenate and remove CO2 from the blood will be compromised

Question 16

What is type 2 respiratory failure

Answer 16

When ventilation is inadequate to deliver enough oxygen to the blood and to remove the carbon dioxide which is diffusing into the alveoli

Question 17

What happens to diseased alveoli and what effect does this have on gas exchange

Answer 17

The air sacs join up to create larger spaces with a reduced surface area so the ability of blood to become properly oxygenated and to have CO2 removed is less as there is less surface area for this to happen

Question 18

Give another reason why damage to the alveoli makes gas exchange more difficult

Answer 18

Damage occurs through either emphysema or scarring which thickens the barrier making it more difficult for gas exchange to take place

Question 19

What is the limiting factor of gas exchange when there is adequate ventilation

Answer 19

The ability of alveoli to get O2 and CO2 out of the blood

Question 20

What can cause poor gas exchange when there is adequate ventilation

Answer 20

Thickening of the alveolar wall making diffusion harder
Inadequate number of alveoli - emphysema
Mismatch between where the air goes to in the lungs and where the blood goes to in the lungs - V-Q mismatch

Question 21

What are common respiratory symptoms

Answer 21

Cough - dry or productive
Wheeze - expiration noise
Stridor - inspiratory noise
Dyspnoea - distress on effort to breathe
Pain - general or inspiratory

Question 22

What are common signs of respiratory disease

Answer 22

Chest movement with respiration
Rate of respiration 12-15/min
Air entry should be symmetrical - reduced in certain areas suggests blocking of an airway
Poor transmission of voice to stethoscope
Resonant percussion suggests air, dull sound suggests there is a lesion filling the lung area

Question 23

What are common ventilation diseases

Answer 23

Asthma
COPD
Bronchiectasis

Question 24

What are common gas exchange diseases

Answer 24

COPD (emphysema)
Pulmonary fibrosis
V-Q mismatch

Question 25

What are common inflammatory respiratory diseases

Answer 25

Cystic fibrosis

Sarcoidosis

Question 26

What are common respiratory investigations

Answer 26

Sputum examination
CXR - Chest radiograph
CT scan
Pulmonary function - Spirometry
Bronchoscopy 
VQ scan

Question 27

What do the different colours of sputum each suggest

Answer 27

Green - pus which suggests infection
Yellow/white - excess production of normal sputum which happens in asthma
Blood speckled or stained - inflammatory condition in the airways or malignancy

Question 28

What spirometry tests are commonly used as respiratory investigations

Answer 28

PEFR - maximum flow rate
FEV1 - forced expiration volume
FEV1/VC - measure of respiratory function

Question 29

Describe tidal volume

Answer 29

Normal breathing in and out

Question 30

Describe inspiratory capacity

Answer 30

Taking a big breath in

Question 31

Describe FVC

Answer 31

Breathing out from a big breath in

Question 32

Describe FEV

Answer 32

How much gas can be removed from the lungs in 1 second

Question 33

How can PEFR be used to detect asthma attacks

Answer 33

It will gradually fall leading up to an asthma attack

Question 34

What can be used for lung imaging

Answer 34

CT
PET
MRI - useful for looking at particular soft tissue lesions