Respiratory Overview Flashcards
What are the 2 components of the respiratory system
Ventilation
Gas Exchange
What common issues affect ventilation
Airway patency - how wide or narrow airways are
Airway muscles - ability to move the rib cage to allow ventilation to take place
What can affect gas exchange from occurring
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
Describe a normal chest x-ray
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
What are the lobes of the left lung
Superior and inferior
What are the lobes of the right lung
Superior, middle and inferior
What is a lobectomy
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
What is the function of the ribs
Not protective - allows a change in intrathoracic volume
What is the function of the muscles pulling on the ribs
Lifts them up, increasing the volume of the chest which sucks gas in through the trachea
What does contraction of the diaphragm cause
An increase in intrathoracic volume
What muscles are involved in ventilation (6)
Intercostals - internal and external Muscles which run from the ribs to lower ribs - obliques Sternomastoid Transverse rectus abdominus Accessory muscles Major and minor pectoralis
Describe the relationship between ability to transport gas and the radius of the vessel
Ability to transport gas or liquid through a tube is proportional to the power of 8 of the radius
How is the narrowing of airways balanced in the respiratory system
There is an increase in the number of airways
What signs relating to muscles show if a patient has breathing difficulties
Accessory muscle use - sternomastoid or more importantly pectoralis - patient will be gripping onto surfaces such as the arms of the dental chair
What effect does inadequate ventilation have on oxygen and carbon dioxide levels
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
What is type 2 respiratory failure
When ventilation is inadequate to deliver enough oxygen to the blood and to remove the carbon dioxide which is diffusing into the alveoli
What happens to diseased alveoli and what effect does this have on gas exchange
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
Give another reason why damage to the alveoli makes gas exchange more difficult
Damage occurs through either emphysema or scarring which thickens the barrier making it more difficult for gas exchange to take place
What is the limiting factor of gas exchange when there is adequate ventilation
The ability of alveoli to get O2 and CO2 out of the blood
What can cause poor gas exchange when there is adequate ventilation
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
What are common respiratory symptoms
Cough - dry or productive Wheeze - expiration noise Stridor - inspiratory noise Dyspnoea - distress on effort to breathe Pain - general or inspiratory
What are common signs of respiratory disease
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
What are common ventilation diseases
Asthma
COPD
Bronchiectasis
What are common gas exchange diseases
COPD (emphysema)
Pulmonary fibrosis
V-Q mismatch
