PBL 4 Flashcards
tidal volume
this is the lung volume representing the volume of air that is inhaled and exhaled in one breath measured at rest
inspiratory reserve volume
this is the maximal amount of additional air that can be drawn into the lungs by determine effort after normal inspiration
expiratory reserve volume
this is the maximal amount of addiiotnal air that can be expired from the lungs by determined effort after normal expiration
inspiratory capacity
this is the amount of air that can be inhaled after the end of a normal expiration
vital capacity
this is the maximum amount of air that can be inhaled or exhaled during a respiratory cycle, it is the sum of the expiratory reserve volume, tidal volume and inspiratory reserve volume
minute ventilation
this is the volume or air inhaled or exhaled from a persons lungs per minute
pneumatoachograph
technology that makes an accurate linear and reliable type of flow measurement spirometer
FEV1
this is how much air you can force from your lungs in one second, lower FEV-1 indicates more significant obstruction
FVC
this is the largest amount of air that you can forcefully exhale after breathing in as deeply as you can, a lower than normal FVC reading indicates restricted breathing
describe the anatomy of the lung
Right lung is split into 3 lobes, these are the superior, middle and inferior lobe
The left lung is split into 2 lobes this is because it has the heart near it
The right lung as an oblique fissure and a horizontal fissure whereas the left lung only has an oblique fissure
The left lung has a cardiac notch and T4 which goes over the heart and makes room for the heart
There is an apex and a base, apex begins 2cm above the clavicle
The lung as a pleura layer around it this is called the serous membrane , this divides into the parietal and the visceral layer, the parietal is the outer layer and is attached to the chest wall while the visceral inner layer is attached to the lungs itself
There is a gap between the parietal and visceral layer and this contains fluid that allows the lungs to expand
Pneumothorax can occur when air gets between these two layers
There are 3 zones in each lung, when looking at a clinical diagnosis you assess the function of each zone
- 23 bronchopulmonary zones
Describe mechanism of inspiration
- Diaphragm contracts and flattens
- The external intercostal muscles contract
- Internal intercostal muscles relax
- Pulls ribcage up and out
- The volume of the thoracic cavity increases
- Air pressure decreases in the thoracic cavity below the atmospheric pressure
- Air moves down the pressure gradient from outside the body to the lungs via the nostrils
- Alveolar sacs fill up with air and cause the inflation of lungs
Describe mechanism of expiration
- Diaphragm relaxes and becomes dome shaped
- The internal intercostal muscles contract
- The external intercostal muscles relax
- Ribcage moves in and down
- This decreases the volume in thoracic cavity
- The air pressure in the cavity is larger than outside the body
- Air leaves the lungs down its pressure gradient into the atmosphere
- The lungs deflate
what is spirometer and how is it used from a clinical perspective
- Spirometry is a simple test used to diagnose and monitor lung conditions by measuring how much air you can breathe out and in in one forced breath
- Main equipment used for basic pulmonary function tests
- Used to find the cause of shortness of breath
- Carried out on a spirometer which is a small machine that is attached by a cable to a mouthpiece
- During the test – soft clip placed on nose to stop air escaping from it, inhale fully so lungs are completely filled with air, close lips tightly around the mouthpiece and then exhale quickly and forcefully making sure you empty lungs fully
- Spirometry can be used to diagnose – asthma, COPD, cystic fibrosis, pulmonary fibrosis
- It can detect abnormality in lung function even when there are no signs or symptoms present
what can spirometers be used to diagnose
asthma,
COPD,
cystic fibrosis,
pulmonary fibrosis
what does the result of spirometers tell us about
- changes in lung volume
- changes in airflow
- Measures include the forced vital capacity (FVC) and forced expiratory volume (FEV)
- FVC – this is the largest amount of air that you can forcefully exhale after breathing in as deeply as you can, a lower than normal FVC reading indicates restricted breathing
- FEV – this is how much air you can force from your lungs in one second, lower FEV-1 indicates more significant obstruction
what are the effects of smoking
- Makes your blood thicker and increases chance of clot formation
- Increases blood pressure and heart rate making the heart work harder than normal
- Narrows the arteries reducing the amount of oxygen rich blood circulating to the organs
- Increase risk of heart attack or stroke
what are the effects of smoking on the lungs
- Lungs are affected badly by smoking
- Coughs, colds, wheezing and asthma are just the start
- Can cause fatal diseases such as pneumonia, emphysema and lung cancer
- 84% of deaths of lung cancer are due to smoking
- 83% if deaths of COPD is due to cancer
- COPD – collection of lung diseases including chronic bronchitis and emphysema, people with COPD have difficulties breathing due to the narrowing of the airways and destruction of lung tissue
- Symptoms of COPD include increasing breathlessness when active, phlegm and frequent chest infections
what happens after you stop smoking
20 minutes - pulse rate is normal
8 hours - Nicotine and carbon monoxide levels in blood reduce by more than half and oxygen levels return to normal.
48 hours - Carbon monoxide is eliminated from the body
Lungs start to clear out mucus and other smoking debris
No nicotine in the body and the ability to taste and smell is improved
72 hours- Breathing becomes easier, bronchial tubes begin to relax and energy levels increase
2-12 weeks - circulation improves
3-9 months - Coughs, wheezing and breathing problems improve as lung function increases by up to 10%
1 year - Risk of heart disease is about half compared with a person who is still smoking
10 years - Risk of lung cancer falls to half that of a smoker
15 years - Risk of heart attack falls to the same as someone who has never smoked
what does smoking do to the lungs
Promote goblet cell growth
Paralyzes the cilia lining the bronchi & bronchioles
Carcinogen cannot be removed from the lungs
This can lead to: Emphysema, Increased mucus,
Decreased flow rate, Obstructive lung disease,
Bronchospasm
how does nictoine act as a stimulant
Dopamine release → addiction → craving to reach same dose of dopamine
smoking an alveolar macrophages
smoking activates alveolar macrophages, and this leads to activation of neutrophils and protease (serine elastase) is released
what is alpha 1 antityrpsin
- this is a protease that inhibits the action of serine elastase
what does alpha-1-antityrpsin do
Protective role acting to reduce the breakdown of
elastin by elastase in lung tissue
Deficiency (=similar effect to smoking): pulmonary
emphysema
how do you work out minute ventilation
tidal volume and respiratory rate
