W 03 Museum Visit Flashcards
How does the size of a child lung differ from an adult lung?
Smoller in size: Child lungs smaller, including bronchial passages and alveoli. Children’s lungs have a much smaller size and volume
Smaller airway: means it’s easier to get obstructed
Drug transport: A larger proportion of drug can go down to the alveoli for adults
The interface: of is also smaller -> may decrease the rate of drug absorption
Why children need lower dose compared with adults for lungs condition?
Children absorb less drug as their airways are smaller and thus better at filtering out particulates (however, this means there could be more side effects as more drugs are stuck at the back of the throat). Less of the drug will travel to the blood/air barrier and be absorbed. Dose for children would need to be lower than adult dose to reduce toxicity.
What challenges do you anticipate if you want to deliver drugs to the lung?
Protective mechanisms of the lungs: removes particles
Mucociliary escalator: which is composed of a mucous lining layer which covers the surface of the trachea, bronchi and bronchioles, including the terminal bronchioles and which is moved upward towards the pharynx by the ciliated epithelium where it is generally swallowed - hence we aren’t inhaling dust, it pumps dust upwards
Cough response in the upper airways; makes dust be expelled
Phagocytic cells which scavenge particulate material which penetrates to the alveolar region of the lung; these cells will engulf the dust/kill it
Patient preferences - they don’t like to take drugs that way (adherence)
The structure of the respiratory system with its complex system of branching tubes of progressively decreasing size, turns and decreased airflow. However, this also makes drug delivery harder
Dissolution of material and removal by blood or lymphatics.
Requires appropriate inhaler technique
How do the diameter and surface area change if you progress from trachea to alveoli?
Diameter: smaller
SA: bigger
Why absorption would be better in respiratory system?
Increases in vasculature and decreases in thickness so absorption would be better in the lower respiratory tract.
What are the advantages of respiratory delivery for treating lung diseases compared to oral and parenteral delivery?
Bypass first pass metabolism
Local delivery: for local diseases (decrease the dose) with reduced systemic side effects (Increased concentration at the site)
Quicker absorption :rate to the blood (in comparison to oral)
Non-invasive - in comparison to IV
Rapid onset of action
Similar or superior therapeutic effect: at a fraction of the systemic dose: for e.g., 100 - 200 μg of a salbutamol by inhalation is therapeutically equivalent to 2 - 4 mg of salbutamol oral dose (tablet)
What are the distinct features of COPD and asthma lungs?
Inside airways are inflamed and swollen, as airways tighten and thicken up.
The airways become filled with mucus
Mucous gland hyperplasia (enlargement of an organ due to overproduction of cells), subepithelial fibrosis
What are the distinct features of smokers’ lungs?
Why is it dangerous if alveoli become coated with tar after smoking cigarettes for a long time?
Alveoli are the main area for gas exchange
In a smoker’s lungs, tar coats the breathing tube and the alveoli. This leads to coughing, making it harder for gas exchange to happen
=> decrease in O2 to blood => multi- organ effect
Smoker Lung = dark and mottled and texture of two also differs, with damaged lungs being harder.
Black spots
What are the distinct features of emphysema lungs?
air sacs (alveoli) in our lungs get damaged and are eventually destroyed
less oxygen reaches blood
What are the distinct features of cystic fibrosis lungs
Thickened wall
The lung becomes rigid and cannot inflate and deflate normally
Bronchi are thick-walled and filled with pus
Mucus- traps bacteria
What are the distinct features of tuberculosis lungs
Development of abnormal cell death
Distortion and irregularities of the bronchi
Caseation (a type of cell death: where the tissue becomes a dry mass with holes) tuberculosis pneumonia
Covered by dense fibrous adhesions.
Microorganism forms a cyst in the lungs
What are the distinct features of pneumonia lungs?
Grey due to grey hepatisation - RBC disintegrated, paler, neutrophils and fibrin remains, consolidation (alveoli not separate, hard to distinguish), covered in fiber
Inflammation of the airspaces in the lungs
Lower lobe can become red and congested
What are the distinct features of malignant lungs?
Black cancerous spots
Lumps
Pleomorphic (different shape) hyperchromatic (different colors) cells with abundant melanin production and abundant mitoses.
Enlarge lungs and spread cancer.
ASTHMA Vs COPD
COPD: coused by smoking Asthma: caused due to inflammatory reaction
COPD: Progressive. Asthma: Reversible
COPD: Quality of life is usually poor. Asthma: good
COPD: Ongoing mucus production Asthma: Not always
