1.4 Pulmonary Flashcards
What is the trachea?
Flexible airway with cartilage rings. It is lined with ciliated epithelium and goblet cells for mucus excretion
What are the bronchi and bronchioles?
Divisions of the trachea
What are the alveoli?
Miniature air sacs with collagen to stretch when filled with air and spring back
What is inspiration?
Active
External intercostal muscles contract whilst internal intercostals relax
The ribs pull up and out, increasing thorax volume.
Diaphragm contracts and flattens, increasing thorax volume
The increase in volume reduces pulmonary pressure.
Atmospheric Pa > Pul Pa =Air forced in
What is expiration?
Passive
Internal intercostals contract; external relax
Ribs move down and in, reducing thorax volume.
Diaphragm relaxes and domes.
Reducing thorax volume, increases pulmonary preassure.
Pul Pa>Atmospheric Pa= Air forced out
What is ventilation?
Ventilation (dm3 min-1) = Tidal Volume (per breath dm3) * Ventilation rate (min-1)
What are the features of alveoli?
Large S.A/Vol ratio- speeds diffusion rate
Thin walls- decreases diffusion pathway
partially permeable- allows gaseous material through
diffusion gradient- ventilation moves air whilst blood moves in capillaries
DISEASE: What is Pulmonary Fibrosis?
Scarred lung epithelium- reduces elasticity and thickens
Obstructs diffusion pathway
shorter ventilation
Shortness of breath
chronic cough- remove tissue
pain- increase in pressure, reduction in elasticity
fatigue- less O2 for respiration
DISEASE: Asthma?
Localised reaction due to pollutants, anxiety etc
Reduces ventiliation and diffusion gradient
resistance to flow of air
breathing difficulty- restricted airway
wheezing- air passing constriction
cough- reflex to clear obstruction
DISEASE: TB?
bacterial infectious disease (water droplets)
bacteria grow in O2 rich areas
inflammation- primary infection
post primary- scar tissue- bacteria destroys tissue
chronic cough- remove tissue
antibiotics and better health to reduce TB
DISEASE: What is emphysema?
1/5 smokers Permanently stretched elastin Alveoli burst- S.A decreased Shortness of breath- exhalation difficulty chronic cough- remove damaged tissue bluish skin- cyanosed- reduced O2 Fatigue- reduced O2 for respiration
Lung disease risk factors
smoking- 90% COPD are smokers Air pollution Genetic Infection Occupation
