Respiratory tract

Question 1

Upper airway

Answer 1

Nose, accessory air sinuses, nasopharynx, larynx
Warm, humidify & filter air carried through the respiratory tree down to the trachea, through bronchioles and into the alveoli where gas exchange takes place

Question 2

Lower airway

Answer 2

Trachea, bronchi (have cartilage) bronchioles, terminal bronchioles (have smooth muscle), alveoli

Question 3

Infections in upper airways

Answer 3

acute inflammatory process that affects mucous membranes
eg. rhinitis, laryngitis, tonsillitis, sinusitis
symptoms = malaise, headache, sore throat, discharge
commonly viral, can get secondary bacterial infection

Question 4

Infections in lower airways - Pneumonia

Answer 4

inflammation of the lung parenchyma
exudate with inflammatory cells and fibrin in alveolar spaces
causes = infectious agents, inhalation of chemicals, chest wall trauma

Question 5

Categories of pneumonia

Answer 5

Community acquired -
elderly population, strep. pneumonia most common organism, flu and staph, aureus
Hospital acquired -
usually bacterial gram negative staph aureus
severe and can be fatal, symptoms = fever, increase WBC, chest x-ray changes
Aspiration pneumonia -
develops after inhalation of foreign material
elderly, stroke, dementia, anaesthetic
usually R middle and R lower lobe
oral flora positive
Chronic pneumonia
Necrotizing pneumonia

Question 6

Obstructive disorders

Answer 6

characterized by partial/complete obstruction at any level from trachea to respiratory bronchioles
pulmonary function test = limitation of maximal airflow rate during forced expiration

Question 7

Restrictive disorders

Answer 7

characterized by decreased expansion with decreased total lung capacity
Forced vital capacity is reduced = amount of air that can be blown out after maximal inspiration
heterogenous group of diseases
inflammation and fibrosis of the pulmonary connective tissue

Question 8

COPD - emphysema (obstructive)

Answer 8

irreversible enlargement of airspaces distal to terminal bronchiole
destruction of walls
types = centriacinar/panacinar /paraseptal / irregular
morphology = voluminous lungs, large alveoli, large apical bullae
symptoms = SOB, cough, wheezing, weight loss, congestive heart failure

Question 9

COPD - chronic bronchitis (obstructive)

Answer 9

for at least 3 months in a 2 year period
long-standing irritation by inhaled substances
hypertrophy of submucosal glands in trachea & bronchi = increased goblet cells
mucus hypersecretion and alteration in small airways = chronic airway obstruction
morphology = mucous membrane swelling, excessive secretions, narrowing of bronchioles
symptoms = persistent cough, SOB, hypercapnia (o2 retention)

Question 10

Asthma (obstructive)

Answer 10

chronic inflammatory disorder of the airways causing SOB, bronchoconstriction, wheezing, cough, chest tightness
partially reversible with treatment
extrinsic = response to inhaled antigen)
intrinsic = non-immune mechanism eg exercise, cold, aspirin
atopic = IgE mediated hypersensitivity
morphology = lung overinflation, thick mucous plug in bronchi

Question 11

Bronchiectasis (obstructive)

Answer 11

permanent destruction and dilation of airways associated with severe infections and obstructions
aetiology = CF, TB, measles, bronchial obstruction
morphology = dilated, inflamed airways
symptoms = persistent cough sputum

Question 12

Restrictive lung disease

Answer 12

morphology:
xray = bilateral infiltrative lesions, small nodules, irregular lines
scarring and gross destruction of the lung = end stage/honeycomb lung
clinical features;
tachypnea, crackles, eventual cyanosis, decrease in gas diffusing capacity, lung volume and compliance
can lead to R sided heart failure

Question 13

Vascular disorders - pulmonary embolism

Answer 13

blockage of main/branchpulmonary artery of an embolus
source of embolus are DVT of the leg
morphology = central/peripheral emboli, pulmonary haemorrhage/infarction
symptoms = pleuritic chest pain, SOB, hypoxia, increased pulmonary vascular resistance

Question 14

Vascular disorders - pulmonary oedema

Answer 14

accumulation of fluid in the air space and parenchyma of the lungs
haemodynamic oedema = increased venous pressure eg L ventricular failure
morphology = initial fluid accumulation
engorged alveolar capillaries, pink precipitate
heavy, wet lungs
alveolar microhaemorrhages
symptoms = SOB, pink sputum

Question 15

What are the 2 types of respiratory failure

Answer 15

Type 1: hypoxia with normal/low PCO
> pneumonia
> pulmonary oedema
> asthma
> pulmonary fibrosis
Type 2: hypoxia with high PCO2 
> asthma/COPD/OSA
> decreased pulmonary drive
> neuromuscular disease
> thoracic wall disease