Week 7: Respiratory System

Question 1

Definitions of the main 4 COPDs (chronic obstructive pulmonary disease)- main causes and consequences.

Answer 1

COPD: Impaired airflow due to complete or partial obstruction at any level of the bronchial tree

Bronchial Asthma, Chronic Bronchitis, Bronchiectasis, Emphysema

Question 2

Bronchial Asthma

Answer 2

Hyper-reactive airways  bronchospasm due to smooth muscle contraction

• Chronic inflammatory disorder
• Oedematous bronchial walls
• Excessive mucous secretion
• Symptoms: Dyspnea, coughing, wheezing, increased chance of developing other forms of COPD

Intrinsic or Extrinsic

Question 3

Chronic Bronchitis

Answer 3

Persistent productive cough that lasts for at least 3 months in at least 2 years.

CAUSE: smoking Loss of cilia Goblet cell hyperplasia leads to increased mucus Proliferation of smooth muscle Thickening of bronchial walls Chronically Inflamed airways= Airways become obstructed

Question 4

Bronchiectasis

Answer 4

Irreversible and progressive dilatation of bronchi & bronchioles. Smoking, obstruction and infection:
* Destruction of elastic and muscle
* Chronic necrotising infection of the bronchi and bronchioles
* Congenital/hereditary disease

Question 5

Emphysema

Answer 5

Irreversible and progressive destruction of alveolar walls without obvious fibrosis.
* Airspaces become abnormally enlarged – over-inflation
* Inflammation and loss of elasticity
* Most often effects the upper lobes
* Lungs can expand, but deflate poorly

CAUSE: Chronic bronchitis, asthma, coal dust exposure, smoking, genetics
Genetic: autosomal recessive defect leading to deficiency of α-1-anti-trypsin

Inflammation & smoking also inhibit α-1-anti-trypsin

COMPLICATIONS: Right-sided heart failure. Pneumothorax  atelectasis