Respiratory

Question 1

CF inheritance

Answer 1

Autosomal recessive

Question 2

CF features

Answer 2

• Persistent cough, recurrent infections, bronchiectasis
• Pancreatic insufficiency
• Mec ileus
• Progressive lung disease
• Sweat with high salt concentration

Question 3

CF pathology

Answer 3

• Mutations of CFTR affect Na and Cl transport across cell membranes (defective Cl− and bicarbonate secretion, coupled with enhanced Na+ absorption)
• Disorder of epithelial tissue, with widespread dysfunction of exocrine glands
• Thickened mucus obstructs airways, pancreatic ducts, intestinal obstruction and biliary/liver disease.

Question 4

Acidosis and vasoconstriction

Answer 4

1 - direct: The lowered pH levels can lead to alterations in calcium ion channels and sensitivity in vascular smooth muscle cells, promoting contraction and increasing pulmonary arterial pressure.
2 - enhanced hypoxic pulmonary vasoconstriction
3 - endothelial dysfunction: disturbs balance btwn vasodilators and vasoconstrictors

Question 5

Hypoxia and vasoconstriction

Answer 5

Pulmonary arterioles constrict in response to low O2 levels (hypoxia) - this redirects blood flow to better-oxygenated areas of the lung. Chronic hypoxia leads to sustained vasoconstriction -> increased pulmonary vascular resistance (PVR) -> pulmonary hypertension.

Question 6

Kartagener (ciliary disorder) triad

Answer 6

• Chronic sinusitis
• Bronchiectasis
• Situs invertus