Mechanics Of Breathing

Question 1

Pulmonary surfactant

Answer 1

Lipids- 90%- DPPC, PG, other phospholipid, neutral lipids
Proteins- 8%- albumin, IgA, Apoproteins (Sp-A,B,C,D)
Carbs- 2%

Question 2

Source of surfactant

Answer 2

Type II pneumocytes.

Question 3

Synthesis and secretion

Answer 3

Palmitate, choline, glucose. In mito- DPPC. Lamellar inclusion bodies. Constitutive exocytosis. Tubular myelin, film of surfactant. Active syntheses. Some amt reuptake.

Question 4

Surfactant synthesis in fetal life

Answer 4

Starts at 34th week. 90% by 38-40 weeks.

Maturation to perinatal period.

Question 5

Regulation of synthesis and secretion

Answer 5

Hormonal- cortisol, thyroxine, insulin. 
Q&q of proteins in surfactant. SP-A
Stretching of lungs
Pharmacological agents
Exercise

Question 6

Functions of surfactant

Answer 6

Prevent lung collapse
Promote alveolar stability
Prevent edema in lungs: inward surface tension- decrease interstitial pressure
Reduce work of breathing
Immunity

Question 7

Clinical important of surfactant

Answer 7

Infant respiratory distress syndrome.
Admin of phospholipids, glucocorticoid therapy, synthesis surfactant.
Atelectasis following surgery

Question 8

Alveolar stability

Answer 8

Pulmonary surfactant
Principle of interdependence- interconnecting links.
One collapses, other gets greater expanding forces.
Major in adults