MBBS · Paediatrics

Neonatal transition

At birth, the newborn transitions from placental gas exchange to pulmonary ventilation; lung expansion and circulation changes establish neonatal cardiorespiratory physiology.

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Alveolar gas exchange

Original conceptual SVG · scalable
ALVEOLUSair-filled spaceO₂CO₂Thin alveolar–capillary barrierPulmonary capillary bloodVentilation ≠ perfusion

Partial-pressure gradients move O₂ into pulmonary capillary blood and CO₂ toward alveolar gas; schematic, not to scale.

Concept 01

First breaths

Lung aeration reduces pulmonary vascular resistance and increases pulmonary blood flow, enabling efficient pulmonary gas exchange.

Concept 02

Circulatory adaptation

Changes in pressure and flow promote functional closure of fetal shunts. Anatomical closure occurs on differing timelines.

Concept 03

Thermoregulation

Newborns have a large surface-area-to-mass ratio and require attention to thermal balance during the transition.

Education / safety note: This is an introductory overview; neonatal resuscitation is a hands-on team skill that must be learned using approved current protocols and supervised training.

Reference and next reading

Explore the original curriculum and publisher-hosted resources for full-depth reading; this note is an original schematic introduction, not an exhaustive chapter.

Official / publisher source: NMC official CBME Curriculum 2024 and current regulations index ↗Official / publisher source: NCBI Bookshelf ↗Official / publisher source: PubMed ↗