[Control and development of breathing, pathophysiological aspects].

Abstract

The respiratory control system guarantees acid-base-homeostasis as well as the rhythmic activities of the respiratory motor system in accordance with exercise and behavioural programmes of the human being. Cortical patterns and synchronized respiratory patterns with tracheal flow and pressure variations in the fetus indicate the common network of respiration and sleep-wake mechanisms in an early stage already. During fetal life acid-base-homeostasis is dependent on progesterone controlled mechanisms. CO2 partial pressure of the uterine artery reduces to 32 mmHg. The O2 Partial pressure of the umbilical vein is 25-30 mmHg only. The raise of PCO2 during delivery is accompanied by a shower of sensory input to the reticular formation causing arousal and the opening of the lungs. The continuation of postnatal breathing is the consequence of the integration of the central chemosensitive mechanism and the reticular activating system at an adequate threshold. Perinatal defense reflexes, functional patterns and strategies in early life may outline later pathophysiological mechanisms for sleep apnea, apparently life threatening event (ALTE), sudden infant death, and congenital central hypoventilation syndrome.