PHGY 312 Lecture Notes - Lecture 12: Fetal Hemoglobin, Vocal Folds, Hyperventilation

• School: McGill University
• Department: Physiology
• Course: PHGY 312
• Professor: Russell Jones

Document Summary

Po2 = 35 mmhg going to the baby from the placenta. In reality, because fetus operates on steep portion on o2 dissociation curve, it"s much easier to load oxygen. If women can hyperventilate, fetus will be bigger (at high altitudes) Pleural pressure goes down in inspiration keep fluid inside the lungs. Pca opens vocal folds and is in phase with diaphragm. Ta is adductory muscle and is not active usually. Pca is silent but ta is active during periods of apnea in fetus. Fetal breathing movements control pulmonary fluid and lung development. Lung grows in centripetal fashion (from center to periphery) Dead space at birth is larger compared to total volume! Lung volume goes up as fetal pulmonary fluid until birth; after, quite a bit of fluid gets eliminated. If metabolic rate is low, ventilation will not start after birth.