Which of the following probably triggers the onset of labour?
Ans: a (ACTH in fetus) Ref: Ganong, 22nd ed, p. 451This also is a direct pick from self study MCQs (Chap 23 Q. 17)Mechanism responsible for onset of labour:| Circulatory estrogens due to increase in circulatory DHEAS.So |' gap junction - |' uterine contractions.| GRH by fetal hypothalamus - |' circulatory ACTH - | cortisol leading to maturation of respiratory system.(Thus in a sense fetus picks the time to be bom by | GRH & ACTH secretion)
ACTH in fetus
ACTH in mother
Oxytocin
Prostaglandin
Endocrinology and Reproduction