Question

Foetal ejection reflex in a human female induces
A) Release of hormone from the placenta
B) Growth and development of ovarian follicles
C) Release of oxytocin from maternal pituitary
D) Release of gonadotropins
E) Release of prolactin from the pituitary

Answer 1

Hint: The Fergusson Ejaculation Reflex is often referred to as the foetal ejection reflex. Foetal ejection reflex involves mild uterine contractions as a woman approaches her childbirth in response to signals that come from the fully formed foetus and placenta.

Complete answer:
The human gestation period is approximately 38 weeks, followed by birth. The act of giving birth to an infant is called parturition. It begins with an increase in oestrogen/progesterone ratio, an increase in the amount of oxytocin secretion by both mother and foetus.

Parturition is caused by a complex neuroendocrine system. The mild uterine contractions arise during the childbirth in response to signals that come from the fully formed foetus and placenta. This activates the release of oxytocin from the maternal pituitary system.

Oxytocin acts on the uterine muscle which induces stronger contractions, which in turn promotes further oxytocin secretion. Stimulatory reflex between uterine contraction and oxytocin secretion tends to result in stronger and stronger contractions leading to the expulsion of the infant from the uterus through the birth canal.

The baby's weight on the cervix, and then against tissues in the pelvic floor, induces oxytocin and contractions throughout labour and delivery. The maternal pituitary helps to circulate the maternal oxytocin during pregnancy.

Thus the correct answer is option ‘C’, the release of oxytocin from maternal pituitary.

Note: In the hypothalamus, oxytocin is produced and secreted by the posterior pituitary gland into the bloodstream. The secretion depends on the electrical activity of the neurons in the hypothalamus – as these cells are excited, it is released into the blood.