While the ovum is on its way to the uterus, a successful mating results in the presence of sperm cells in the fallopian tube. On
e of these sperm cells fertilizes the ovum. How does this event affect the corpus luteum? A) The corpus luteum signals the uterus to shed its endometrium.
B) The corpus luteum stops producing progesterone and degenerates.
C) The corpus luteum continues secreting progesterone, which helps support the embryo.
The right answer is C) The corpus luteum continues secreting progesterone, which helps support the embryo.
After ovulation, Graaf's follicle becomes a yellow body, which is maintained by the action of HCG after fertilization. The yellow corpus luteum is a major hormonal source during the first weeks of pregnancy (progesterone, estrone and oestradiol). HCG maintains the corpus luteum until the placenta is sufficiently developed to take over.
This first trimester period is dependent on HCG, it represents a dangerous period or may occur spontaneous interruptions of pregnancy given the delicate transition from ovarian hormonogenesis to materno-placento-fetal hormonogenesis.
