2.2. Hormonal Control of Reproduction Flashcards
Describe puberty.
When a child’s body goes through physical and hormonal changes that make the body capable of reproduction. The hypothalamus sends a releaser hormone to the putuitary gland which then starts producing FSH and LH in women, FSH and ICSH in men which starts the production of the gametes.
What does FSH stimulate in men?
The production of sperm in the seminiferous tubules.
What does ICSH stimulate in men?
The secretion of testosterone in the interstitial cells.
What happens when negative feedback occurs in men?
When testosterone levels in our blood reach a certain level it inhibits the secretion of FSH and ICSH. This in turn decreases the levels of testosterone in the blood which then stops the testosterone inhibiting FSH and ICSH which starts the process over again.
What does FSH stimulate in women?
The development of the female gamete, the maturation of the follicle and the secretion of oestrogen from the follicle.
What does LH stimulate in women?
Triggers ovulation and stimulates progesterone production from the corpus luteum.
What are the two phases of the menstrual cycle?
The follicular phase and the luteal phase.
What happens in the follicular phase?
The follicle begins developing, the endometrium gets repaired and gets ready for implantation. The cervix is easily penetrated in this phase. LH is produced here.
What happens in the luteal phase?
The ovum has been released and the follicle turns into a corpus luteum. Progesterone begins being secreted which prepares the endometrium for implantation. Cervical mucus thickens.
What happens when negative feedback occurs in women?
When progesterone levels are too high, it inhibits the production of FSH and LH. As they are both inhibited, ovulation is not stimulated so a corpus luteum isn’t created and progesterone levels in turn drop. Things start up again once progesterone levels decrease.
What happens in terms of hormones if fertilisation does not occur?
The corpus luteum degenerates and progesterone and oestrogen levels decrease. Menstruation occurs.
What happens in terms of hormones if fertilisation occurs?
The corpus luteum continues to secrete progesterone which helps maintain the endometrium and prevents miscarriage. After a few weeks, the placenta takes over this responsibility. FSH and LH are inhibited due to the continuous secretion of progesterone.
