KA2 Hormone control of reproduction Flashcards
What are hormones?
Chemical messengers that are secreted into the blood stream
What controls the onset of puberty?
At the onset of puberty, the hypothalamus produces a releaser hormone which targets the pituitary gland
Which hormones are released from the pituitary gland?
FSH (men and women)
ICSH (men)
LH (women)
What does FSH promote in males?
FSH stimulates the production of sperm by the seminiferous tubules in the testes
What does ICSH promote in males?
ICSH stimulates the production of testosterone by the interstitial cells in the testes
What are the roles of testosterone?
Stimulates the production of sperm,
Stimulates the seminal vesicles and prostate gland to produce their secretion (semen)
What happens when there are high concentrations of testosterone?
At high concentrations it inhibits the secretion of FSH and ICSH by the pituitary gland, this is an example of negative feedback control
What are the four female hormones included in the menstrual cycle?
FSH (pituitary) Oestrogen (ovarian) LH (pituitary) Progesterone (ovarian) Think FOLP
How long does a woman’s menstrual cycle last?
28 days, the first day of menstruation is regarded as day one of the cycle
What does FSH do? (In women)
FSH stimulates the development/ maturation of a follicle within the ovary
FSH stimulates ovary cells to produce the hormone oestrogen
What does oestrogen do?
Oestrogen stimulates the proliferation of the endometrium preparing it for implantation of a blastocyst.
Oestrogen affects the consistency of cervical mucus making it more easily penetrated by sperm.
What stimulates a surge in the secretion of LH?
Oestrogen
What does LH do?
LH triggers ovulation
LH causes the development of the corpus lutuem
LH also stimulates the corpus lutuem to produce the hormone progesterone
What does progesterone do?
Progesterone stimulates the vascularisation of the endometrium into a spongy layer rich in blood vessels.
What is the negative feedback control in women?
Progesterone inhibits the secretion of FSH and LH from the pituitary gland. This prevents further follicles from developing.