KA2 - Hormonal Control Of Reproduction Flashcards
At puberty, what secretes a releaser hormone and what does it target?
The hypothalamus secretes a releaser hormone that targets the pituitary gland
The releaser hormone stimulates the pituitary gland to release what other hormones to control the onset of puberty?
- follicle stimulating hormone
- luteinising hormone
- interstitial cell stimulating hormone
What are the 3 hormones involved in the production of sperm?
- follicle stimulating hormone
- interstitial cells stimulating hormone
- testosterone
What is the function of follicle stimulating hormone?
Promotes sperm production in seminiferous tubules
What is the function of interstitial cell stimulating hormone?
Stimulates interstitial cells to produce testosterone
What is the function of testosterone?
Stimulates sperm production and activates the prostate gland and seminal vesicles to release their secretions
What is negative feedback control?
Negative feedback control is the system of maintaining a steady state in various body systems
What is negative feedback control used for in the male reproductive system?
Regulate sperm production
What are the 4 stages involved in negative feedback control of the male reproductive system?
- FSH and ICSH released from the pituitary gland stimulate the seminiferous tubules and interstitial cells.
- This causes the interstitial cells to produce testosterone.
- High levels of testosterone have an inhibitory effect on the pituitary gland which inhibits the release of FSH and ICSH.
- Testosterone levels then decrease and the cycle begins again.
What are the 4 hormones involved in the control of the menstrual cycle?
- follicle stimulation hormone
- luteinising hormone
- oestrogen
- progesterone
How would you describe male fertility
Males are continuously fertile
How would you describe female fertility
Cyclical
What are the 2 phases of the menstrual cycle?
- follicular phase
* luteal phase
What is menstruation
Menstruation is the shedding of the endometrium, the blood lining of the uterus
When does the follicular phase occur?
The first half of the menstrual cycle
Explain the follicular phase
FSH stimulates the development of a follicle and the production of oestrogen by the follicle.
Oestrogen stimulates proliferation of the endometrium preparing it for implantation, and affects the consistency of cervical mucus making it more easily penetrated by the sperm.
Peak levels of oestrogen stimulate a surge in the secretion of LH. This surge in LH triggers ovulation.
When does the luteal phase occur?
After ovulation, during the second half of the menstrual cycle
Explain the luteal phase
LH causes the follicle to develop into the corpus luteum which secretes progesterone.
Progesterone promotes further development and vascularisation of the endometrium preparing it for implantation if fertilisation occurs.
What is vascularisation?
The process by which there is an increase in blood vessels in the endometrium making it spongy
Explain negative feedback control of the female reproductive system
High levels of oestrogen and progesterone have an inhibitory affect on the pituitary gland.
This decreases the levels of FSH and LH which prevents further follicles from developing.
If fertilisation does not occur, the ovum will degenerate which leads to the degeneration of the corpus luteum which stops secreting progesterone.
There is a subsequent drop in progesterone which leads to menstruation.
If fertilisation does occur, the corpus luteum will continue to secrete progesterone which prevents the release of FSH and new follicles developing.
