HHB physiology and health - gamete production and hormonal control of reproduction in females

name the structure where ova mature

the structure where ova mature is the follicle

describe the role of the follicle

a follicle surrounds the ovum, protecting the developing ovum and secretes hormones (oestrogen)

state the length of the average menstrual cycle

the menstrual cycle takes approximately 28 days

name the first phase of the menstrual cycle

the first phase is the follicular phase

describe the effect of FSH on the ovary

FSH stimulates the development of a follicle and the production of oestrogen by the follicle in the ovary

name the hormone produced by the follicle

the hormone produced is oestrogen

describe the effects of oestrogen

- causes proliferation of the endometrium to prepare for implantation
- thins the consistency of cervical mucus making it easier for the sperm to penetrate
- causes the release of LH from the pituitary gland

explain why the consistency of cervical mucus changes during the follicular phase

the change in consistency makes it easier for the sperm to penetrate through

describe what happens to the LH levels following peak levels of oestrogen

peak levels of oestrogen cause a surge in the release of LH, causing LH levels to increase

name the event which occurs following of a surge in LH

this surge in LH levels triggers ovulation

describe the process of ovulation

ovulation is the release of an ovum from a follicle in the ovary, this usually occurs around the mid-point of the menstrual cycle or at peak levels of LH
during ovulation, the body temperature rises

name the second phase of the menstrual cycle

the second phase is the luteal phase

name the structure the follicle develops into following ovulation

the follicle develops into a corpus luteum which releases progesterone

name the hormone produced by the corpus luteum

the corpus luteum produces progesterone

describe the effects of progesterone

progesterone promotes further thickening and production of blood vessels in the endometrium, this prepares the uterine lining for implantation if fertilisation occurs

identify the pituitary and ovarian hormones from a graph

describe the negative feedback effect of the ovarian hormones on the pituitary gland

high levels of oestrogen inhibits the release of FSH by the pituitary gland this prevents further follicles from developing

high levels of progesterone inhibits the release of LH and FSH from the pituitary gland, the decrease in LH causes the breakdown of the corpus luteum causing a decrease in progesterone levels which starts menstruation

describe the effect of a lack of LH

the decrease in LH causes the breakdown of the corpus luteum

describe how menstruation is triggered

due to the decrease in LH this causes a decrease in progesterone levels which starts menstruation

state the site of fertilisation in females

the site of fertilisation is the oviduct

describe the process of fertilisation

fertilisation is the fusion of the nuclei of the two haploid gametes to produce a diploid zygote which divides to form an embryo, the embryo then implants into the endometrium

state what happens to the corpus luteum and progesterone levels if fertilisation occurs

if fertilisation does occur, the corpus luteum does not break down and progesterone levels remain high