2.2 gamete production and hormonal control of reproduction in females Flashcards
What is the primary function of the ovaries?
Gamete production
What do the ovaries contain?
Immature ova in various stages of development
What surrounds each ovum in the ovaries?
A follicle
What is the role of the follicle surrounding the ovum?
Protects the developing ovum and secretes hormones
What is fertilisation?
The fusion of the nuclei of two haploid gametes to produce a diploid zygote which divides to form an embryo
Mature ova are released into the oviduct where they may be fertilised by sperm.
What is the approximate duration of the menstrual cycle?
Approximately 28 days
The first day of menstruation is regarded as day one of the cycle.
What hormone does the pituitary gland release during the follicular phase?
FSH (Follicle Stimulating Hormone)
FSH stimulates the development of a follicle and the production of oestrogen.
What effect does oestrogen have during the follicular phase?
Stimulates proliferation of the endometrium and affects the consistency of cervical mucus
It prepares the endometrium for implantation and makes cervical mucus more easily penetrated by sperm.
What triggers ovulation?
A surge in the secretion of LH (Luteinising Hormone)
Peak levels of oestrogen stimulate this surge.
When does ovulation typically occur in the menstrual cycle?
Around the mid-point of the menstrual cycle
Ovulation is the release of an egg (ovum) from a follicle in the ovary.
What happens to the follicle during the luteal phase?
It develops into a corpus luteum which secretes progesterone
Progesterone promotes further development and vascularisation of the endometrium.
What is the role of progesterone in the luteal phase?
Promotes further development and vascularisation of the endometrium preparing it for implantation
This occurs if fertilisation happens.
What is the negative feedback effect of ovarian hormones?
Inhibit the secretion of FSH and LH by the pituitary
This prevents further follicles from developing.
What happens if fertilisation does not occur?
The corpus luteum degenerates, leading to a drop in progesterone levels and menstruation
The lack of LH is a contributing factor.
Fill in the blank: The release of an egg from a follicle is known as _______.
Ovulation
Ovulation occurs during the menstrual cycle.
