(PM3A) Female Reproduction Flashcards
What are some of the roles of the female reproduction system?
(1) Gametogenesis
(2) Secretion of sex hormones
(3) Reception of sperm
(4) Fertilisation
(5) Maintenance of developing foetus + placenta
(6) Parturition – giving birth
(7) Lactation
What is the length of the female reproductive cycle?
28 days
Where in the female reproductive cycle is considered as day 1?
Day one of menstruation
What is an oocyte?
Mature egg
What occurs following mature egg release?
(1) Uterus lining (endometrium) is prepared for implantation of ovum if fertilisation occurred
(2) Uterus lining (endometrium) degenerates if fertilisation has not occurred
(3) Maturation of new follicle resumes
What happens if fertilisation of the mature egg does occur?
(1) Conceptus in uterus secretes human Chorionic Gonadotropin (hCG)
(2) This rescues corpus luteum (CL)
(3) Progesterone secretion is maintained
– this maintains endometrium (uterus lining)
– blocks FSH + LH + new follicle growth
What is the uterus?
Hosts developing foetus
Produces vaginal + uterine secretions
Passes the male sperm to the fallopian tubes
What are the ovaries?
Produce female egg cells
Produce + secrete oestrogen + progesterone
How is a mature follicle developed?
(1) Primordial follicle
(2) Primary follicle
(3) Secondary follicle
(4) Mature follicle
What are the principle hormones produced by the ovaries?
(1) Androgens – e.g. testosterone
(2) Oestrogens
(3) Progesterone
(4) Inhibin
How is oestrogen synthesised in the follicular phase?
(1) LH stimulates theca cells to synthesise androgens from cholesterol
(2) Some androgens diffuse to nearby granulose cells of follicle
(3) FSH stimulates conversion of androgens into oestrogens in granulose cells
This is known as the 2 hormone/ 2 cell mechanism
What are the phases of the ovarian cycle?
(1) Follicular phase
– Follicle maturation
– Preparation of mature egg (oocyte) release
(2) Ovulation
– mid-cycle
– rupture of follicle
– release of mature egg (oocyte)
(3) Luteal phase
– luteinisation of ruptured follicle
– preparation of reproductive tract for pregnancy if fertilisation occurs
How is the hypothalamic-pituitary-ovary axis regulated?
(1) GnRH stimulates release of LH and/ or FSH from pituitary
(2) LH + FSH stimulate release of progesterone, androgen, and oestrogen from ovaries
(3) Progesterone + oestrogen provide negative feedback on pituitary + hypothalamus
(4) Inhibits FSH + LH secretion
What is inhibin?
Peptide produced by follicle granulosa cells + corpus luteum
Selective negative feedback on FSH
What is the uterine/ endometrial cycle?
(1) Proliferative phase:
– Increased thickness of endometrium (uterus lining)
– Increased growth of endometrial blood vessels + glands
– Secretion of sperm-friendly mucous
(2) Secretory phase: – endometrial swelling –secretory development – increased blood supply – increased lipid + glycogen deposition
(3) Menstruation: – caused by sudden decrease of oestrogen + progesterone at end of luteal phase – loss of hormonal stimulation – necrosis in endometrium – aided by uterine prostaglandins
What is considered the dominant follicle?
The single follicle selected by day 6 in the follicular phase
What is a Graffian follicle?
A pre-ovulatory follicle
What happens to follicles not selected as the dominant follicle in the follicular phase?
Undergo atresia (degeneration)
Which hormone triggers ovulation?
LH from anterior pituitary
When does ovulation occur?
Within 24 hours of LH surge
How do home ovulation kits work?
Detect LH surge in urine
What does the luteinising hormone surge in ovulation cause?
(1) Swelling of follicle + thinning of wall
(2) Mature egg (oocyte) released into peritoneal cavity
(3) Mature egg (oocyte) is drawn into fallopian tube (fimbria)
(4) Remainder of follicle develops into corpus luteum
(5) Lasts for 14 days
What is menopause?
Depletion of finite ovarian reserve
Usually by age 50
Decreased production of ovarian hormones
Raised LH + FSH because no negative feedback
When does menopause occur?
Usually by age 50
Mean age of 51 in UK
