Female reproductive system Flashcards
Functions of female reproductive system
Produce haploid gametes
Facilitate fertilisation
Site for implantation of embryo
Physical and nutritional needs to nurture the neonate after birth
What connects ovaries to the uterus?
The fallopian tubes
What steroid hormones do follicular cells secrete?
Granulosa - 17beta- oestradiol
Theca- progesterone
What is an oocyte?
Developing eggs enclosed in a follicle
How does smooth muscle aid the movement of an egg in the fallopian tube?
Via peristalsis
What in the fallopian cells captures the eggs?
Fimbrae
What is the structure of a fallopian tube?
Longitudinal smooth muscle layer
Circular smooth muscle layer
Highly folded mucosa- ciliated and secretory cells
What is the structure of a fallopian tube?
Longitudinal smooth muscle layer
Circular smooth muscle layer
Highly folded mucosa- ciliated and secretory cells
What are the 3 layers of the uterine wall?
Perimetrium
Myometrium
Endometrium
What layer of the uterus changes throughout the month?
Endometrium
Describe the structure of the endometrium
Simple columnar epithelial cells
Lamina propria
Compound tubular glands
Spiral arteries
Where do the spiral cells in the uterus spiral through?
Spiral arteries spiral through the lamina propria
What connects the uterus to the vagina?
The cervical canal
What do cervical glands secrete to prevent microbes?
Mucus
How long is the birth canal?
8-10cm
Describe the structure of the vaginal wall
Adventia
Muscularis
Mucosa
What epithelium is in the vagina?
Stratified squamous epithelium
What specialisation does the stratified squamous epithelium in the vagina contain?
Walls are rich in glycogen which is fermented into lactic acid to inhibit pathogens
What pH is the vagina?
3.5-4
What are the 2 neuroendocrine cycles?
Ovarian
Endometrial
What drives the menstrual cycle?
Hypothalamic-pituitary-gonadal axis
What releases gonadotropin-releasing hormone?
Hypothalamic neurons
What connects the hypothalamus to the anterior pituitary?
Hypophyseal portal system
What does G-protein coupled GnRH receptor signalling cause?
Results in exocytosis of gonadotropins (FSH and LH)
What cells does LH activate?
Theca cells
What cells do FSH activate?
Granulosa cells
What do active theca cells release?
Progesterone
What do active granulosa cells release?
Oestrogen and some progesterone
What will the hypothalamic pituitary gonadal axis produce?
Mature gametes
What receptors does GnRH bind to? Where?
Receptors on gonadotrophs in the anterior pituitary
What are ovarian steroid hormones synthesised from?
Cholesterol by ovarian follicular theca cells and granulosa cells
Function of oestrogen and progesterone?
Develop the ovum
Maintain the corpus luteum
Maintain pregnancy
Are LH and FSH stimulatory or inhibitory in the pathway of cholesterol to 17beta oestradiol?
Stimulatory
What feedback mechanism is used for 17 beta oestradiol?
Negative throughout the cycle
- except prior to ovulation when it is positive
Describe the follicular phase via feedback mechanisms
Oestrogen acts on the hypothalamus via negative feedback.
Hypothalamus wont be stimulating pituitary so will downregulate FSH and LH.
Describe the luteal phase via feedback mechanisms
Progesterone has a negative feedback on the hypothalamus
Describe the midcycle.
Follicular cell proliferation
- Oestradiol rises to critical level
- -ve feedback on GnRH changes to +ve feedback
- FSH and LH are upregulated
- Maturation of oocyte
What is the egg called when it leaves the ovary?
Corpus luteum
What is the level of FSH and LH in the follicular phase?
High
Function of the follicular phase
Increase growth of follicles
Increases oestradiol causes proliferation in endometrial layer
When does the follicular phase switch to the luteal phase?
When upregulation of LH causes ovulation
Describe the luteal phase
Progesterone is secreted which promotes endometrial gland formation.
If no fertilisation by 22 days, corpus luteum degenerates and functional layer is lost
Describe oogenesis.
Formation of eggs
By what process are oogonia produced?
Mitosis by primordial germ cells
By what process are primary oocytes produced?
Prophase of meiosis
How are oocytes release?
Alternating release from left to right ovum every month
What is folliculogenesis?
The development of the follicle to a mature egg and finally a corpus luetum
What are the stages of folliculogenesis?
Primary oocyte ->
Secondary oocyte ->
Graafian oocyte ->
Ovulation of oocyte ->
Corpus luteum or Corpus albican
When would an oocyte progress to a corpus luteum?
If the ovulated oocyte is fertilised
When would an oocyte progress to a corpus albican?
If the ovulated egg isn’t fertilised
What does the second meiotic division produce in folliculogenesis?
A haploid ovum
Where is the secondary oocyte?
In the fallopian tube
What do 17 beta oestradiol and progesterone control in the endometrial cycle?
Changes in the endometrium
Feedback regulation of FSH and LH from pituitary
Changes in the cervix and vagina
Describe the follicular phase in terms of cervical mucus
The cervix secretes mucus (regulated by 17 beta oestradiol) which creates channels to propel sperm
Describe the secretory phase in terms of cervical mucus
Progesterone decreases and the mucus becomes thick to actively block sperm
Describe the proliferative phase of the endometrial cycle
Oestrogen is dominant, LH has a rapid spike
- The wall becomes thick and stable
- The functional layer is built and then shed
- Zona basalis isn’t shed
Describe the secretory phase of the endometrial cycle
Following ovulation, Progesterone is dominant
- Thickness of endometrium decreases
- The glands increase mucus
- The stroma becomes oedematous
- Spiral arteries elongate and coil
- Ends in menses
Describe the mechanism of hormonal contraceptives
Feedback on the hypothalamus downregulates GnRH secretion
-> Inhibits feedback on anterior pituitary to inhibit FSH and LH
-> No folliculogenesis or ovulation will occur
How is progastrin affected by hormonal contraception?
Affects cervical mucus and fallopian tube motility
Cuts down on endometrial glycogen, inhibiting the support of embryonic growth
Describe the mechanism behind the morning after pill
1 - Alters the endometrium so the egg cant embed itself
2 - Thickens the mucus to prevent sperm reaching the uterus
3- Stops ovulation by release of hormones
