Repro - Female physiology and fertilisation Flashcards
Where in the fallopian tube is the egg fertilised?
The Ampulla
What are the 3 layers of the uterus called?
Perimetrium
Myometrium
Endometrium
Which layer of the ovary contains the ovarian follicles (1 oocyte surrounded by 1 layer of cells)
The Cortex (peripheral part) - contains the primordial follicle pool which makes up the egg resevere of the ovary.
Which layer of the ovary contains blood vessels which supply the ovary?
The Medulla (central part)
Name 2 functions of the ovaries
- Oocyte production (1 mature egg generated per menstrual cycle)
- Steroid hormone production (estrogen, progesterone, testosterone)
50% of the testosterone in the female body is produced by the ovaries before menopause
a. true
b. false
a. True
Describe the structure of a primordial follicle?
Primary oocyte (stuck in the first meiotic division) surrounded by one layer of sqaumous pre-granulosa cells
Name the 4 stages of follicular development?
- Primordial Follicles
- Primary Follicle
- Seconday Follicle
- Tertiary/Graffian Follicle
Describe the structure of a primary follicle?
Oocyte surround by Zona Pellucida***
and 2 cell layers of CUBOIDAL granulosa cells (start to proliferate)
Describe the structure of a secondary follicle (pre antral)?
Oocyte grows in diamter
There are mutiple layers of granulosa cells
Appearance of Theca cells**
Describe the structure of a graffian (tertiary) follicle?
Follicular fluid between cells combine to form ANTRUM
first meiotoic division is complete -> secondary oocyte is formed and second meitoic division starts (pre-ovulatory)
Where are FSH and LH (gondaotrophins) released from?
The Anterior pituitary gland
Where do FSH and LH act upon in the female body?
The ovary
Which hormones do the the ovaries produce? and what organ do they act upon?
Estrogen and progesterone (steroid hormones)
Act on the uterus to co-ordinate the mentsrual cycle?
What structure releases GnRH?
The hypothalamus (gondotrophin releasing hormone)
Acts on the Anterior pituitary to release LH and FSH
Estrogen and Progesterone always exert negative feedback within the hypothalamic pituitary axis
a. True
b. False
False
Estrogen exerts positive feed during days 12-14 (mid-cycle) - increasing the production of GnRH, FSH and LH. This is to help mid cycle ovulation and is responsible for LH surge seen mid-cycle.
Describe the follicular phase of the ovarian cycle
FSH causes the follicle to mature and produce estrogen (inhibiting the development of other follicles)
- Follicles produce estrogen and increase thickness of endometrium
Describe the ovulation phase of the ovarian cycle
Follicle rupture and the secondary oocyte is released due to an LH surge
Estrogen is high and progesterone is low
Describe the luteal phase of the ovarian cycle
The ruptured follicle forms the corpus luteum and secretes progesterone and (some) estrogen
progesterone is high
Describe the menstruation phase of the ovarian cycle?
The corpus leteum degenerates and forms the corpus albicans
A new ovarian cycle can then begin.
Effect of estrogen on the endometrium?
proliferation
Estrogen is the primary regulator of endometrial proliferation.
During the proliferative phase, estrogen causes the endometrium to thicken and grow, preparing the uterus for pregnancy.
This phase can last 10–20 days, but is typically around 14 days.
Progesterone transforms the endometrium into a secretory structure
a. true
b. false
a. True
Ensures the structure is ready to recieve embryo.
Which hormone causes ovulation mid-cycle?
LH surge (due to positive feedback of estrogen on AP and hypothalamus)
What is menarche
The onset of bleeding - at puberty - 1st mentrual period