Female Reproductive System Flashcards
1
Q
Endometrium - inner layer of womb, e_________ c____, thick layer of _________ tissue
Myometrium - middle layer of womb, ______ muscle = contracts
Perimetrium - most outer layer of womb, connective tissue and epithelial cells
A
Endometrium - inner layer of womb, epithelial cells, thick layer of connective tissue
Myometrium - middle layer of womb, smooth muscle = contracts
Perimetrium - most outer layer of womb, connective tissue and epithelial cells
2
Q
________ = first menstrual cycle → after 450 ovulations → ________ = end of cycle
- > primordial follicles left by this time
- F________ A_______ ⇒ death of follicles
- follicular growth comes in waves
- death rate/growth will determine reproductive life span of women
A
menarche = first menstrual cycle → after 450 ovulations → menopause = end of cycle
- > primordial follicles left by this time
- FOLLICULAR ATRESIA ⇒ death of follicles
- follicular growth comes in waves
- death rate/growth will determine reproductive life span of women
3
Q
ogenesis = oogonia → ova
- number of oogonia fixed in utero
- during fetal period oogonia (stem cells) multiply by mitosis
- meiosis begins in fetal life but is not completed until fertilisation
- Primary oocyte begin the first meiotic division BUT stop at prophase I
Puberty initiates the continuation of oogenesis and fertilization by sperm causes second meiotic division to occur
Meoisis I results in two daughter cells: a large cell called a secondary oocyte and a small cell called a first polar body
Meiosis II results in four cells: the secondary oocyte when penetrated by sperm divides into and ovum and a second polar body and the first polar body divides into two more polar bodies
A
4
Q
Follicular Phase - Primordial Follicles
A
Follicular Phase - Primordial Follicles
- simple structure
- developing oocyte surrounded by specialised epithelial cells
- appear through interaction of gametes and somatic cells
5
Q
Follicular Phase - Primary Follicles (Preantral Stage)
A
Follicular Phase - Primary Follicles (Preantral Stage)
- oocyte begins to grow
- produces cellular + secreted proteins
- initiates secretion of ZP1, ZP2 and ZP3 → forms zona pellucida
6
Q
Granulosa Cells
- _________ and ___ stimulate granulosa cells to secrete chemical messengers
- secrete _______ (supress FSH expression)
- transport __ + p______ (support maturation) to oocytes interior
- secrete oestrogen derived from androgens synthesised on _____ cells
- manufacture and secrete p_________
A
Granulosa Cells
- oestrogen and FSH stimulate granulosa cells to secrete chemical messengers
- secrete inhibin (supress FSH expression)
- transport AA + pyruvate (support maturation) to oocytes interior
- secrete oestrogen derived from androgens synthesised on theca cells
- manufacture and secrete progesterone
7
Q
Follicular Phase - Secondary Follicles (early antral stage)
A
Follicular Phase - Secondary Follicles (early antral stage)
- 10-25 follicles from preantral/early antral are developed further
- after 7 days, one is selected to develop to full maturity
- follicular growth and development is stimulated by FSH and oestrogens secreted by the follicles
8
Q
Follicular Phase - Graafian Follicle
A
Follicular Phase - Graafian Follicle
- meiosis 1 occurs
- oocyte floats on antrum
9
Q
Luteal Phase - Ovulation
- triggered by abrupt rise in plasma __ levels
- ovulation: flow of antral fluid that moves oocyte to _____ _______
- corpus luteum: ruptured follicle turns into a _____, secretes oestrogens and progesterone
- if oocyte not fertilised, corpus luteum reaches max activity within __ ____ and degenerates
- corpus albicans: formation of ____ ______
A
Luteal Phase - Ovulation
- triggered by abrupt rise in plasma LH levels
- ovulation: flow of antral fluid that moves oocyte to ovary surface
- corpus luteum: ruptured follicle turns into a gland, secretes oestrogens and progesterone
- if oocyte not fertilised, corpus luteum reaches max activity within 10 days and degenerates
- corpus albicans: formation of scar tissue
10
Q
Endocrine Function
- granulosa cells express ___ ________ but are dependant on factors from the oocyte to grow
- no ovarian hormones are produced at this early stage in the follicular development
- thecal cells are like Leydig cells in the male - the express LH receptors and produce androgens
- Main difference → thecal cells produce androstenedione instead of testosterone and at this stage this is minimal
A
Endocrine Function
- granulosa cells express FSH receptor but are dependant on factors from the oocyte to grow
- no ovarian hormones are produced at this early stage in the follicular development
- thecal cells are like Leydig cells in the male - the express LH receptors and produce androgens
- Main difference → thecal cells produce androstenedione instead of testosterone and at this stage this is minimal
11
Q
Folliculogenesis
- recruited primordial follicle grows + develops into a s________ g______ f_______ with the potential to either ovulate its egg into the oviduct at mid-cycle to be fertilised or to die by atresia
- growth is by c___ p__________ and the formation of follicular fluid
- development involves cytodifferentiation of all the cells and tissue of the follicle
- only a few follicles survive to complete the cytodifferentiaion process - __._% die by apoptosis
- occurs in c_____ of ovary
A
Folliculogenesis
- recruited primordial follicle grows + develops into a specialised graafian follicle with the potential to either ovulate its egg into the oviduct at mid-cycle to be fertilised or to die by atresia
- growth is by cell proliferation and the formation of follicular fluid
- development involves cytodifferentiation of all the cells and tissue of the follicle
- only a few follicles survive to complete the cytodifferentiaion process - 99.9% die by apoptosis
- occurs in cortex of ovary
*
12
Q
Growing Antral Follicle
- fluid filled spaces appear between the cells in the granulosa layers that coalesce into the antrum
0. 1µm⇒0.2mm⇒2-5mm
^25 days ^45 days
100x increase in granulosa cells
- early antral follicle - dependent on FSH for normal growth + sustained viability
A
Growing Antral Follicle
- fluid filled spaces appear between the cells in the granulosa layers that coalesce into the antrum
0. 1µm⇒0.2mm⇒2-5mm
^25 days ^45 days
100x increase in granulosa cells
- early antral follicle - dependent on FSH for normal growth + sustained viability
13
Q
What’s Happening at an Endocrine Level?
- Thecal cells produce large amounts of androstenedione, and small amounts of testosterone
- androgens converted to estradiol-17ß by the mural granulosa cells
- FSH stimulates proliferation of granulosa cells
- FSH induces expression of CYP19-aromatase needed for oestrogen synthesis
- mural granulosa cells produce increasing amounts of inhibin ß
- low levels of oestrogen + inhibin exert a negative feedback effect on FSH secretion = selection of the follicle with the most FSH responsive cells → dominant follicle
A
What’s Happening at an Endocrine Level?
- Thecal cells produce large amounts of androstenedione, and small amounts of testosterone
- androgens converted to estradiol-17ß by the mural granulosa cells
- FSH stimulates proliferation of granulosa cells
- FSH induces expression of CYP19-aromatase needed for oestrogen synthesis
- mural granulosa cells produce increasing amounts of inhibin ß
- low levels of oestrogen + inhibin exert a negative feedback effect on FSH secretion = selection of the follicle with the most FSH responsive cells → dominant follicle
14
Q
Ovulation
-
LH surge induces the release of inflammatory response cytokines and hydrolytic enzymes from the theca and granulosa cells
- leads to breakdown of the follicle wall, tunia albuginea and surface epithelium
- at the end, the antral cavity becomes continuous with the peritoneal cavity
- stalk-like attachment of the cumulus cells to the mural, granulosa cells detaches and the cumulus-oocyte complex becomes free-floating within the antral cavity
Paracrine Response:
- oocyte releases the transforming growth factor-ß (TGFß)
- stimulates the cumulus cells to secrete hyaluronic acid and other extracellular matrix components = enlargement of cumulus-oocyte comples, a process calledd cumulus expansion
A
Ovulation
-
LH surge induces the release of inflammatory response cytokines and hydrolytic enzymes from the theca and granulosa cells
- leads to breakdown of the follicle wall, tunia albuginea and surface epithelium
- at the end, the antral cavity becomes continuous with the peritoneal cavity
- stalk-like attachment of the cumulus cells to the mural, granulosa cells detaches and the cumulus-oocyte complex becomes free-floating within the antral cavity
-
Paracrine Response:
- oocyte releases the transforming growth factor-ß (TGFß)
- stimulates the cumulus cells to secrete hyaluronic acid and other extracellular matrix components = enlargement of cumulus-oocyte comples, a process calledd cumulus expansion
15
Q
Luteal Phase
- basal lamina of the mural granulosa cells is enzymatically degraded, and blood vessels + outer lying theca can push into the granulosa cells
- granulosa cells secrete angiogenic factos, such as vasculat endothelial growth factor (VEGF), angiopoietin-2 and basic fibroblast growth factor (bFGF) which increases blood supply to new corpus luteum
there is a change in the steroidogenic function of the theca and mural granulosa cells = luteinisation
A
Luteal Phase
- basal lamina of the mural granulosa cells is enzymatically degraded, and blood vessels + outer lying theca can push into the granulosa cells
- granulosa cells secrete angiogenic factos, such as vasculat endothelial growth factor (VEGF), angiopoietin-2 and basic fibroblast growth factor (bFGF) which increases blood supply to new corpus luteum
there is a change in the steroidogenic function of the theca and mural granulosa cells = luteinisation
