Reproduction - female tract Flashcards
What attaches to the ovary?
- Broad ligament
- Utero-ovarian ligament
- suspensory ligament attaches to pelvic wall
Describe the structure of the ovary
- Covered by single layer of modified mesothelium
- tunica albuginea - poorly defined connective tissue
- stroma is divided into cortex and medulla
Cortex = Ovarian follicles, arranged in whorls/storiform pattern
Medulla = Loose fibroelastic tissue with blood vessels, lymphatics and nerves
Describe the stages of egg development in the ovary
- Primordial follicles - periphery of cortex (primary oocyte)
- Primary follicles - cyclic, oocyte forms and ZP forms around it
- Secondary follicles - antrum forms,
- Mature (Graafian) follicles - ovum surrounded by thick ZP
- theca interna, and theca externa (approx 400,000 at birth, only about 400 ever mature further) - Corpus luteum - secretes progesterone and oestrogen
(they either regress if pregnancy does not occur or grow)
What does the fallopian tube do? What are the 4 segments?
Runs throughout the length of the broad ligament
-Transports ovum to uterus (ampulla of fallopian tube, or uterine tube), this is where fertilisation occurs
4 segments
- Intramural - inside uterine wall
- Isthmus - 2-3cm thick wall
- Ampulla - expanded area
- Infundibulum - trumpet shaped opening to peritoneum, has FIMBRIAE
mucosa - has plicae folds, 3 cell types - secretory, ciliated and intercalated
- Muscularis (inner circular layer and outer longitudual)
- Serosa (connective tissue covered by mesothelium)
layers of the uterus
- Endometrium - glands proliferate during proliferative stage of menstral cycle
- Myometrium - thick muscular wall (inner longitudial, middle circular, outer longitudial)
- Serosa -
Describe layers of vagina
- Mucosa, non keratinising, strat squamous, elastic fibres, rich vascular supply
- Muscular wall (inner longitudial, middle circular, outer longitudial)
- Adventida
Lining of labia majora
Keratinising stratified squamous
Labia minora
Mostly non-keratinising stratified squamous
Describe the stages of oogenesis
metosis division and 2 meiotic
- In early development numerous mitotic divisions occur, stops around 7 months - divides into PRIMARY OOCYTE (diploid)
- first Meiotic division occurs in a featus up to prophase I - then it is in a state of meiotic arrest
- After puberty division produces first polar body and SECONDARY OOCYTE (possesses half chromosomes but all nutrients and cytoplasm)
- After ovulation and fertilisation the second meiotic division occurs in the fallopian tube - this produces OVUM (haploid) and secondary polar body
What is the role of granulosa cells?
Secretes estrogen
- small amounts of progesterone just before ovulation and INHIBIN
- Theca cells also synthesize estrogen
Why does the antrum form?
Due to fluid secretion of the granulosa cells
What does estrogen affect mucus?
Mucus is abundent, clear and water, this means that sperm can move through it more easily
-during ovulation
What does progestrogen affect mucus?
Mucus is thick and sticky
-This forms a ‘plug’ that prevents bacteria from entering forming protection if fertilization has occurred
(this is used as a form of contraception)
What causes menstruation?
The corpus luteum degenerates if fertilisation has not occurred, this means that there is a reduction in estrogen and progesterne - this is what causes menstruation
What occurs during menstruation?
a. Constriction of blood vessels
b. Reduction of Oxygen and nutrients
c. Entire layer except thin underlying layer
d. Smooth muscle undergoes rhythmic contractions
- these contractions are mediated by prostaglandins that are produced in response to low pro and est (can cause cramps, and affect other areas of the body = nausea, vomiting, headaches)
e. Blood vessels then dilate - causes hemorrhage and bleeding through the weakened capillaries
What are the follicular phase and luteal phase of menstrual cycle?
Follicular phase - development of follicle and secondary oocyte
-granulosa cells secrete esotrogen and small amounts of progesterone and inhibin
Luteal phase - after ovulation until corpus leuteum death
-corpus luteum secretes estrogen, progesterone, inhibin
Name the stages and changes of the uterine in the menstrual cycle
1. Day 1-5 - Menstrual phase endometrium degenerates 2. Day 5-15 - Proliferative phase endometrium begins to thicken and regenerate under the influence of estrogen, progesterone receptor synthesis also increases 3. Day 15 - Ovulation 4. Day 15-28 - Secretory phase endometrium secretes glucogen, followed by glycoproteins and mucopolysaccharides - progesterone (more hospitable environment) - also inhibits myometrial contractions (so implantation can occur) 5. Day 28-5 - Menstrual
What is the action of LH and FSH on cells of ovvum?
LH - acts on theca cells to synthesize androgens, these diffuse to granulosa cells
FSH - stimulates granulosa cells to convert androgens to estrogen
Describe the hormone patterns during the menstrual cycle
- FSH and LH slowly increase
- Antrals begin to grow and secrete estrogen
- Concs begin to rise
- One follicle becomes dominant and secretes large amounts of estrogen
- Large increase in estrogen
- FSH conc and secretion decrease, this causes atresia!
- Dominnant follicle enlarges due to fluid production and the antrum expands
- Granulosa cells form a mound that projects into antrum called CUMULUS OOPHORUS
- Primary oocyte completes first meiotic division
- Cumulus seperates from follicle wall so it floats in the antral fluid with oocyte
- Follicle becomes so large it balloons out of ovary surface
- Ovulation - the thin walls of ovary and follicle rupture at site that they are joined due to enzymatic digestion
- Secondary oocyte is carried out of ovary and onto ovarian surface by antral fluid
What occurs in hyperplasmia of the uterine body during pregnacy
Increase in number
What occurs in hypertrophy of the uterine body during pregnacy
increase in size - mainly menstruation
How does the increase in the size of the uterus occur during pregnancy?
As placenta develops, myometrium experiences burst of mitotic division, number of smooth muscle cells increases
-also due to hypertrophy of muscle cells, this is lost after delivery
After menstruation what layer is shred and which remains?
Most of endometrium leaving only BASES OF GLANDS and surrounding stroma - this is where the new endometrium is formed
What causes end of secretory phase and beginning of menstration?
Spiral arteries brefiely close, open again and leak blood into stroma - the temporary anoxia coupled with hydraulic pressure of blood disrupts the stroma causing the decidua to detach and menses to begin
What causes low Ph of vagina
- Surface cells accumulate glycogen and flask off
2. Bacteria feed on glycogen generating lactic acid = low ph detering pathogens
Where does fertilisation occur?
Ampulla of uterine tube/fallopian tube
etopic ferti at uterine tube
Describe follicular development
- Cortex of ovary contains many germ cells - dormant primordial follicles consisting of a germ cell enclosed in theca derived from stromal cells (theca = single layer of squamous cells)
- Theca becomes cubodial or columnar
- Differentiates into inner granulosa cells - begin to secrete oestrogen and outer flattened cells, and follicle becomes secondary follicle - germ cell also devlops a prominent zona pellucida that separates it from the theca
- further growth and development of theca = results in development of mature Graafian follicle - antrum has also formed and oocyte is attached to perophery by stalk of granulosa cells known as cumulus oophorus
(mainly follicles that start to differentiate fail to develop fully and perish) - Oocyte is released from graafian follicle at ovulation, theca persists and becomes corpus luteum (secretes oestrogen and progesterone)
