oogenesis, the female tract and endocrine control (2) Flashcards Preview

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Flashcards in oogenesis, the female tract and endocrine control (2) Deck (22):
1

uterus

- muscular organ
- 7.5cm long and pear shape
- luminal volume ~10mls
-pregnant uterus contains ~5L of baby, amniotic fluid and placenta
- growth partially under the control of estrogen
- growth due to stretching of existing cells rather than proliferation

2

uterus position

normally anteverted
- top faces forwards

25% of women have a retroverted uterus (no effect on pregnancy)

3

uterus structure

top = fundus
bottom = cervix (projects into vagina)

3 main layers:
- 1. serosa (perimetrium)
- 2. muscular myometrium
- 3. inner endometrium

4

myometrium

- 90% of uterine tissue
- allows expulsion of fetus
- no effected by menstrual cycle
- 10mm thick

5

structures within endometrium and changes during menstruation

basilar layer = retained during menstruation

functional layer = lost during menstruation

uterine glands = lost during menstruation

simple columnar epithelium = lost during menstruation

6

decidua

name given to endometrium during pregnancy

tissue which dissociates from the uterus when the placenta is delivered

where the human embryo implants

endometrium become decidualized during each menstrual cycle

7

phases of uterine cycle

menses

proliferative phase

secretory phase

8

phases of the ovarian cycle

follicular phase

luteal phase

9

decidual reaction

fibroblasts in the stroma of the uterus (endometrium) become oedematous and lay down glycogen for the embryo to eat

cells change from long spindle cells to large polygonal cells

occurs spontaneously each menstrual cycle

10

uterine blood supply

uterine artery --> radial artery --> arcuate arteries --> radial arteries --> spiral artery (only arteries in endometrium = gets shred)

11

blood supply during pregnancy

mums blood gets to the placenta via the spiral arteries

12

blood supply and menstruation

the spiral artery terminal segments are lost along with the rest of the functionalis layer of the endometrium

- to prevent excessive blood loss these arteries undergo spasm

13

relationship between cycle length and age

average cycle length decreases as age increases

- cycle lenghts shorten from 30 days in females aged 18 to 28 days in women aged 42 (AVERAGE)

14

follicular vs luteal phase

follicular/proliferative phase is longer and more variable in length than the luteal/secretory phase

15

importance in dating the endometrium

implantation occurs around 7 days post ovulation therefore can assist fertility

- commonly done through ultrasound (measuring thickness) or biopsy

16

features of early luteal

- tortuous glands

- basal vaculotation

-glandular secretions

17

estrogen stimulates

- epithelial and stromal cell proliferation

- stromal odema

- glandular secretions (serous)

- synthesis of intracellular progesterone receptors (estrogen priming)

- myometrial activity

18

progesterone stimulates

- glandular secretions in luteal phase (against an estrogen background)

- stromal cell differentiation

19

progesterone inhibits

myometrial activity (smooth muscle relaxant)

20

ectopic implantation

- can occur anywhere in the abdominal cavity

- most common inside the fallopian tubes

21

endometriosis

endometrial tissue outside of the uterus often on the ovaries

- associated with infertility
- causes chronic pain

22

zones of the cervix and epithelium

endocervix = columnar

transformation = squamous (HPV infects here and can lead to cervical cancer)

ectocervix = stratified squamous