Uterus, Uterine tubes and Cervix (repro) Flashcards
1
Q
Changes in uterus and cervix
A
- maternal steroid increase size of new-born uterus
- grows with height during infancy
- myometrium dependent on estradiol
- corpus of uterus undergoes greater increase in size than cervix
2
Q
Myometrium
A
- outer muscular myometrium grows gradually throughout childhood
- increases rapidly in size and configuration during puberty
- changes in size through the cycle
- capable of vast expansion during pregnancy
- inner layer circular fibres
- middle layer figure of 8 or spiral figures
- outer layer longitudinal fibres
3
Q
Endometrium
A
- very thin in childhood
- begins to thicken at puberty
- dependant on steroids and responds cyclically to hormone changes
- oestrogen principally causes growth in proliferative phase
- can be seen and measured on an ultrasound scan
- good ‘bioassay; on oestradiol level (7-16mm)
- changes in glandular and epithelial cells through the cycle
- progesterone causes mainly differentiation in secondary phase
- at menstruation, stromal matrix with small columnar cells with glandular extensions 2-3mm thick glands are simple and straight
4
Q
Endometrial proliferative phase
A
- proliferative phase (follicular phase of ovary) following menses
- stimulated by oestrogen from the growing follicle
- stromal cell division
- ciliated surface
- glands expand and become tortuous
- increased vascularity
- neoangiogenesis maximal cell division by days 12-14
- when endometrium >4mm, induction of progesterone receptors and small muscular contractions of the myometrium
5
Q
Endometrial secretory phase
A
- secretory phase (luteal phase of ovary)
- 2-3 days after ovulation
- gradual rise in progesterone causes a reduction in cell division
- glands increase in tortuosity and distend
- secretion of glycoproteins and lipids commences
- Oedema, increased vascular permeability arterioles contract and grow tightly wound
- myometrial cells enlarge and movement is suppressed
- blood supply increases
6
Q
Regression of corpus luteum
A
- corpus luteum stimulated by LH from pituitary during luteal phase
- fertilised oocyte becomes a blastocyst and produces chorionic gonadotrophin (hCG)
- acts like LH ie on LH receptor and reduces the CL
- in absence of this, falling levels of steroid from CL results in menstruation
7
Q
Menstruation
A
- Prostaglandin release causes constriction of spiral arteriole
- Hypoxia causes necrosis
- proteolytic enzymes released from dying tissue
- outer layer of endometrium shed
- 50% lost in 24 hours, up to 80ml is considered normal
- bleeding normall lasts 4+ days
- basal layer remains and is then covered by extension of glandular epithelium
- oestrogen from follicle in next follicular phase starts cycle off again
8
Q
Uterine tube
A
Parts of the tube:
- Intramural (final part of tube, located at top of the uterus)
- Isthmus (part that connects ampulla and infundibulum to uterus)
- Ampulla (the first part of tube where. fertilisation occurs)
Mucosa: - secretory - columnar ciliated epithelial - non-ciliated peg Muscularis: - inner circular and outer longitudinal layers - blood vessels - lymphatics Serosa: - outer layer
9
Q
Changes in the cells lining the uterine tubes
A
- oocyte can only pass down the tube during mid-cycle
- cilia beat and secretory cells are active along with muscle layer contractions
- all response to oestrogen
- epithelial cells express high number of oestrogen receptors and undergo differentiation in response to oestradiol increase in height mid-cycle
- after a few days of exposure to progesterone, the oestrogen receptor are surpassed and oestrogen effects are overcome
- causes decrease in heigh mid-luteal onwards
10
Q
Fertilisation and early embryo development
A
- egg remains in tube for approx 5 days
- fertilisation occurs in ampulla
- damage to lining of tube by infection, endometriosis, surgery or adhesion can cause blockage or damage to ciliated epithelia
- results in pain, infertility and ectopic pregnancy
11
Q
Tubal patency
A
Laparoscopy and dye:
- a surgical procedure that looks at reproductive organs and helps determine why struggling to conceive, and whether fallopian tubes are blocked
Hystero Salpingo-contrast sonography (HyCoSy):
- a contrast enhanced fluoroscopic and flat plate study used to evaluate the endometrial cavity and fallopian tubes
12
Q
Cervix
A
- muscular structure capable of great expansion
- endocervical mucose is about 3mm thick
- lined with a single layer of columnar mucous cells, containing numerous tubular mucous glands which empty viscous alkaline mucus into lumen
- protective barrier to infection however it has to allow passage of motile sperm
- the ectocervix is covered with nonkeratinized stratified squamous epithelium
- this resembles the squamous epithelium lining in vagina
13
Q
Cervix during follicular phase
A
- Oestrogen in this phase causes change in vascularity of cervix and oedema
- mid-cycle oestrogen levels cause mucous to become less viscous
- this is a change in mucous composition
- mucus contains glycoproteins which become aligned and form microscopic channels
- sperm swim up the channels
14
Q
Cervix during luteal phase
A
progesterone in luteal phase causes: - reduced secretion and viscous mucous (reduced water content)
- glycoproteins now form mesh like structure (acts as a barrier to sperm and microorganisms)
- one mechanism of action of oral contraceptives
15
Q
Vagina
A
- thick walled tube approx 10cm
- lined by specialised squamous epithelial cells
- warm damp environment containing glycoprotein
suspectible to infection which is prevented by:
- layers of epithelial cells shed constantly and flow downwards with secretions
- secretions are from cervix and transudation from vaginal epithelium
- secretions change with cycle and are generally acidic providing anti-microbial protection
- Bartholins glands located slightly posterior to the left and right of the vagina and are homologous to bulbourethral glands in males
