5- Uterine tubes, Uterus and Cervix

Question 1

how do hormone changes of the menstrual cycle affect the structure of the uterine tube?

Answer 1

menstrual cycle divided into two phases - the follicular and literal phases

oestrogen dominates the follicular phase - makes uterine cells differentiate for the perfect environment for fertilisation
- ciliates epithelial cells with cilia waving = have many oestrogen receptors, respond to oestrogen
- secretory cells secreting nutrients

luteal phase is dominated by progesterone
- conditions are maintained for a few days for fertilisation before progesterone begins de differentiating cells
- uterine tube becomes a hostile environment for pregnancy

Question 2

what changes occur during the endometrial proliferation phase

Answer 2

endometrium grows
stromal cell division
glands expand and twist
increased vascularity and neoangiogenesis

Question 3

what changes occur during the endometrial secretory phase

Answer 3

increased growth of spiral arteries
secretory glands develop - become more tortuous, secrete nutrients, growth factors, glycoproteins and lipids
uterus lining becomes receptive for implantation through changes in glandular and epithelial cells

Question 4

define endometriosis

Answer 4

when tissue similar to the uterus lining grows outside the uterus

Question 5

how does endometriosis affect health?

Answer 5

cells of endometrial lining are still receptive to hormones such as oestrogen and progesterone

proliferation of the lining during the first half of the menstrual cycle, differentiate and become secretory during the second half. disintegrates and bleeds once the corpus luteum dies

this can cause pain, inflammation, blockages of the uterine tube

also affects fertility, can result in ectopic pregnancy

Question 6

how is endometriosis assessed?

Answer 6

through a visual inspection

no blood tests

Question 7

describe two methods for investigating problems with the uterine tubes

Answer 7

laparoscopy and dye
- blue dye inserted by a cannula into the cervix, travels to the uterus and tubes
- if the uterine tubes are patent the fibre optic camera will see the blue dye come out
- fibre optic camera inserted through an incision in the abdomen

HyCoSy
- ultrasound opaque dye inserted into cervix using a catheter
- ultrasound probe on the surface of the skin can follow the dye = assess latency of uterine tubes

Question 8

under what circumstances would a laparoscopy with dye be more preferable than a HyCoSy procedure?

Answer 8

• allergies to the dye
• lesions outside the uterus = HyCoSy will only tell you if the tubes are blocked

Question 9

functional structure/anatomy of the uterine tube

Answer 9

three sections - intramural, isthmus and ampullary

intramural = thickest/ lots of muscle, little mucosa, closest to uterus

isthmus = thick muscle layer, some mucosa

ampullary
- thin muscle layer = inner circular layers, outer longitudinal layers
- highly convoluted secretory mucosa = increase SA for secretions

Question 10

describe the three types of mucosal cells

Answer 10

secretory cells = allow two-way communication between embryo and uterine tube environment

columnar ciliated epithelial cells = activated during endometrium proliferative phase, cilia wave embryo down uterine tube

non-ciliated ‘peg’ cells = immature secretory or ciliated cells? function unsure.

Question 11

what is serosa?

Answer 11

outer layer of the uterine tube

Question 12

how can the corpus luteum be saved?

Answer 12

a fertilised embryo will produce hCG - has the same alpha subunit as LH and can bind to LH receptors on the corpus luteum to save it

corpus luteum can be maintained to produce high levels of progesterone throughout pregnancy

causes the endometrial secretory phase and prepare the endometrium for implantation

Question 13

describe the mechanism for the shedding of the endometrium during menstruation

Answer 13

prostaglandin release causes spiral arteriole constriction - endometrial tissue becomes ischaemic, induces hypoxia and thus tissue necrosis

tissue dies by necrosis - releases proteolytic enzymes

vessels then dilate and bleeding ensures

outer layer of the endometrium is shed until basal 2-3mm thick layer is left, and then covered by extension of the glandular epithelium

Question 14

what substances are exchanged between the embryo and uterine tube?

Answer 14

growth factors
cytokines
messengers for development

Question 15

describe changes in the cervix during the follicular phase

Answer 15

cervical mucus under high oestrogen influence

• increases blood flow to cervix = increases oedema = increases water content of cervical mucus
• cervical mucus glycoproteins cross-link to form microscopic channels for sperm to swim through, less viscous

Question 16

describe changes in the cervix during the luteal phase

Answer 16

high progesterone - undoes oestrogen effects
- reduces water content and viscosity of mucus
- glycoprotein mesh cross-links to prevent sperm getting in

Question 17

how is the vagina protected against infection?

Answer 17

• layers of epithelial cells constant shed and flow downwards
• secretions from the cervix change with cycle = generally acidic and thus antibacterial

Question 18

function of Bartholin glands in the vagina

Answer 18

secrete mucus to lubricate the vagina