Female Reprodutive System Flashcards
Why does the uterus change
Provide support for the growing fetus
Expel fetus and placenta in labour
Contract after birth to prevent maternal haemorrhage
Remodel by involution to the non pregnant Tagus within 4 eels of birth
What does the uterus grow due to
Increased calculation and fluid retention in the mayo metric M under influence of progesterone nd oestrogen an mechanical stretching
What does the uterus change to and from
Pelvic organ to abnormal organ almost reaching the border of the liver by full term
What are the layers of the uterus
Inner. Endometrium - ciliates epithelium
Middle - myometrium- thick muscle cells
Outer - perimetrium - loose connective tissue protecting uterus room friction with other organs
What does the endometrium become
Decidua
What is the process of decidualization
Cells differentiate to prepare for implantation, protect from the trophoblast and repae to provide nutrition to th blastocyst
Endometrial thickness of 8mm or more is necessary for successful implantation
What are the three layers of the myometrium
Longitudinal
Oblique
Circular
Hyperplasia - myometrium
10x increase in number of myocytes in first half of pregnancy
Hypertrophy
Increase in size of myocytes in second half of pregnancy
What does hyperplasia and hypertrophy result in
Myometrium growth during pregnancy
Uterine contractions - myometrium
High levels of progesterone in pregnancy promotes relaxation of myometrium and inhibit production of prostaglandins and oxytocin receptors (inhibits contractions)
T the end of the pregnancy, rise in oestrogen and CCRH trigger activation of xytocin receptors and prostaglandins needed for regular contractions
In established labour, oestrogen, oxytocin and prostaglandins increase the density and permeability of the gap junctions between the myometrial cells so contraction beck more coordinated and forceful.
Cessation of bleeding
In the middle oblique muscle layer, each myocytes is a figure or 8 to enable it to constrict around a blood vessel t stop bleeding post birth.
What is the perimetrium
B-road ligaments or med by the perimetrium open out to accommodate massive increase in size of uterine and ovarian blood vessels, lymphatics and nerves
Enlarge uterine nerves act as a reservoir for blood during uterine contractions
What is the ishmus
The lower uterine segment is formed from the isthmus which does not undergo such hyertrophy and becomes increasily thin and distensible. The muscle fibre are mostly transverse
Lowe segment caesarean section where the uterine in ion follows the direction of the muscle fibres - less vascular- reduce blood loss
How does the blood flow to the uterus change
There is.Ten fold increase from 2% cardia output in the non pregnant state to 17% at term
Uterine and ovarian arteries hypertrophy muscle cells increase in size) greatly in pregnancy.
The blood is redistributed within the uterus and a pregnancy progresses 80-0% goes to the placenta and the remainder is equally distributed between the myometrium and the endometrium
What is uterine vascular remodelling
Blood vessels within the uterus change significantly during pregnancy
What are arteries like pre preganancy
Spiral arteries supply bloood to the endometrium in the menstrual cycle and are narrow in diameter
What are the spiral arteries like in pregnancy
Trophoblast causes them to dilate 5-10 x and lose muscle from their walls
The arteries straighten out and increase in diameter so by 2nd trimester maternal blood pools into the intervillous space - pool of maternal blood used for gases exchange between fetus and woman.
The intervillous space will contain 400-500ml oxygen rich blood
How ones the uterus chang postnatally
Following birth, the uterus returns to its normal size, tone and position through the process of involutin
Through this process the uterus reverts back to being a pelvic organ from occupying te abdomen
At the end of the first week postnatally the uterus has lost 50% of its muscle bulk
By the end of the sixth week, the uterus should be at me pre pregnant position of anteversion nd anteflexion - normal/.
What ae the three processes that enable myometrium to return to normal thickness
Ischaemia
Autolysis
Phagocytosis
Ichaemia
Muscle of the uterus retract at te end of 3rd stage of labour to constrict blood vessels at the placental site
Resulting in haemostasis
Uterine blood supply is greatly reduced
Autolysis
Th process of removal of the redundant actin and myosin muscl fibres and cytoplasm by proteolytic and macrophages. The size of the individual myometrial cells is reduced
Phagocytosis
Removes the excess fibrous and elastic tissue
process is incomplete and some elastic tissue emails so that a uterus never quite returns to the nulliparous state
On what days do the lochia change
The superficial layers of the Dudu are shed as bleeding per vaginum with regeneration off the endometrium
Lochia
Rubra - 1-3 days
Serosa - 4-10 days
Alba - 11-21 days
What happens to the wall of the cervix
Decreases until reared 0.4 cm at term
What is the cervix transformed to
Under normal control, transformed from closed rigid non distensible, collagen dense structure to a soft distensible and nearly indistinguishable ring of tissue capable of stretching and dilating to permit the passage of a fetus at term
What happens as the cervix remodels
The tissue softens ad causes collagen scaffold to become disorganised and unstable
What is softening of cervix
Occurs soon after conception as the collagen fibres are disrupted
Cervical odeoma
Increased vascularity causes bluish tint
What is ripening of cervix
Can precede onset of labour by several weeks
Cervix loses its structure and becomes soft thin and pliable
What is effacement and dilation
Muscle fibres pulled up t become part of the lower uterine segment, the length of the cervix shortend - effacements. The external os opens - dilation
What is cervi xrepair
Going back to pre pregnant state
Not identical
What is operculum
Columnar epithelial cells of the cervix undergo profileration and secrete mucus that acts as a plug
It provides a protective seal against the entry of pathogens and also has antibacterial properties
Late in the cervical softening phase and before or during early labour the cervical canal may dilate by up to 3cm and the operculum s released as a blood tinged discharge known as show
What is the bishop score
Pre labour cervical scoring system 0-13
To predict likelihood of spontaneous labour or cervical faourability
Higher the score the higher chance of labour/ success of induction
How does the vaginal walls change
The epithelial mucosa thickens
Connective tissue loosens and smooth muscle cells hypertrophy - increase in size
What changes about cervical secretions
Increased during pregnancy to form a thick white discharge - leucorrhea
Wat happens to vaginal ph
It remains low <4.5 which inhibit s growth of pathological vulvo- vaginal organisms particularly through 2nd and 3 rd trimester
What happens to the blood flow and vessels in perineum and Vila
Increased vascularity and hyperaemia - blood flow in the skin and muscles of the pperineum and vulva
Vulvar varicosites
Varicose veins in the Vulcan caused by vasodilation and reduced venous tone
Usually resolve following pregnancy. And do not effect mode of birth
Contraception without synthetic hormones
Lactational amenorrhea
Fertility awareness - family planning
Condoms
Intrauterine device - copper coil
Lactational amenorrhea
Suitable if you are exclusive breastfeeding and baby is less than 6 months and if havent had menstrual period
98% effective
High levels of prolactinstps the release of the gonadotropin releasing hormone (GnRH) from the hypothalamus and luteinizing hormoe (LH) from the pituitary gland
The luteinizing hormone sure is preened thus preventing ovulation
Cautions of Lactational amenorrhea
If breastfeeding frequency is reduced, fertility may return before next menstrual period
Expressing breastmilk rather than breastfeeding increases chance of pregnancy
Scheduledor restricted breastfeeding increases chance of pregnancy
Fertility awareness
Predicting ovulation through daily monitoring of temperature and cervical fluid monitoring and menstrual tracking
Avoids penetrative sex on fertile days - including das when sperm may survive and egg may survive (8-9 days per month)
Efficacy wh perfect use 91-99% but as low as 75% with typical use
Efficacy of apps is highly variable and nt well trialled
Condoms
Non hormonal form of barrier contraception
Male condoms worn on penis
Femal =e condoms worn inside vagina
Protect against STIs
When used correctly 98% effective
Some use latex which can be an allergy
Oil lube can degrade condoms
Copper coil
Safe for breastfeeding
Copper acts as spermicide
Copper increases levels of copper ions - prostagladins and white blood cells within the uterine and tubal fluids. It alters the cervix mucus which makes it ore difficult fr sperm to reach an egg and survive
It can also stop a fertilised egg from being able to implant itself
Lasts 5-10 years
More than 99%effctive
What do progestogen based contraceptives do
Progestogen is a synthetic versiion of progesterone
It thickens the cervical mucus which makes it difficult for sperm to move through cervix and thins the endometrium o an egg is less likely to able to implant itself
It can also prevent ovulation
Intrauterine system - IUS
Small t shaped device inserted through cervix
Insertion ad removal may be painful and pain relief may be used
Reese’s progestogen into uterus - local suppressive effect on endometrium with lower plasma level than when taking oral pill
Progestogen implant in arm
Suitable from 4weeks post birth
Lass three years
More than 9% effective
Fertility returns to normal immediately after removal \small procedure
Side effects - mood swings headaches
Progestogen depo injection
Intramuscular injection
Perfect use - >99% effective but with typical 94%
Provides contraceptive effects for 8-13 weeks
Su\uitable from 6 weeks post birth
Side effects - changes. To menstrual cycle weight gain headaches
Fertility make take up to a year to return
Progestogen only pill
The traditional pillPrevents pregnancy by thickening the mucus in the cervix to stop sperm reaching an egg - takes 2 days - has to be taken within 3 ours of the same time each day
The desogestrel pill also stood vulation - takes 7 days - must be taken within th e12hours of the same time each day
if taken perfectly more than 99% effective if not only 91 % effective
2 types of pill
Can start pill 21 days post birth
Suitable whilst breastfeeding
How do combined oestrogen and progestogen contraceptives work
Suppress mid cycle surge of LH and FSH and thereby inhibiting ovulation
Combined pill
Contains oestrogen and progestogen
Taken correctly - more than 99% effective
Typical use - 91% effective
Oestrogen increases risk of venous thromboembolism (VTE) so not suitable for raised BMI smoker or history of VTE
Side effects. Breast tenderness, headaches and nausea
Not suitable for first 6 weeks of breastfeeding caution use as oestrogen may affect supply
Combined patch
Contains oestrogen and progestogen like the combined pill - same mechanism for preventing pregnancy
Same risk of VTE associated with oestrogen based contraceptives
Change patch every 7ths for 3 weeks then have 1 week patch free
Temporary side effect headaches nausea breas tenderness ad mood changes
