Uterus, Uterine tubes and cervix Flashcards
In what region does the egg meet the sperm?
ampullary
How long does the embryo spend in the uterine tube?
5-6 days
What stage does the embryo need to be for it to be impanted into the uterus?
blastocyte
Where does the embryo implant?
endometrium (wall of the uterus)
What are the 3 layers of the uterus and the cervix?
- Endometrium is the mucosal lining of the uterus, it is shed every month
- Myometrium is the (smooth muscle fibres) muscular layer that makes up the body of the uterus
- Perimetrium surrounds uterus
What is the size of the myometrium dependent on?
oestrogen
What is nulliparous?
someone who has never given birth
What is parous?
someone who has given birth
How does the uterus size compare of a nulliparous and parous person?
nulliparous uterus is smaller bc high oestrogen exposure during pregnancy
What happens to the uterus size during menopause?
shrinks
Is uterus of a 4 year old bigger or a uterus of a new born baby?
newborn is larger bc in utero exposed to lots of maternal oestrogen
What are the 3 layers of the muscular (myometrium) layer of the uterus?
inner layer fibres = circular direction (IC)
middle layer fibres = spiral direction (MS)
outer layer fibres = longitudinal direction (OL)
What is the endometrial layer?
inner secretory layer of the uterus
After menstruation, what does the endometrium consist of?
stromal matrix layer
small columnar cells
What happens to the endometrium at the start (under oestrogen influence) of the menstrual cycle?
proliferation of the endometrium
What happens on the 2nd half of the menstrual cyle, when progesterone is dominating?
differentiation of endometrium
twisted blood vessels develop= increase SA for nutrients
glandular secretions
A week after ovulation, the endometrium reaches its max size. What is this?
10mm
What happens to the endometrium at the end of the menstrual cycle?
endometrium is lost
bc corpus luteum dies
so less progesterone
so endometrium cant be maintained
What are the 2 phases of the menstrual cycle called when talking about the ovary?
follicular and luteal phase
What are the 2 phases of the menstrual cycle called when talking about the uterus?
proliferative and the secretory phase of the uterus
What is the proliferative phase of the uterus influenced by?
endometrium under oestrogen influence
What is the secretory phase of the menstrual cycle under the influence of?
the secretory phase of the menstrual cycle is when the endometrium is undergoing development and differentiation under the influence of progesterone
What happens in the proliferative phase?
the stromal cells divide= form a ciliated surface
glands expand = become tortuous
increased vascularity
maximal cell division by day 12-14
the oestrogen levels keep increasing, until the negative feed back on the HPG turns into positive feedback, and there is an LH surge
What happens because of LH surge?
the egg gets ovulated
leaving the corpus luteum
NOW there is increased progesterone secretion, and the negative feed back is reinstated
What happens in the secretory phase?
cell division stops, endometrium differentiates glands become more tortuous glycoproteins and lipids secretions oedema myometrial cells enlarge blood supply increases
What happens to the egg during the secretory phase?
it gets fertilised and spends 5-6 days in the tube
If the embryo implants, the blastocyst released hCG. What does this do?
this is almost identical to LH
binds to the LH receptor on the corpus luteum
rescues the corpus luteum
corpus luteum keep producing produce progesterone
endometrial layer doesn’t break down.
What happens to the endometirum when progeterone is no longer released?
prostaglandidn is released in the endometrium
What does prostaglandin in the endometirum cause?
constriction of all extended spiral arterioles
hypoxia and necrosis in cells
vessels then dilate and there is bleeding
How many ml of blood is lost during menstruation?
80ml
What part of the endometrium remains when the endometrium sheds?
basal layer (Stromal layer)
What are the 3 parts of the uterine tube?
inramural, ampulary, isthmus
Describe the intramural portion.
uterine tube meets the uterus
very muscular and consists of a thick layer of inner circular and outer longitudinal muscles
many blood vessels
lymphatics
Describe the ampullary region.
where the fimbria are
where the tube meets the ovary
has big secretory mucosa layer
What are the cell types on the secretory mucosa?
secretory cell: this secretes growth factors, nutrients, adhesion molecules, cytokines etc (nutrients for early embryo)
columnar ciliated epithelial cell: these gently move the embryo towards the uterus (waft embryo)
What does the ampulla have that is a remnant of something?
ampulla also has something called the appendix vesiculosa-this is a remnant of the wolfian duct
How do oestrogen and progesterone act in the uterine tubes?
opposite to endometrium
oestrogen leads to differentiation and progesterone causes de-differentiation and anti-growth
How is the egg transpoted along the uterine tube?
cilia beat
muscular layer rapid contractions
Why does the cilia beat and why does peristalsis take place?
influenced by oestrogen
How can the uterine tube be damaged?
infection: chlamydia causes inflammation and blockage of the tube
endometriosis: the cells of the endometrium attach themselves in other places in the pelvis or the uterine tube−if they enter the uterus, they will continue to respond to estrogen and progesterone in a normal way, they will proliferate and differentiate and shed −this will cause an inflammatory response in the uterine tube
surgery
adhesions
these processes can lead to pain, fertility, and in some cases ectopic pregnancy
What is tubal patency test?
checks if the tube is blocked or not
What are tests to check for tubal patency?
laproscopy and dye
hysteron salpingo-contrast sonography (HyCoSy)
What is the cervix?
muscular structure
What is the endocervical mucosa and what does it do?
lines the cervix
single layer or columnar mucus cells
cels have lots of mucus glands= which empty viscous alkaline mucus into the lumen
this makes mucus plug
prevents infection, bacteria entering uterus
plug allows sperm to enter
How does oestrogen in the midcycle of follicular phase change the cervical mucus?
vascularity change
more fluid mucus
changes glycoprotein arrangement of mucus= form aligned channel
How does progesterone change the cervical mucus?
more viscous (because less water content) glycoproteins form mesh
What is the cervical canal?
between the external os and internal os
What is the structure of the cervial canal and what happens here?
striations and grooves
this area causes the sperm to get stuck here
it takes a while for the sperm to get past this stage
this forms a reservoir of sperm and thus there is constant release of sperm from the cervix
What is the vagina?
thick walled tube (10cm long)
warm damp
susceptible to infection
What glands are located in the vagina?
bartholin’s= secrete mucus to lubricate the vagina
What is the homologous to bartholin’s gland in males?
bulbourethral glands
In which layer of the uterus do fibroids grow and what are they responsive to?
It is the myometrium where uterine fibroids (benign smooth muscle tumours of the uterus) develop, they are responsive to oestrogen.
What are the layers of the uterine tube?
serosa= outermost layer
outer layer of smooth longitudinal fibres
inner layer of circular muscle fibres.= PERISTALSIS
How does laproscopy and dye work?
- A uterine cannula goes through the cervix and introduces a dye into the uterus
- A laproscope goes through the abdominal wall and you can look down it and see inside the pelvic cavity
- Can see the dye emerge out the end of the uterine tube (out the fimbrial end) this means there is no blockage. But if it doesn’t emerge it means there is something blocking it.
