ILO WEEK 5 Flashcards
Summarise the development, structure and functions of a normal placenta in a healthy pregnancy
Differentiation of trophoblast:
- the proliferating inner villous cytotrophoblast
- non-dividing outer multinucleate layer called the syncytiotrophoblast
- Lacunae begin to develop within the STB mass; blood from spiral arteries will fill the spaces
- Initially maternal blood escaping from the spiral arteries passes into lacunae before the mouths of the spiral arteries become blocked with EXTRAVILLOUS TROPHOBLAST CELLS that form intra-arterial plugs; secretions from uterine glands keep it alive
VILLOUS TREE;
Cytotrophoblast cells migrate, forming villous projections that extend towards the maternal basal plate
By 3rd week of gestation tertiary villi have formed consisting of an outer monolayer of syncytiotrophoblast, invaded by an inner layer if cytotrophoblast cells and vascularised with foetal capillaries
Define the terms pre-eclampsia
Hypertension occurring (typically) after 20 weeks with associated oedema and proteinuria ( different with existing hypertension) Affects up to 6% of UK pregnancies
Give a brief explanation of the implications of these disorders in pregnancy (preeclampsia, eclampsia, foetal growth restriction)
They may lead to risk of life of both mother and child; eclampsia (seizures)
Preterm birth, stillbirth etc.
Is there more?!
Describe the pathophysiological mechanism s that underlie pre-eclampsia
Pre-eclampsia defined as: new onset hypertension (systolic >140 diastolic >90 mmHg) occurring after 20 weeks’ gestation with new proteinuria (protein:creatine ration >30mg/mmol)
- Abnormal placentation
- Abnormal maternal response to placental trigger
- Organ/systems failure
ENDOTHELIAL DYSFUNCTION CENTRAL
an imbalance between vasodilator and vasoconstrictor molecules produced by or acting on the endothelium
Many atypical presentations of PE; women with preexisting renal disease and/or hypertension = diagnosis challenging
Left untreated may progress to eclampsia, a life treating condition characterised by convulsions
Factors:
genes, the placenta, immune response, maternal vascular disease
Much of morbidity due to high rates if intervention an iatrogenic preterm delivery indicated as risk of severe maternal complications and still birth
Understand current guidelines for the management of pre-eclampsia
Reducing the risk of hypertensive disorders before and during pregnancy
Change lifestyle factors
PIGF Based testing
Define the term fetal growth restriction
Failure of the foetus to reach its genetically predetermined growth potential
Results in birthweight below 5th centile of individualised birthweight ration (IBR) charts (12 week scan; try to use ulrasound to establish; then with next scan see if growth restricted)
Affects 5-10% of pregnancies
May be associated with abnormal umbilical artery blood flow on Doppler ultrasound and/or oligohydramnios (lack of amniotic fluid)
Can also be associated with pre-eclampsia and other complications of pregnancy (e.g diabetes)
Major risk factor for stillbirth, survivors are at increased risk of neonatal and adulthood diseases
Define the term preterm birth
Delivery at <37 weeks gestation
Extremely preterm <28 weeks, very preterm 28-32 weeks, moderate to late preterm 32-37 weeks
Clinical features of pre-eclampsia
Multi-system maternal syndrome, unique to humans
Implications of the for research? very challenging; do not understand pathogenesis
Notoriously heterogenous presentation
- Hypertension
- Proteinuria
- Oedema- hands, feet, face
Consequence of endothelial dysfunction
Severe pre-eclampsia can cause:
- Headaches
- Blurred/ flashing vision
- Pain in upper right abdomen
- Nausea/ vomiting
- Heartburn that does not go away with antacids
- Rapid oedema
Permigrividae
1st pregnancy/ first with new partner/ first pregnancy in 10 years
Concretions
Commonly found in prostate
List and recognise the major histological tissue types of the ovary.
Superficial - deep
Capsule
- Germinal Epithelium, a cuboidal epithelium
- Tunica Albuginea, a connective tissue.
Cortex, the outer region of follicle development.
Of the mature (graafian) follicle - theca interna/ externa.
- antrum
- liquor folliculi
- follicle cells
- oocyte
- zone pelucida
- cumulus oophorus
- corona radiata
- corpus luteum after ovulation is another key structure.
List and recognise the major histological tissue types of the uterus.
Know the difference between proliferative, secretory and menstrual histology of the uterus.
Key hormones are: LH and FSH.
Essentially focuses around two layers; the myometrium (smooth muscle) and the internal endometrium (itself made up of three layers: strata compactum, spongiosum (functionalists), basalis.
- Proliferative Stage
Modulated by FSH.
The endometrium thickens and the Stratum Functionaliks forms from the Stratum Spongiosum, served by hastily built spiral arteries.
- Secretory Phase
Modulated by LH.
Glycogen rich secretions. Cork screw shaped glands. Less staining due to open spaces.
- Menstrual Phase (menses)
Modulated by decreasing LH as the Corpus Luteum deteriorates.
Spiral arterioles contract, and the Stratum functionalists becomes ischaemic. Becomes necrotic, and the arteries rupture producing menstruation.
Provide a brief overview of the cell types found in the female reproduction tract.
Uterine tubes:
Ciliates columnar cells, secretory cells.
Uterus:
Simple columnar epithelium.
Vagina:
Non-keratinised squamous epithelium.
Describe the structure and function of:
Theca Cells
Granulosa Cells
Germ Cells
- Theca Cells
- work with granulosa cells. Produce oestrogens and androgens in the maturing follicle - Granulosa (follicular cells) Cells
- supportive. Produces oestrogen. - Germ Cells
- produces the gamete. Surrounded by zone pelucida and corona radiata.
Describe the peritoneal relationships of the reproductive organs in both sexes
FEMALE:
Uterus -> peritoneum covers it
Ovaries covered in layer of peritoneum forming a ligament
Fallopian tubes also enclosed in peritoneum
BUT COULDNT FIND NICE INFO!!!
MALE:
Peritoneum surrounds scrotum bladder and prostate but not the penis itself
Contents of the spermatic cord
Vas deferens. Testicular artery. Artery of the ductus deferens. Cremasteric artery. Pampiniform plexus. Genital branch of the genitofemoral nerve. Parasympathetic and sympathetic nerves. Lymphatic vessels.
The skeleton of the penis
I think it refers to the structures in the penis: corpus cavernosum (2) and corpus spongiosum (1) ???
ligamentous pelvis and inguinal ligament attachments
???
clinical relevance of pelvic imaging
???
histological features of the male reproductive tract and the kidney
???
Contraceptive pills (mechanism of action)
Combined pill (oestrogen + progestins) - Prevents the ovaries from releasing the oocyte, they also thicken the cervical mucus and - endometrial lining to prevent the sperm from reaching the egg This happens because progesterone and oestrogen have a negative feedback mechanism on the pituitary gland, thus reducing the pulsatile frequency of the gonadotropin release (LH& FSH) from the anterior pituitary. The lack of the LH surge mid-cycle prevents the release of the oocyte.
Mini pill (continous progestin)
- need to take everyday at the same time
- it thickens the mucus in the cervix, preventing the sperm from reaching the egg. Sometimes it
may also prevent ovulation (not always)
The process of gametogenesis in female
From one primary oocyte we only get one mature egg; the rest becomes polar bodies that support and nurture the egg
In fetal development the process is arrested at the meiosis I prophase (still diploid)
After big spurge of FSH in puberty process restarts (one egg at a time)
primordial follicle ->
a cluster of primary oocytes with a single layer of cells
primary follicle ->
- (granulosa cells present; theca cell develop Kit Ligand)
- Zona pellucida present
- Production of androgens begins
secondary follicle ->
-propper blood supply
- fluid-filled antrum
- granulosa cells develop hormone receptors
- aromatase
- oestradiol from granulosa cells inhibits secretion of FSH and LH (but stimulates the production
- inhibin stops the release of FSH
Tertiary (Graafan) follicle -> on the point of release
- corona radiata develops
- positive feedback to oestrogen develops
LH released in massive proportion -> ovulation
Then CORPUS LUTEUM -> progesteron
Corpus ALBICANS -> degeneration
If any of the other follicles develop as well -> undergo death -> ATRESIA
Contraceptive pills (mechanism of action)
Combined pill (oestrogen + progestins) - Prevents the ovaries from releasing the oocyte, they also thicken the cervical mucus and - endometrial lining to prevent the sperm from reaching the egg This happens because progesterone and oestrogen have a negative feedback mechanism on the pituitary gland, thus reducing the pulsatile frequency of the gonadotropin release (LH& FSH) from the anterior pituitary. The lack of the LH surge mid-cycle prevents the release of the oocyte.
Mini pill (continuous progestin)
- need to take every day at the same time
- it thickens the mucus in the cervix, preventing the sperm from reaching the egg. Sometimes it
may also prevent ovulation (not always)
Development and regression of the kidney
Develops from intermediate mesoderm
3 structures -> pronephros (cervical region)
-> mesonephros (abdominal region)
-> metanephros (pelvic region)
Metanephros forms the definitive kidney (together with ureteric bud -> mesonephric duct)
Others form then regress; rudimentary
Becomes functional in week 11
