What is the most common position for the uterus to be found in?
Anteverted and anteroflexed (although retroverted and retroflexed is a normal and common variant)
Describe the gross histology of the ovary.
Medulla - forms the core. Made of loose connective tissue, arteries, veins, lymphatics and is continuous with the hilum (and therefore, broad ligament)
Cortex - scattered ovarian follicles in a highly cellular connective tissue stroma.
The outer layer (tunica albuginea) is covered by a single layer of cuboidal cells (the germinal epithelium).
Describe the histology of the vagina.
- non-keratinised stratified squamous epithelium; this contains glycogen, which is metabolised by commensals to prevent overgrowth of pathogenic bacteria
- lamina propria (elastic fibres, thin blood vessels)
- fibromuscular layer (inner circular, outer longitudinal)
Name the stages in and after folliculogenesis.
- primary follicle
- secondary follicle (contains an antrum filled with liquour folliculi)
- follicle approaching maturity
- Graafian follicle [-> ovulation]
- corpus haemorrhagicum
- corpus luteum
- corpus albicans
Describe the location and function of theca and granulosa cells, and their relation to the sex hormones.
- theca (formed from surrounding stromal cells, therefore forming outer layer): converts cholesterol to androstenedione by desmolase. by LH
- granulosa (inner): converts androstenedione to oestrogen by aromatase. by FSH
Describe the gross histology of the uterus.
Two layers: the reserve stratum basalis (containing straight arteries), and the stratum functionalis (sheds, contains spiral arteries)
- prostaglandins cause spiral arteries to constrict, causing hypoxia and sloughing of the SF
What is the broad ligament?
A double layer of peritoneum containing the uterine tubes and proximal part of the round ligament. It helps maintain the uterus in the correct midline position.
What is the round ligament?
The embryological remnant of the gubernaculum. It attaches to the lateral uterus (and therefore its proximal part is within the broad ligament) and passes through the deep inguinal ring to the superficial perineum.
What is the mons pubis?
The area anterior of the vagina, containing highly oblique hair follicles, overlying a subcutaneous fat pad and the pubic symphysis.
What are the labia majora and minora?
- majora: extensions of the mons pubis, rich in apocrine and sebaceous glands
- minora: thin skin folds lacking s/c fat and hair follicles, but rich in vasculature and sebaceous glands
Describe the rough borders of the breast.
- extends from ribs 2-6
- extends from the lateral border of the sternum to the midaxillary line
- lies superficial to the pectoralis major and serratus anterior
What is the main function of the retromammary space?
Allows relative mobility of the breast to the underlying muscle.
Describe the lymphatic drainage of the breast.
- 75% to axillary nodes (removal in e.g. breast cancer can cause upper limb lymphoedema)
- medial quadrants: parasternal nodes
- upper quadrants: deltopectoral, supraclavicular nodes
What is the arterial supply of the breast?
internal thoracic (internal mammary), axillary (thoracoacromial)
Which structures contribute to urinary and faecal continence?
- urinary: external urethral sphincter, compressor urethrae, levator ani
- faecal: puborectalis (bends anorectum anteriorly)
Describe the ‘corners’ of the urogenital and anorectal triangles.
- pubic symphysis
- ischial spines x2
Name the layers of the pelvic floor.
- pelvic diaphragm
- deep perineal pouch
- perineal membrane
- superficial perineal pouch
Name the muscles (and their innervation) of the pelvic diaphragm, the deepest layer of the pelvic floor.
- levator ani (puborectalis, pubococcygeus, iliococcygeus)
- supplied by pudendal nerve, and nerve to levator ani
Name the contents of the superficial perineal pouch, the most superficial layer of the pelvic floor.
- erectile tissue, corpus cavernosum, root of penis, bulb of vestibules
- ischiocavernosus, bulbocavernosus, transverse perineal
- perineal body (‘central tendon’)
- proximal spongy urethra
- Bartholin’s glands (‘greater vestibular gland’)
Describe the first step in embryological development of the reproductive system.
wk4 -> intermediate mesoderm forms the urogenital ridges on each side of the primitive aorta
- this forms the genital ridge (more medial) and urinary system (laterally)
Describe the development of the female genital system.
- occurs in absence of SRY
- paramesonephric duct in three parts: cranial, horizontal, and caudal
- vaginal lumen created by vacuolisation of the Mullerian tubercle (connecting point of the two paramesonephric ducts)
Describe the development of the male genital system.
- primary sex cords form testis/medullary cords which engulf the PGCs, forming spermatogonia
- Sertoli cells secrete anti-Mullerian hormone
- AMH -> degeneration of PMN, development of Leydig cells -> testosterone -> DHT
- Accessory glands develop wk 10
Describe the hormone changes observed through the menstrual cycle.
- menstrual: inc FSH, dec oestrogen & progesterone
- preovulatory: inc. oestrogen
- ovulatory: inc. oestrogen -> inc. LH -> inc. progesterone
- postovulatory: inc. LH, dec. FSH. inc. progesterone and oestrogen if fertilisation occurs, dec. if not (+inc FSH)
Define the normal menstrual cycle length, and the terms oligomenorrhoea and amenorrhoea.
- normal: 24-38 days (e.g., +/- 4 days)
- oligomenorrhoea: cycle lasts >35 days
- amenorrhoea: no menstruation (may be primary or secondary)
Name the two main ligaments of the pelvis, their attachment points, and the foramena they form.
- sacrospinous (sacrum to iliac spine)
- sacrotuberous (sacrum to ischial tuberosity)
- greater and lesser sciatic foramen
Describe the arterial supply of the pelvis.
- common iliac supplies internal and external iliac arteries
- internal iliac gives anterior and posterior branches
- posterior branch: lateral sacral, superior gluteal
- anterior branch: gives off umbilical (superior vesicle, artery to vas deferens)
- – obturator, inferior vesicle, uterine, vaginal
- – continues as internal pudendal, which gives inferior rectal, perineal, posterior labial/scrotal, art. of bulb of vestibule/bulb of penis, urethral, deep art. of penis/clitoris, dorsal art. of penis/clitoris
Name the two main arterial supplies to the pelvis that do not arise from the common iliac artery.
- gonadal: L2 aorta (testicular / ovarian if sex of patient is known)
- superior rectal: continuation of inferior mesenteric
Name the key bony landmarks associated with the ilium, ischium, and pubis.
- ilium: iliac crests, ASIS, PSIS
- ischium: ischial spines, ischial tuberosities, ischiopubic ramus
- pubis: superior pubic rami, pubic tubercle, pubic arch
Name and describe the types of pelvic joint.
- sacroiliac joint: synovial anterior, syndesmoses posterior
- hip joint: synovial
- pubic symphysis: secondary cartilaginous
Define the foetal fontanelles and vertex.
- fontanelles: soft spots between sutures which have not yet ossified
- anterior fontanelle is largest. additional fontanelles: posterior and lateral
- vertex: area between fontanelles and parietal eminences
Name the two main measurements in foetal head lengths.
- occipitofrontal diameter
- biparietal diameter
Describe how the foetal head moves through labour.
- pelvic inlet: transverse position
- through pelvic cavity: flexed position, head should rotate to chin on chest
- pelvic outlet: occipitoanterior, extension of head on neck
Describe the meaning of ‘station’ in regards to foetal head position.
- distsnce of foetal head from ischial spines.
- +ve: head inferior to spines
- -ve: head is superior to spines
Describe the three main pathways of pain in the pelvis.
- superior pelvic [visceral afferents, running alongside sympathetic fibres to T11-L2]
- inferior pelvic [visceral afferents running alongside parasympathetic fibres to S2-4]
- sup/inf divided by peritoneum
- perineum [below levator ani; somatic sensory to pudendal nerve and S2-4]
What are the options of anaesthetic during labour?
- spinal, epidural anaesthetic; can result in vasodiiation and hypotension
- pudendal nerve block [passes posterior to lateral sacrospinous ligament, therefore ischial spine used as guide]
- epistolomy - skin/perineal muscles cut to ease delivery
Describe the embryology of the placenta. 
- trophoblast implants into uterus and becomes the placenta
- epi- and hypoblast develop into the the trilaminar disc
- the trophoblast (chorion) develops into the synctiotrophoblast, which develops into lacunae
Describe the maternal and foetal circulation via the placenta.
- foetal umbilical cord conveys umbilical arteries and veins into placenta
- arteries and veins penetrate the chorionic villi
- these vessels come into close contact with maternal vessels (not direct contact) to allow material diffusion
Describe the 3 main factors that enable oxygen diffusion from the mother to the foetus.
- increased ability of Hb to carry oxygen
- increased Hb concentration in foetal blood
- Bohr effect: foetal blood can carry more O2 in decreased CO2
Which drugs have a propensity to cross the placenta?
carbamazepine, tetracyclines, alcohol, nicotine, heroin, cocaine, caffeine etc.
How can serum HCG be used to gauge foetal status in pregnancy?
- doubles every 48h in a singleton early pregnancy (normal)
- static, slow rising (ectopic)
- falling (failing pregnancy)
Describe the hormonal effects during pregnancy of HPL, progesterone, oestrogen, and placental CRH.
- HPL: GH-like effects (protein tissue formation), increased foetal glucose, breast development
- progesterone: decidual cells, decreased uterine contractility, preps for lactation
- oestrogen: increases uterus size, breast size, relaxes ligaments
- CRH: aldosterone (HTN), cortisol (insulin resistance, GDM)
Describe the systemic changes associated with pregnancy.
- cardiovascular: inc CO, HR; dec BP, SVR, serum colloid osmotic pressure; minor ECG changes, functional murmurs
- renal: inc plasma flow, GFR, urine formation, proteinuria; dec creatinine
- GFR inc when supine, extra inc when lateral asleep, and dec when upright
- pulmonary: inc CO2 sensitivity, need for O2 consumption, RR, TV/MV; VC constant
- haem: inc PV, erythropoeisis, dec Hb by dilution; hypercoaguable state
- GI: weight gain, inc need for kcal (200/day), protein, folic acid, vitamin D, Fe, B vitamins for erythropoeisis
Name the three main stages of labour.
- cervical dilation (8-24hr)
- passage of foetus (mins - 120m)
- expulsion of placenta
Describe the hormonal effects leading to lactation.
- oestrogen: growth of ductile system
- progesterone: lobule-alveolar system, both of which inhibit milk production
- PRL: induces high milk production and colostrum secretion
- oxytocin: helps with milk let-down reflex
Name the layers of the abdominal wall, their blood supply and innervation.
- skin, superficial fascia, rectus sheath, rectus abdominus, external oblique, internal oblique, transverse abdominus, peritoneum
- superior epigastric (internal thoracic), inferior epigastric (external iliac), intercostals and subcostals
- 7th-11th intercostal, subcostal -> thoracoabdominal, iliohypogastric, ilioinguinal nerves
Describe how symphysis-fundal height (SFH) changes with gestation time.
- cannot normal be measured until 12wk
- normally gestation week = SFH (cm), +/- 3cm
- SFH falls at week 40 as the foetus prepares for birth.
Name the four main types of O&G incision.
- laparotomy (midline incision)
- laparoscopy (umbilical +/- lateral ports)
- hysterectomy (vaginal or abdominal)
A physiological process during which the foetus, membranes, umbilical cord, and placenta are expelled.
It is associated with regular painful contractions with increasing frequency, duration, and intensity
Describe the hormonal changes that occur during and preceding labour .
- prostaglandins are released, triggered by oestrogen, oxytocin, and pulmonary surfactant.
- CRH and cortisol help trigger oestrogen release
- oestrogen blocks the release of progesterone (which blocks labour)
- oxytocin produced by Ferguson reflex, as well as decidua and placenta. PLC activity causes Ca2+ release and uterine contraction
Describe what occurs during cervical ripening of labour.
- decreased collagen within fibroblasts and myocytes and increased hyaluronic acid cause the cervix to become soft/stretchable
- progressive contractions cause effacement and dilatation of the cervix due to shortening of upper section and thinning of lower section
Name and describe the four types of pelvis.
- gynaecoid: most suitable for childbirth
- android: heart shaped inlet, more common in African-Americans
- anthropoid: oval-shaped, large AP diameter, shorter TV diameter
Define the puerperium and how the lochia (vaginal discharge) changes during this time.
- a period of repair and recovery after birth, where tissues return to their non-pregnant state
- it lasts ~6wk, endometrial lining regenerates by day 7, and the fundus by day 14
- rubra (red) 3-4d –> serosa (brown-red) 4-14d –> alba (yellow) 10-20d
Describe the two main functions of colostrum.
- provides immunological support to baby
- helps develop gut microbiome (sterile before this)
Describe the changes that occur in the foetal lungs at birth.
- lung filled with fluid, secreted by own epithelium, essential for normal growth
- advancing gestation causes type 2 pneumocytes to secrete surfactant
- hormonal factors (cortisol, thyroid hormones, catecholamines) trigger resorption of fluid
- C/S can cause lack of these hormones and transient tachypnoea of the newborn (TTN)
Name how baby loses heat, and the main physiological source of heat.
- radiation, convection, conduction, evaporation
- brown fat lipolysis (laid down between scapulae and internal organs)
Describe the pathology of physiological foetal jaundice.
- foetal Hb is disadvantageous after birth so is broken down
- this causes high levels of bilirubin, pathways for breakdown are immature
- risk of kernicterus
Describe the makeup of ducts and tubules in the breast.
- basic unit is the terminal ductal lobular unit (TDLU), which consists of acini (glands) and tubules (intraductal)
- lactiferous ducts open into the lactiferous sinus, which then open to the nipple
Describe the histology of the breast tubules.
- basement membrane > myoepithelial [MEp] cells / contractile cells / basket cells > epithelial ducts (simple columnar / cuboidal in smaller ducts, then stratified squamous in larger)
- surrounded by blood vessels, leukocytes and fibroblasts
Describe the makeup and release of breast milk.
- lipid 3.5%; leaves the cell via apocrine secretion, surrounded by cytoplasm
- protein [lactalbumin, casein] 1.5%; produced in the rER, packaged in the Golgi, secreted by exocytosis
- water 83%
- carbohydrate [lactose] 7%
- ions, vitamins, IgA
Describe the vascular and lymphatic supply of the breast.
- arterial: lateral thoracic > lateral mammary; thoracoacromial > internal mammary
- venous: medial and lateral mammary veins
- lymph: >75% to axillary nodes, remainder to parasternal and abdominal nodes
Describe the histology of the nipple.
- keratin > nipple skin
- sebaceous glands open directly onto the skin, as there are no hair follicles
- suspensory ligaments of Cooper keep nipple erect
- dense, irregular connective tissue formed of collagen and smooth muscle under the skin