Physiology and pathology Flashcards
Gonadotrophin releasing hormone (GnRH) is secreted from where and stimulates the release of what?
- secreted from the hypothalamus
- stimulates the release of follicle stimulating hormone (FSH) and luteinising hormone (LH) from the anterior pitutiary
What is the role of FSH?
Initiates follicular growth
What is the role of LH?
Stimulates the further development of follicles
What stimulates the ovarian follicles to secrete oestrogen?
- FSH
- LH
What secretes progesterone?
The corpus luteum
When does the menstrual phase occur?
Usually the first five days of the cycle
What occurs in the ovaries during the menstrual phase?
- under the influence of FSH primary follicles develop into secondary follicles
- this may take several cycles
What occurs in the uterus during the menstrual phase?
- a fall in oestrogen and progesterone stimulates release of prostaglandins causing uterine spiral arterioles to constrict
- the cells supplied by these arterioles die and the entire stratum functionalis of the endometrium sloughs off leaving the thin stratum basalis
- 50-150ml of blood tissue, mucus and epithelial cells shed from the endometrium passing through the cervix and vagina
- normal blood loss is 5-80ml
How long does the preovulatory phase last?
The time between menstruation and ovulation varies in length and has the main impact on cycle length
What occurs in the ovaries in the preovulatory phase?
- secondary follicles secrete oestrogen
- one secondary follicle outgrows the rest to become dominant and develops into the graafian follicle
What occurs in the uterus in the preovulatory phase?
- oestrogens released into the circulation by the growing secondary follicles and graafian follicle stimulate growth of the endometrium
- cells of the stratum basalis undergo mitosis and produce a new stratum functionalis
- endometrial thickness double to 4-10mm
When does ovulation occur?
Ovulation occurs on day 14 in a 28 day cycle (14 days before menstruation)
What occurs in the ovaries during the ovulatory phase?
- oestrogen stimulates more GnRH release
- this leads to an increase in LH and FSH release
- LH causes the rupture of graafian follicle and expulsion of a secondary occyte (approximately 9 hours after the LH surge)
- the occyte is taken into the fallopian tube
What occurs in the uterus during the ovulatory phase?
- progesteron and oestrogen continue to stimulate proliferation to the endometrium
When does the postovulatory phase occur?
This is the most constant phase and routinely last for 1 days with little variation
What occurs in the ovary in the postovulatory phase?
- the collapsed follicle becomes the corpus luteum under the influence of LH
- the corpus luteum secretes progesterone, oestrogen, relaxin and inhibin
- if fertilisation does not occur this secretory activity declines after 2 weeks and a new cycle begins
What occurs in the uterus during the postovulatory phase?
- progesterone and oestrogen promote growth and coiling of the endometrial glands, vascularisation and further thickening of the endometrium (12-18mm)
- endometrial glands begin to secrete glycogen
Name symptoms of PMD
Physical; - breast tenderness - bloating - headache - skin disorder - weight gain - swelling - joint pain - fatigue Psychological; - mood swings - anger - depression - tension - not in control - lack in interest - loneliness - hopelessness - suicidal ideation Behavioural; - sleep disturbance - change in appetite - restlessness - poor concentration - confusion - social withdrawal
Name drugs that can be used for ovulation suppression in PMD
- yasmin and eloine (1st line)
- GnRH agonists
- danazol
- oestrogen
- bilateral oophrectomy and hysterectomy with add back oestrogen only
Describe the management of heavy menstrual bleeding
- minera coil (1st line)
- tranexamic or COC (2nd line)
- norethisterone or DMPA (3rd line)
- 4th line is surgical management
Name causes of heavy menstrual bleeding
- fibroids
- polyps
- adenomyosis
- coagulopathy
What are fibroids?
Benign smooth muscles tumours of the uterus
Describe adenomyosis
- defined as the presence of non-neoplastic endometrial glands and stroma in the myometrium
- associated with hyperplasia and hypertrophy of the surrounding myometrium
- associated with a history of c section, uterine curettage, surgical termination of pregnancy, increasing age, oestrogen exposure and tamoxifen use
Describe surgical options for heavy menstrual bleeding
- polypectomy
- endometrial ablation
- uterine artery embolisation
- myomectomy
- hysterectomy
Name indications for endometrial sampling
- abnormal uterine bleeding
- investigation for infertility
- spontaneous and therapeutic abortion
- assessment of response to hormonal therapy
- endometrial ablation
- work up prior to hysterectomy for benign indications
- incidental finding of thickened endometrium on scan
- endometrial cancer screening in high risk patients
What is menorrhagia?
Prolonged and increased menstrual flow
What is metorrrhagia?
Regular intermenstrual bleeding
What is polymenorrhoea?
Menses occuring at <21 day interval
What is polymenorrhagia?
Increased bleeding and frequent cycle
What is menometrorrhagia?
Prolonged menses and intermenstrual bleeding
What is amenorrhoea?
Absence of menstruation >6 months
What is oligomenorrhoea?
Menses at intervals of >35 days
Name causes of abnormal uterine bleeding in adolesence / early reproductive life
- DOB usually due anovulatory cycles
- pregnancy / miscarriage
- endometritis
- bleeding disorders
Name causes of abnormal uterine bleeding in life / perimenopause
- pregnancy / miscarriage
- DUB; anovulatory cycles, luteal phase defects
- endometritis
- endometrial / endocervical polyp
- leiomyoma
- adenomyosis
- exogenous hormone effects
- bleeding disorders
- hyperplasia
- neoplasia; cervical, endometrial
Name causes of abnormal uterine bleeding in post menopausal women
- atrophy
- endometrial polyp
- exogenous hormones; HRT, tamoxifen
- endometritis
- bleeding disorders
- hyperplasia
- endometrial carcinoma
- sarcoma
Describe how to sample the endometrium
Endometrial pipelle; - 3.1mm diameter, no dilatation needed - no anaesthesia - outpatient procedure - very safe - limited sample Dilatation and curretage; - most common operation performed on women - most through sampling method - can miss 5% hyperplasias / cancer
Name causes of endometritis
Micro-organisms; - nisseria - chlamydia - TB - CMV - actinomyces - HSV Inflammation without specific organisms; - intra-uterine contraceptive device - postpartum - postabortal - post curettage - chronic endometritis - granulomatous - associated with leiomyomata or polyps
What is a molar pregnancy?
- an abnormal form of pregnancy in which a non-viable fertilised egg implants in the uterus (or tube)
- a form of trophoblastic disease which grows as a mass characterised by swollen chorionic villi, categorised as partial moles or complete moles
How does a complete mole occur?
- a single or two sperm combining with an egg which has lost its DNA
- the sperm then reduplicates forming a complete 46 chromosome set
- only paternal DNA is present in a complete mole
How do partial moles occur?
- when egg is fertilised by two sperm or by one sperm which reduplicates itself yielding the genotype 69, XXY (triploid)
- partial moles have both maternal and paternal DNA
What type of mole has a higher risk of developing into choriocarcinoma?
A complete hydatidiform mole
What is adenomyosis?
- endometrial glands and stoma within the myometrium
- casues menorrhagia / dysmenorrhoea
