Repro Topic 1 - Female Reproduction Flashcards
Describe the structure of the suspensory ligament
- Lateral wall of the pelvus to the ovary
- Carries ovarian artery and vein
Describe primordial follicles
- At periphery of cortex
- Most numerous follicle type
- Single layer of squamous follicular cells
- Contain the immature primary oocyte
Give examples of disorders of hormone excess
- Polycystic ovarian syndrome
- Granulosa cell tumour
- Teratoma
How do steroid hormones function?
Lipid soluble - permeable to membranes, bind to intracellular receptors
List the phases of ovarian function during the menstrual cycle
- Follicular phase
- Luteal phase
Describe primary follicles
- Cuboidal stratified follicular cells - granulosa
- Contains the primary oocyte
- Follicular fluid between cells
Describe the arterial supply of the ovary
Ovarian artery - arises from aorta at the level of the renal artery
Describe the structure of the broad ligament
- Peritoneal sheet draped over uterus and uterine tubes
- Ovaries attached to posterior layer by short mesentery - mesovarium
What is the effect of aromatase excess?
- Excessive conversion of androgens to oestrogens
- Feminisation of male genitalia
Give examples of disorders of hormone resistance
- Testicular femininisation syndrome
- Reifenstein’s syndrome
- 5 alpha reductase type 2 deficiency
Describe common structural abnormalities of uterus
- 20% show retroflexion and retoversion (asymptomatic)
- Bicornate uterus = 2 separate
Describe the action of hormonal contraception
- Oestrogen and progesterone combination or continuous progesterone
- Selective inhibition of pituitary function - inhibition of ovulation
- Change in cervical mucous, uterine endometrium and motility/secretion in tubes
List disorders of steroidogenesis
- Congenital adrenal hyperplasia
- Aromatase deficiency
- Aromatase excess
What is the significance of the Pouch of Douglas
‘Backstreet’ abortions - sharp object up through vagina to the uterus, often accidentally perforates the pouch of Douglas, causing serious infection
Describe the structure of the ovarian ligament
Fibrous cord, links ovary to uterus
Give examples of disorders of hormone deficiency
- Hypogonadism
- Turner’s syndrome
- Klinefelter’s syndrome
- Kallman’s syndrome (low GnRH)
- Hypopituitarism
Describe the effects of the hormonal changes in the menstrual cycle on the cervix
- Late follicular phase - high oestrogen
- Increased vascularity, watery mucous (allows passage of sperm)
- External os open
- Luteal phase - high progesterone
- Thickens cervical mucous, reduces elasticity
List the types of abnormalities of female endocrine function
- Hormone excess
- Hormone deficiency
- Hormone hypersensitivity
- Hormone resistance
List the stages in follicle development
- Primordial follicle
- Primary follicle
- Secondary follicle
- Corpus luteum
Describe the layers of the walls of the uterine tubes
- Mucosa (thick muscosal folds in the ampulla)
- Epithelium - simple ciliated columnar with secretory cells
- Lamina propria
- Circular muscle
- Longitudinal muscle
- Serosa
Describe the arterial supply of the uterus
Uterine artery, branch of the internal iliac artery
How are female steroid hormones produced?
- Cholesterol is converted to pregnenolone then progesterone
- Later in the pathway, androstenedione is converted to oesterone by aromatase or testosterone
- Testosterone is converted to oestradiol by aromatase
- Oesterone is converted to oestradiol
Describe the components of the female reproductive system
- Paired gonads - ovaries
- Duct system - paired uterine tubes, single midline uterus, single midline vagina
Describe the uterine lining in the secretory stage
- Bigger more coiled glands
- More secretions for nutrition of the embryo (pre-implantation)
How do follicles change following ovulation?
- After ovulation, large follicle collapses and becomes the corpus luteum (temporary endocrine organ)
- Lutein cells from granulosa/theca cells
- Granulosa form most of the lutein cells, theca form the peripheral lutein cells
- Much larger than follicle
- Connective tissue septa and blood vessels form
What is polycystic ovarian syndrome?
- Common
- Clinical presentation - infertility (no ovulation, lack of menses - high androgens), weight gain, hirsutism, acne
- LH/FSH secretion out of balance - no negative feedback, continuous oestrogen production
- 2:1 LH:FSH ratio diagnostic
Explain negative/positive feedback in the menstrual cycle
- Oestrogen and progesterone
- Negative feedback effect on the pituitary and hypothalamus during most of the cycle
- Positive feedback effect on the pituitary and hypothalamus on days 12-14
How is sex hormone secretion controlled in females?
Hypothalamic-pituitary-ovarian axis
Describe androgen production
- Ovary - androstenediol, DHEA, small amount of testosterone
- Adrenal cortex - androstenedione, DHEA, DHEAS
- Androstenedione and androstenediol converted to testosterone
- DHEA converted to androstenedione or androstenediol
Where is the female reproductive system located?
In the pelvic cavity, the vagina extends through the pelvic floor
Where are female steroid hormones produced?
Produced in gonads, adrenal glands and the placenta
How is progesterone produced?
- Synthesised from cholesterol via pregnenolone
- Produced primarily in the corpus luteum, adrenal gland and placenta during pregnancy
How long does the follicular phase of the mentrual cycle last?
10-14 days
Describe the levels of progesterone and oestrogen in the follicular phase of menstruation
Low progesterone
High oestrogen - conversion of androgens to oestrogens via aromatase
Describe the hormonal changes which occur during the follicular phase of the menstrual cycle
- High FSH promotes development of follicles
- LH rises slowly, beginning 1-2 days after FSH increases
- Oestradiol production by follicles causes increased FSH/LH synthesis but inhibits secretion, especially of FSH, also promotes the proliferation of the uterine lining
- Granulosa cells produce inhibin, which inhibits FSH
- Towards the end of the follicular phase, progesterone begins to rise, high oestradiol causes LH secretion by gonadotropes (positive feedback)
- Stored LH is released - LH surge over 36-48 hours along with a smaller rise in FSH
- LH surge - enzymes to breakdown follicle wall and release mature oocyte (ovulation)
How long does the luteal phase of menstruation last?
14 days - usually constant
Describe the uterine lining in the menstrual stage
- If fertilisation/implantation don’t occur - death of corpus luteum, loss of hormone supply
- Spiral arteries become more coiled, vascular stasis leading to tissue death
- Active vasoconstriction then relaxation of arteries, flow of blood carries away dying tissue
- Surface layers (stratum functionalis) shed - stratum basalis remains as it has an independent blood supply from straight arteries, which are a source of regrowth in the next cycle
Where are the ovaries located?
- Variable position - especially after childbirth
- Near laterall wall of pelvic cavity, stabilised by ligaments
What is the function of progesterone?
- Endometrial development - smooth muscle control
- Maintenance of pregnancy (placenta)
- Mammary gland development
Describe the hormonal changes which trigger menstruation
- Inhibin inhibits FSH/LH release
- Corpus luteum degeneration, reduced progesterone
- Leukocyte infiltration of endometrium
- Spiral arteries breakdown
- Menstruation begins
List the peritoneal reflections (pouches) of the female reproductive system
- Rectouterine pouch (of Douglas) - deep pouch between uterus and rectum
- Utervesical (vesicouterine) pouch - dead end between bladder and uterus, shallow
Describe the effects of the hormonal changes in the stages of the menstrual cycle on the vagina
- Early follicular - low oestrogen
- Epithelium thin + pale
- Low follicular - high oestrogen
- Squamous cells mature, epithelial thickening
- Luteal phase
- Mature squamous cells shed as cellular debris
Describe the uterine lining in the proliferative stage
- Inner endometrium
- Simple columnar epithelium
- Long uterine glands
- Coiled arteries
- Superficial stratum functionalis and deep stratum basalis
- Smooth muscle myometrium - thickest in this stage (preparation to deliver child)
- Outer serosa or perimetrium
Describe the venous drainage of the uterus
Uterine vein, drains to the internal iliac vein
Describe the shape/size of the ovary
- Almond shaped
- 3cm in young women, get smaller with age
- Surface scarred and pitted due to ovulation
Describe the histological arrangement of the ovary
- Peripheral cortex - follicles
- Central medulla - blood vessels, nerves, lymphatics
What causes congenital adrenal hyperplasia? What are its effects?
- 21-hydroxylase or 11-beta hydroxylase deficiency
- Causes ambiguous genitalia, precocious puberty, anovulation, hirsutism
List the layers of the lining of the vagina
- Mucosa - stratified squamous non-keratinised epithelium, lamina propria
- Muscularis - smooth muscle arranged in longitudinal and transverse bundles
- Adventitia
Describe the hypothalamic-pituitary-ovarian axis
- Hypothalamus
- Neurosecretory cells release gonadotrophin releasing hormone into pulsatile portal vessels
- Activates GnRH receptors in the anterior pituitary
- Pituitary
- Anterior pituitary releases gonadotrophins (FSH/LH)
- Ovaries
- FSH - recruitment and growth of follicles (especially granulosa cells)
- LH - theca cell support, receptors expressed on maturing follicle, surge triggers ovulation
Give examples of disorders of hormone hypersensitivity
Hirsutism - excess body hair
Describe the location of the uterine tubes
- In free margin of broad ligament, 13cm long
- Not directly connected to ovary - open into peritoneal cavity
Where is the vaginal mucous produced?
From glands of the uterine cervix and small amounts from the great vestibular glands of Bartholin
Describe secondary follicles
- Antrum - fluid filled cavity
- Deep in cortex
- Multilayered follicular cells - granulosa, theca interna, theca externa
- Interna has many blood vessels, synthesises androgens from cholesterol, which are converted to oestrogens by granulosa cells
- Circular collagen fibres in externa
Describe the structure of the uterine tubes
- Infundibulum - first part, funnel shaped, opens into peritoneal cavity, has finger-like fimbrae
- Ampulla - middle section, where fertilisation occurs
- Isthmus - short narrow section, connected to uterine wall
- Interstitial/uterine part
Describe the shape and position of the uterus
- Midline, pear-shaped (fundus at top), bent forwards at 90 degrees to the vagina (anteversion)
- Body - bent forwards (anteflexion)
- Cervix (neck)
- Openings at each end - internal and external os
- Cervical canal between
- Fundus - rounded, projects up above level of uterine tubes
- Isthmus - narrowing between body and cervix
Describe the events of the luteal phase of menstruation
- Formation of corpus luteum from follicle
- Corpus luteum secretes mostly progesterone - peaks at 6-8 days after ovulation
- Progesterone causes development of the secretory endometrium
- LH/FSH decrease due to negative feedback - oestradiol and progesterone secretion decreases
- If implantation occurs - corpus luteum remains, supported by human chorionic gonadotrophin produced by the developing embryo
What is the function of the ovary?
- Endocrine and exocrine function
- Endocrine - main reproductive hormone source (progesterone and oestrogen)
- Exocrine - gamete production
How is it ensured that the fertilised oocyte will be able to pass the isthmus of the uterine tubes?
Zona pellucida keeps it the same size until passed the isthmus
How is does the uterine tube assist in conception?
- Peristaltic movements move along the tube to help sperm move along the tube to reach the ampulla, where fertilisation occurs
- Cilia on epithelial cells move the egg along the tube - undergo hypertrophy in the proliferative phase
Describe the circulating oestrogens
- Mix of oestrone and oestradiol
- Oestrone from ovary or converted from androstenedione
- Oestradiol from ovary - direct synthesis in developing follicles or conversion of oestrone
Describe the venous drainage of the ovary
Ovarian vein - left drains to left renal vein, right drains to inferior vena cava
Describe the events which occur in the follicular phase of menstruation
- Growth of a dominant follicle
- Development of primary follicles (from primordial)
- Development of secondary follicles
- Uterine changes (proliferative phase) - oestrogens from ovary act on endometrium causing thickening of stroma (connective tissue), elongation of uterine glands and growth of spinal arteries
- Ovulation (around day 14) - completion of first meiotic division of the oocyte within 36 hours of ovulation
List the ligaments of the female reproductive system
- Broad ligament
- Ovarian ligament
- Suspensory ligament
What is the function of oestrogens?
Development of secondary sex characteristics and regulation of the menstrual cycle
What is the effect of aromatase deficiency?
- Prevents oestrogen synthesis
- Ambiguous genitalia
List the stages which the uterine lining goes through in the menstrual cycle
- Proliferative stage
- Secretory stage
- Menstrual stage
