Repro physio + histo Flashcards
Describe how hormones lead to development of male & female genitalia
Male
SRY -> TDF -> Testes
Sertoli cells -> MIS/AMH -> Mullerian duct regress
Leydig cells -> Test -> Wolffian duct dev
Female is lack of both
What develops from the Wolffian duct?
Vas deferens
Epididymis
Seminal vesicles
What develops from Mullerian duct?
Uterus
Fallopian tube
Upper vagina
What causes the external genitalia to develop? (M&F)
DHT / Estradiol
What is X0 chromosome called?
Turner syndrome
What is XXY chromosome called?
Klinefelter syndrome
True hermaphrodite is presence of gonadal tissue & germ cells of both sexes in 1 person, what is pseudohermaphrodism?
Which is more common?
Inconsistency between internal & external genitalia
2 Examples of pseudohermaphrodism
AIS
5-alpha-reductase deficiency
describe spermatogenesis (making) and spermiogenesis (maturing)
In sertoli cells, FSH triggers production of sperm (spermatogonium -> spermatocyte -> spermatid -> spermatozoon)
ABP from sertoli binds to T from leydig to form a complex, transporting it to the semineferous tubules, where 5-a-reductase makes T into DHT
DHT for dev of prostate to head
Activin stimulates Ant pit
Inhibin & follistatin suppresses Ant pit
FSH and estrogen needed for maturation of sperm
5a-reductase deficiency vs AIS
Wolffian structures present vs lack of int structures
Puberty vs no puberty
Kallmann syndrome vs Klinefelter/turner syndrome
Low GnRH, FSH, LH vs
normal to elevated GnRH, FSH, LH
Describe histology of ovary
On the surface of the ovary, the stroma is much condensed and forms a layer called the tunica albuginea, composed of short connective tissue fibres with fusiform cells between them.
• The cortex contains ovarian follicles in different stages of development.
• The stroma is found throughout the ovary, both in the outer cortex and the inner medulla regions. It provides structural support and a microenvironment for the development and function of ovarian follicles.
• Medulla: The medulla is a loose connective tissue with abundant blood vessels, lymphatic vessels, and nerve fibres.
• Hilum: The hilum is the entry and exit point for blood vessels.
What layer surrounds the ovaries? (outside tunica albuginea)
germinal epithelium (misnomer, actl part of visceral peritoneum)
- 90% of ovarian cancers
Describe oogenesis
Oogonium -(mitosis)> primary oocyte -> 1st meiotic division (puberty) -> secondary oocyte -> 2nd meiotic division (if fertilised) -> ovum
Describe histology of primordial follicle
Primary oocyte surrounded by single layer of follicular cells
Describe histology of primary follicle
In to out
Primary oocyte
Zona pellucida
Follicular cells (multiple layers)
Theca cells (stroma)
Function of zona pellucida
Prevent polyspermy
Describe histology of secondary follicle
In to out
Oocyte
Follicular antrum (fluid) next to oocyte
Granulosa cells (multiple layers, make estrogen)
Theca cells (stroma)
Describe histology of Graafian/mature follicle
In to out
oocyte
zona pellucida
corona radiata (protects ovum)
Follicular antrum (big af) next to these
cumulus oophorus (granulosa/follicular cells)
Ovulation - mature follicle ruptures, oocyte + zp + cr expelled into peritoneal cavity
What does ruptured follicle become?
Corpus luteum
Function of corpus luteum
If fertilisation - produces progesterone to maintain uterine lining by increasing perfusion to spiral arteries
After 3-4 months placenta takes over fx
What stops the corpus luteum from degenerating?
hCG produced by syncytiotrophoblastic cells surrounding embryo
Used in pregnancy tests (immunoassay)
Risk factors of ectopic pregnancy
Hx of tubal surgeries
Pelvic inflammatory diseases
Contraceptive devices
Describe histology of fallopian tube
Simple columnar epithelium
surrounded by circular and longitudinal muscle layers
outer serosa
epithelium
- ciliated cells (move ovum to uterus)
- secretory (peg) cells (nutrients for ovum)
Describe histology of uterus
Endometrium (Lined by simple columnar)
- Functional layer
- Basal layer
Myometrium
- Progesterone - relaxes
- Estrogen - growth + contraction
- Oxytocin - contracts harder
Perimetrium
Describe histology of cervix
Endo (simple columnar epi)
Ecto (non keratinized strat squam epi)
Btwn is transformation zone (squamo-columnar junction)
During menstrual cycle, stroma volume varies, causing TZ to evert - exposed to harsh vaginal env - more susceptible to infection
Obstruction of glands = Nabothian cysts
During ovulation - watery mucous
Luteal phase - viscous mucous
Describe histology of vagina
Non-ker strat squam epi
Lamina propia (elastic & collagen fibres)
Muscular layer - smooth, ill-defined layers
Adventitia
No glands!
Describe histology of breast
In to out
Lumen (can have milk)
Luminal cells (most malignant cancers) - prolactin (produces milk if at terminal duct lobular unit)
Myoepithelial cells - oxytocin
Basement membrane
What’s in breast milk?
Glycogen
IgA
2 parts of placenta
Fetal - chorionic plate
Maternal - decidua basalis
What produces what? Hormones in pregnancy. Function?
Progesterone & estrogen (estriol)
- early - Corpus luteum
- late - placenta
Progesterone
- support endometrium
- INHIBIT myometrial contraction
- suppress maternal immune response to fetal antigens
Estrogen
- Growth of uterus & its blood flow
- Enchance fx of progesterone & oxytocin
- Fetal dev
- Breast cell proliferation & fat deposit
Human placental lactogen (hPL)
- by syncytiotrophoblasts
- support fetal nutrition
Prolactin
- Ant pit
- stimulate milk production
Relaxin
- Soften cervix, loosen connective tissues of pelvis
What makes what + fx of hormones in parturition
Progesterone
- inhibit phospholipase A2 -> PGs
- suppresses uterine contractions
Estrogen
- opposite
Prostaglandins
- by myometrium, decidua, chorion
- sharp increase before labour
- STARTS uterine contractions + cervical ripening & dilation
Oxytocin
- pos ant
- uterine contraction (MAIN)
- milk ejection
Relaxin
- by corpus luteum & placenta
- binds to LGR7 & 8
- pregnancy -> increase cardiac output, renal blood flow, arterial compliance
- parturition -> more oxytocin receptor, assist cervical opening & soften pubic symphysis
Feedback loop of birth
Fetus head push against cervix
Activate stretch receptors
Send signal to hypothalamus
Secrete oxytocin from Pos Pit
Stronger uterine contractions
positive feedback loop
What does prolactin inhibit
GnRH
