reproduction Flashcards
what are the functions of the female reproductive system
-produce haploid gametes (ova from oogenesis)
-facilitate fertilisation with spermatozoan (meiosis II complete)
-site for implantation of the embryo
-provide physical and nutritional needs to nurture neonate after birth (mammary glands)
what are the ovaries
-female gonads for development and maturation of the ova
-inner medulla- blood vessels and sympathetic vessels
-cortex- outer germinal epithelial layer containing oocytes (enclosed within follicle- folliculogenesis(developing by))
-ovarian follicular celles secrete steroid hormones : granules and theca (progesterone)
-hormones= endocrine and paracrine, for ova development, uterus breast and bone
what are the fallopian tubes
-transport egg from ovary to uterus
-infundibulum with fimbriae (capture egg as its released and transmits this to the uterus)
-ampulla and isthmus
-smooth muscle in walls- peristalsis
-highly folded mucosa- ciliated and secretory cells
what is the uterus
-where ova end up
-consists of perimetric, myometrium and endometrium (last one most important)
-endometrium is a simple columnar epithelial cells with leukocytes and macrophages, contains lamina propria which are cell rich connective tissue, also contains compound tubular glands and spiral arteries
what is the cervix
-cervical canal connects uterus to vagina
-interior os and exterior os as its margins
-cervical glands secrete mucus preventing microbes reaching uterus
what is the vagina
-birth canal (8-10cm)
-thin distensible walls of adventitia, muscular and mucosa
-stratified squamous epithelium rich in glycogen: formed by bacteria to lactic acid producing pH 3.5-4 inhibits pathogens, antigen- presenting dendritic cells - both in which ensure uterus is in a good environment for a foetus to grow
how does the neuroendocrine system control ovarian and endometrial cycles
-two cycles: ovarian and endometrial
-hypothalamic-pituitary-gonadal axis (HPGA) drives menstrual cycle
-hypothalamic neurones releases gonadotropin-releasing hormone (GnRH)
-hypophyseal portal system connects hypothalamus to anterior pituitary
-G protein coupled GnRH receptors on pituitary endocrine cells (gonadotrophs) release gonadotropins : follicular stimulating hormone FSH and luteinising hormone LH)
what is he feedback of hypothalamic-pituitary-gonadal axis
-FSH+LH stimulates ovarian follicular cells to secrete hormones (from cholesterol)
-theca cells secrete progesterone
-granulosa cels - 17beta-oestradiol: inhibin (-ve, decrease FSH), active (+ve, increase FSH)
-produce mature gametes
how is the ovarian cycle regulated
-HPGA is controlled by negative and positive feedback, dependent upon phase
-follicular phase- 17beta-oestradiol negative feedback on hypothalamus (except prior to ovulation mid cycle)
-luteal phase progesterone major hormone of negative feedback
-midcycle: follicular cell proliferation leads to estradiol rising sharply to a critical levels which leads to +ve feedback on GnRH secretion and FSH/LH by up regulation of GnRH receptors in AP this leads to a burst of secretion triggers ovulation of mature oocyte
what happens in the endometrial cycle
-17beta-oestradiol and progesteron control changes in endometrium, feedback regulation of FSH/LH, cervix and vagina
-cervical mucus: follicular phase - (17b-oe) mucus copious, watery and elastic, forms channels to propel sperm, secretory phase decreases progesterone and mucus becomes thick
what happens in the proliferation phase of the endometrial cycle
-secretion of 17b-oe increase markedly
-stimulates growth of endometrium, glands, storm and spiral arteries elongate
what happens in the secretory phase of the endometrial cycle
-following ovulation dominated by progesterone
-endometrial proliferation slows, thickness decreases
-glands- tortuous (folded) with accumulated glycogen vacuoles, increased mucus
-stroma- oedematous
-spiral arteries elongate and coil
-ending in menses (if no implantation)
what are hormonal contraceptives
-they alter hormonal balance to prevent pregnancy
-oral contraceptive pill
-numerous combinations: oestrogen and progesterone, progesterone only, monphasic/ fixed-combination and multphasic/ varying dose
what’s the mechanism of action
-feedback on hypothalamus decreases GnRh secretion
-feedback on anterior pituitary gonadotrophs inhibit FSH/LH and prevent ovulation
-low FSH insufficient to stimulate folliculogenesis meaning no development of follicles with a mature ova
-low LH inhibits ovulation
-progestin: cervical mucus thick/can’t which inhibits sperm penetration, decrease in uterus and fallopian tube motility, and decrease in endometrial glycogen (for blastocyst survival)
what’s the hormonal morning after pill
-higher dose preparations of oestrogen and progesterone: inhibits ovulation an interferes with implantations
-can be used a s post-coital contraceptive
