PBL 1 Flashcards
what is sexual behaviour?
the process by which we demonstrate and express sexuality
is sexuality biological?
there is evidence to suggest a relationship between homosexuality and certain regions of the X chromosome but its not definite
what are primary sex characteristics?
characteristics related to the reproductive system e.g. penis
what are secondary sex characteristics?
those unrelated to the reproductive system e.g. breasts or facial hair
what is oxytocin?
a hormone released during sexual intercourse when an orgasm is achieved
what is the role of vasopressin?
to form male arousal
what increases and decreases female motivation for sexual behaviour?
increases= oestrogen decreases= progesterone
what are sex steroid examples?
progesterone, oestrogen and testosterone
what’s the role of sex steroids?
crucial for the proper development and function of the body; they regulate sexual differentiation, the secondary sex characteristics and the sexual behaviour patterns.
what are steroids derived from?
acetate-> cholesterol….-> steroids
where are steroids synthesised?
in the adrenal cortex, gonads and placenta (within the mitochondria and smooth ER)
what are effects of oestrogen?
maintain body temp, helping against memory loss, regulating cholesterol production, stimulating ovary maturation and starting menstruation, helps maintain a lubricated and thick vaginal lining, stimulates breast development, prepares breast glands for future milk production, helps prepare the uterus to nourish a developing foetus and helps to preserve bone density.
what are effects of progesterone?
reducing hot flushes and vaginal dryness, fights fatigue, improves mood and sleep, alleviates skin dryness, wrinkling and thinning, prevents loss of bone density and fights weight gain
what are androgens?
hormones which play a role in male traits and reproductive activity. E.g. testosterone
what is the function of androgens?
male sexual and reproductive function; the development of secondary characteristics and they affect bone + muscle development and metabolism.
describe follicle maturation?
primordial follicle -> primary follicle -> secondary follicle -> (preantral) -> tertiary follicle -> preovulatory folllicle (antral)
what is a primordial follicle?
an oocyte surrounded by a flat layer of granulosa cells, arrested in prophase of meiosis
what is a primary follicle?
an oocyte surrounded by layers of granulosa cells, surrounded by layers of theca cells
how long does it take for primordary follicle-> primary follicle?
70 days
what is follicular trickle?
most preantral follicles are lost to atresia, but if it’s developing alongside the correct amounts of LH and FSH then folliculogenesis occurs
describe a preovulatory follicle?
an oocyte surrounded by a cumulus oophories surrounded by an antrum, surrounded by granulosa cells and a layer of theca cells
describe the follicular phase of the menstrual cycle?
The hypothalamus releases GnRH which stimulates the anterior pituitary to secrete FSH and LH. LH acts on theca cells to produce androgens. FSH binds to granulosa cells which causes expression of androgen aromatase which changes androgens to oestrogen. Oestrogen at low concentrations, inhibits LH and FSH secretion from the anterior pituitary. Androgens stimulate the growth of follicles which causes production of AMH- this regulates the growth of neighbouring follicles. As follicles mature, oestrogen levels rise more and beyond the threshold, and stimulate the release of a large amount of LH. This triggers ovulation of the dominant follicle- releasing of the oocyte.
what does AMH do?
regulates the growth of neighbouring follicles
describe how androgens are converted to oestrogen?
LH acts on theca cells which causes production of androgens. FSH binds to granulosa cells causing them to produce androgen aromatase which turns androgens to oestrogen
what do androgens do?
stimulates the growth of follicles
what is a corpus luteum?
the preovulatory follicle that has lost the oocyte in ovulation
describe what happens in the luteal phase of menstruation?
The follicle has now become a corpus luteum which secretes oestrogen, inhibin and progesterone as it slowly degrades. Inhibin prevents FSH being released as we don’t need any more follicle maturation. Progesterone inhibits the hypothalamus from producing GnRH which, in turn, inhibits LH and FSH release. Progestestone also stimulate endometrial growth to prepare the uterus for a fertilised egg to implant
describe the luteal phase if there’s no fertilised egg?
the corpus luteum degenerates to allow a new set of follicles to mature. Progesterone levels lower to stop the inhibition of GnRH and a new menstrual cycle can then occur.
what does inhibin B do? where is it released from?
negative regulates FSH levels
Sertoli cells
what is the uterine cycle?
the preparation and maintenance of the uterus lining to receive a fertilised egg
what are the phases of the uterine cycle?
menstrual phase proliferative phase and the secretory phase
what is the menstrual phase of the uterine cycle?
from day 1 of follicular phase, shedding of uterine lining=menses,
what is the proliferative phase of the uterine cycle?
oestrogen levels low but rising and endometrium begins to regrow to prep for a possible pregnancy
what is the secretory phase of the uterine cycle?
begins on day of ovulation and is charcterised by significant levels of progesterone and oestrogen, blood supply to endometrial tissues is remodelled
what does the length of the follicular phase depend on?
the velocity of growth of the ovarian follicles
what does the length of the luteal phase depend on?
the life span of the corpus luteum
when is the early follicular phase?
the first day of the cycle and ends when oestradiol begins to increase. It is characterised by increasing LH and FSH and constant low levels of oestradiol.
when is the late follicular phase?
the increase in oestradiol and ends at its preovulatory peak. It is characterised by increasing oestradiol and decreasing FSH and LH levels.
describe the action of the combined pill?
prevents ovaries from releasing an egg each month, thickens mucus in the neck o the womb, thins the lining of the womb
describe the action of the progesterone only pill?
thickens the mucus in the cervix to stop the sperm reaching the egg
describe the action of the morning after pill?
works by delaying the increase in the hormone which starts ovulation (progesterone)
describe anti androgens?
prevent androgens from mediating their effects by binding to androgen receptors and/or suppressing androgen production. Can be used for treatment of prostate cancer, enlarged prostate, scalp hair loss, overly high sex drive etc…
describe the action of testosterone replacement therapy preparations?
- it returns serum testosterone levels to within a physiological range and can improve hypogonadal symptoms.
how often does the average adult engage in sex a year?
54 times- varies a lot
what is a normal, healthy sex drive?
whatever the person is comfortable with
what could be some causes of lower sex drive?
menopause, culture, religion, mental health, age, obesity, chronic conditions, pregnancy, relationship satisfaction, medication, chemotherapy, female hormonal contraception, antidepressants
how can you increase sex drive?
sex therapy, increase sleep, aphrodisiac, exercise and testosterone therapy
what are some important things to remember when in a consultation with someone with a low sex drive?
could be embarrassing
there’s a lack of language to describe sensations and body parts
assumptions about gender and another’ persons experience of sex
assumptions about what is normal and where penetration is (own bias)
cultural norms must be madeaware of
is it safe? STIs? law? violence? payment? consent?
describe oogenesis?
before birth, the diploid oogonium undergoes mitotic devision to produce a primary oocyte- arrested in prophase. some get out of meiotic arrest and continue the first meiosis to produce a secondary oocyte and a first polar body. second meiotic cell division then occurs when a sperm fuses with an egg to produce a mature ovum and another polar body
