lecture 38 - coitus, fertilisation and contraception Flashcards
what does the word coitus mean
sexual intercourse = semen released into upper part of the vagina
what is the erectile tissue of the penis surrounded by
different layers of fasica
what is the trabecula in the penis
smooth muscle fibres
what is the lucunae of the penis and what happens during and erection
columnar tissue that fills with blood during an erection
- this causes them to squish against the trabaculae
- which push against the fasica
- this compresses the venous plexua (minimizes blood exsiting the penis and returning to the body)
why is the fasica that surrounds the corpus spongiosom not as ‘erectile’
it is not as dense or fibrous because it doesn’t become as erect because it can not block the urethra
blood flow from the adbominal aorta to the internal pudendal artery
- abdominal aorta
- common illiac artery
- internal iliac artery
- internal pudendal artery
what is the gonadal artery in males and females
males - testicular artery
females - ovarian artery
what does the internal pudendal artery feed
perineum and external genetalia including penis
where is the fasica in the penis
around the venous plexus
what is the pudendal nerve
supplies sensory and somatic motor innervation to perineum and external genitalia, including penis
what kind of nervous system response is an erection and what does it stimulate
parasympathetic
- stimulates production of nitric oxide (vasodilator)
- causes deep arteries to dilate and fill lacunae in the corpors cavernosa
what kind of nervous system response is ejaculation and what does it stimulate
sympathetic
- stimulates contraction of smooth muscle
- reproductive ducts
- accessory glands
the first stage of the male sexual act and what happens
erection
parasympathetic response to stimuli
- arteries in erectile tissues dilate
- erectile tissue becomes engorged with blood
what is the second stage of the male sexual act and what happens
emission
- sympathetic response
- smooth muscle of the ductus deferens contracts to move sperm into ampulla
- smooth muscle of the ampulla, semnial vesicle and prostrate gland contract moving sperm and seminal fluid into urethra
what is the third stage of the male sexual act and what happens
expulsion
semen in urethra activates somatic and sympathetic reflexes
- contractions of urethral and smooth muscles
- pelvic floor muscles contract
semen is ejected
what is the fourth stage of the male sexual act and what happens
resolution
- blood flow to penis is reduced
- penis becomes flacid
what happens in the female sexual act
- engorgment of clitoris, labia and vagina in response to autonomic stimulation
- lubricating fluid secreted through vaginal wall, secretion of mucus into vestibule
- rhythmic contraction of vaginal, uterine and pelvic floor muscles
what happens after insemination
- sperm travel to uterine tube for fertilisation (ampulla)
- sperm fuses with secondary oocyte
- oocyte completes meiosis II
- fertilised oocyte /ovum known as zygote
- zygote initiates cleavage (takes about 7 days) and travels towards uterus for implantation
what does the combined pill contain and what does it do
estrogen and progestin
- suppress ovulation (affect feedback loops to hypothalamus and pituitary)
- affect mucus produced by cervix
what does the progesterone only pill effect
cervical mucus
what does implant / injectable progestin do
act primarily by disrupting follicular growth and ovulation
