Reproductive system 5 Flashcards
Describe coitus
Intromission - Erect penis introduced into vagina
Insemination - Semen released into upper part of vagina
What are the stages of the male sexual act
Erection of sympathetic (parasympathetic)
Mucus secretion into urethra
Ejaculation - emission and expulsion
Resolution
What are the layer of fascia or the penis
Superficial fascia
Tunica albuginea
Deep (bucks) fascia
Compare structure of clitoris and penis
Share development origin
Tissue of clitoris are erectile - as in penis
Describe the branches of the abdominal aorta
Abdominal aorta - common iliac artery - internal iliac artery - internal pudendal artery
Where does the internal pudendal artery feed
Feeds perineum and external genitalia - penis
What are the artery branches to the penis
Artery to bulb
Urethral artery
Dorsal artery
Deep (cavernosal) artery
Describe the nerve supply of the penis
Richly innervated by sensory and motor nerves
Includes sensory fibres - responsive to touch, pressure, temperature
Pudendal nerve supplies sensory and somatic motor innervation to perineum and external genitalia
Autonomic innervation to penis derived from pelvic plexus
Describe parasympathetic control of male penis
Erection - Stimulates production of nitric oxide by deep arteries - dilate and fill lacunae in corpora cavernosa
Describe sympathetic control of penis
Ejaculation -
Stimulates contraction of smooth muscle
Reproductive ducts
Accessory glands
Describe somatic control of the penis
Ejaculation
Stimulates contraction of skeletal muscles around bulb of penis
Describe the erection phase of the male sexual act
Parasympathetic response to stimuli
Arteries in erect tissue dilate
Erectile tissue becomes engorged with blood
Describe emission stage of the male sexual act
Sympathetic response
Smooth muscle of ductus deferens contracts to move sperm
Smooth muscle of ampulla, seminal vesicles and prostate gland contract - moving sperm and seminal fluid into urethra
Describe expulsion stage of the male sexual act
Semen in urethra activates somatic and sympathetic reflexes
Contractions of urethral smooth muscles
Pelvic floor muscles contract
Semen ejected
Describe the resolution stage of the male sexual act
Blood flow to penis is reduced
Penis becomes flaccid
Describe the stages of the female sexual response
Engorgement of clitoris, labia and vagina - autonomic stimulation
Lubricating fluid secreted through vaginal wall - mucus into vestibule
Increased width and length of vagina - uterus elevates upwards
Rhythmic contraction of vaginal, uterine and perineal muscles
Describe fertilisation
Semen releases into upper part of vagina - insemination - sperm travels into ampulla
Sperm fuses with secondary oocyte - completes meiosis 2
Fertilized oocyte/ovum - zygote - initiates cleavage and travels towards uterus for implantation
What is contraception
Any method used to prevent pregnancy - regulate when and how many pregnancies
What are the natural methods of contraception
Rely on timing of coitus or behaviour - high failure rate
Rhythm method
Withdrawal method
Lactational infertility
Describe barrier methods of contraception
Caps, diaphragms - Imperfect barrier - used in conjunction with spermicidal foams/jellies/creams/sponges
Needs to remain at least 6 hours after intercourse - not commonly used anymore
Describe barrier methods of contraception
Condoms - cheap, readily available, easy to use, reduced risk of STIs
Describe steroid contraceptives for females
Contain estrogen and progestin
Suppress ovulation - feedback loops of hypothalamus and pituitary
Affect mucus produced by cervix - prevent sperm penetration
Describe progestin only contraception
Low does of progestin, Effects on cervical mucus
Subdermal implant/injectable progestins
- longer acting
- Acts primarily by disrupting follicular growth and ovulation
Describe Intrauterine devices (IUD)
Copper IUD - low grade inflammation, reduces sperm transport, toxic to oocytes and zygote, impairs implantation
Hormonal IUD - Contains progestins, affects cervical mucus - reducing sperm transport, Local affects on endometrium, may prevent ovulation
What are the types of serialisation
Tubal ligation - cut uterine tubes
Vasectomy - cut vas (ductus) deferens
