HUBS192 Lecture 38 - Coitus, Fertilisation and Contraception Flashcards
what is the definition of menarche?
the onset of the menstrual cycle
what is the definition of menopause?
the cessation of the menstrual cycle
what does GnRH from the hypothalamus directly regulate the secretion of? (2 hormones)
LH and FSH
during oogenesis, at what point of meiosis II is the secondary oocyte suspended?
metaphase II
what event during oogenesis causes the secondary oocyte cell cycle to resume from suspension?
fertilisation/ sperm penetration
what happens to the oocyte if the event of fertilisation/ sperm penetration does not occur?
atresia or degeneration
what is coitus in terms of intromission?
the erect penis is introduced into the vagina to transport the male gamete to the female gamete
what is insemination?
when semen is released into the upper part of the vagina
what is the function of insemination?
so that sperm can travel to the appropriate site for fertilsation which is the ampulla of the uterine tube
what is the determining factor of whether sperm can make it up the internal os and ampulla for insemination?
depending on the stage of the menstrual cycle will determine whether sperm can make it up to the internal os and the ampulla
what are the 4 stages of the male sexual act?
1) erection of the penis
2) mucus secretion into the urethra
3) ejaculation
4) resolution
what does an erection allow for?
an erection allows for intermission into the vagina
is the erection of the penis coordinated by the sympathetic or parasympathtic nervous system?
the parasympathetic nervous system
what does the mucous secretion into the vagina allow for?
allows for secretions from the bulbourethral glands to lubricate the urethra and remove residual urine?
what are the 2 phases of ejaculation?
1) emission phase
2) expulsion phase
is both phases of ejaculation coordinated by the sympathetic or parasympathtic nervous system?
both phases or emission and expulsion are coordinated by the sympathetic nervous system
what is the resolution stage of the male sexual act?
when the penis is flaccid
what follows the resolution stage of the male sexual act?
the refractory period
what is the bulbocavernosus muscle?
a muscle that encases the root of the penis
what is the bulbocavernosus muscle important for?
a muscle that is important in the ejaculation process
what do the venules in the penis form?
form a venous plexus
what are the erectile tissues of the penis surrounded by?
surrounded by different layers of the fascia
what are the 5 layers of the fascia that surrounded the erectile tissue?
1) lacunae
2) trabeculae
3) superficial fascia
4) tunica albuginea
5) deep (buck’s) fascia
what are the lacunae surrounded by and why?
surrounded by trabeculae for blood to encore the engorgement of the erectile tissue
what is the relationship between the structure of the clitoris and the penis?
the structure of the clitoris and the penis are homologous
what is the relationship between the erectile tissues in the clitoris and the penis?
the erectile tissues of the clitoris are the same as in the penis
what are the 4 branches of the abdominal aorta?
abdominal aorta –> common iliac artery –> internal iliac artery –> internal pudenendal artery
where does the testes originally develop and migrate down to?
testes originally develop in the abdomen and then migrate down and bring their vasculature with them
what do the testes bring down when they migrate down from the abdomen?
migrate down and bring their vasculature with them
what does the internal pudenal artery feed?
the internal pudenal artery feeds the perineum and the external genitalia including the penis
what are the 4 branches to the penis?
1) artery to bulb
2) urethral artery
3) dorsal artery
4) deep (cavernosal) artery
what are the 3 arteries in the penis?
1) dorsal artery
2) deep artery
3) urethral arteries
what are the 3 veins in the penis?
1) superficial dorsal vein
2) deep dorsal vein
3) subtunical veins
what is the nerve in the penis?
the dorsal nerve
what are the 2 arteries associated with the penis?
1) the internal iliac artery
2) the internal pudendal artery
what are lacunae surrounded by?
lacunae are surrounded by smooth muscle
what is an erection in terms of the increasing blood supply to the penis?
the lacunae fill with blood and the trabeculae relax and this places pressure that is being restrained by the fasa that decreases the venous return back to the body
what is the penis richly innervated by?
richly innervated by sensory and motor nerves
where is the penis particularly richly innervated by sensory and motor nerves?
particularly in the glands of the penis
what does the rich innervation of sensory and motor nerves include?
includes sensory fibres responsive to touch, pressure and temperature
what does the pudendal nerve supply?
supplies sensory and somatic motor innervation to the perineum and the external genitalia, including the penis through the dorsal nerve
what innervation to the penis is derived from the pelvic plexus?
autonomic innervation to the penis derived from the pelvic plexus (both the parasympathetic and sympathetic nervous systems)
what nervous system innervates the pelvic plexus?
both the parasympathetic nervous system and sympathetic nervous system
where does the parasympathetic innervation to the penis come from?
parasympathetic innervation comes from the sacral region
where does all the autonomic innervation converge on?
all converges on the pelvic plexus
what 2 things occur when the parasympathetic nervous system innervates to cause an erection?
1) stimulates the production of nitric oxide (NO, vasodilator) by deep arteries of the penis
2) deep arteries dilate and fill the lacunae in the corpora cavernosum
what 3 things occur when the sympathetic nervous system innervates to cause ejaculation?
1) stimulates the contraction of smooth muscle
2) stimulates reproductive ducts
3) stimulates accessory glands
what occurs when the somatic motor system innervates to cause ejaculation?
1) stimulates the contraction of skeletal muscle around the bulb of the penis
what does nitric oxide stimulate and support?
stimulates the vasodilation of the vessel to allow blood flow into the lacunae within the erectile tissues to support an erection
what 2 things does ejaculation combine?
1) spermatozoa
2) seminal fluid
what are the 4 processes that occur during the erection stage of the male sexual act?
1) parasympathetic response to stimuli
2) arteries in erectile tissue dilate
3) erectile tissue becomes engorged with blood
4) erect penis can be inserted into the vagina (intromission)
what are the 5 processes occur to cause an erection only in terms of the penis?
1) the deep artery dilates
2) trabecular muscle of erectile tissue relaxes
3) erectile tissues fill with blood
4) engorgement of erectile tissues
5) penis becomes erect
what does the bulbourethral gland secrete during an erection?
secretes bulbourethral fluid
what are the 3 processes that occur during the emission stage of the male sexual act?
1) sympathetic response
2) smooth muscle of the ductus deferens contracts to move sperm into the ampulla through peristaltic contractions
3) smooth muscle of the ampulla, seminal vesicles and the prostate gland contract moving sperm and seminal fluid into the urethra
what are the 4 processes that occur during the expulsion stage of the male sexual act?
1) semen in the urethra activates somatic and sympathetic reflexes
2) contractions of the urethral smooth muscles
3) pelvic floor muscles contract
4) semen is ejected
what are the 2 processes that occur during the resolution stage of the male sexual act?
1) blood flow to the penis is reduced
2) penis becomes flaccid
what are the 4 processes that occur to cause emission only in terms of the ductus deferens?
1) peristalsis
2) sperm moved into the ampulla
3) ampulla contracts
4) sperm moves into the urethra
what is the process that occurs to cause emission only in terms of the seminal vesicles?
seminal vesicles secrete components of seminal fluid
what is the process that occurs to cause emission only in terms of the prostate gland?
through efferent sympathetic signals the prostate gland secretes components of seminal fluid
what are the 2 processes that occur to cause expulsion only in terms of the accessory glands?
through efferent sympathetic signals the accessory gland:
1) additional secretion from the prostate gland and seminal vesicles
2) internal urethral sphincter contracts (urine remains in the bladder)
what are the 2 processes that occur to cause expulsion only in terms of the bulbospongiosus muscle?
through efferent somatic signals the bulbospongiosus muscle:
1) contracts and rhythmically compresses bulb/root of the penis, which compresses the urethra
2) semen is expelled
what are the 2 processes that occur to cause resolution only in terms of the internal pudendal artery?
through efferent sympathetic signals the internal pudenal artery:
1) constricts
2) reduces blood flow to penis
what are the 2 processes that occur to cause resolution only in terms of the trabecular muscles?
through efferent sympathetic signals the trabecular muscles:
1) contract
2) squeeze blood from the erectile tissues
what is the process that occurs to cause resolution only in terms of the penis?
through efferent sympathetic signals the penis:
1) become flaccid (detumescent)
what are 4 stages of the female sexual response?
1) the engorgement of the clitoris, labia and vagina in response to autonomic stimulation
2) lubricating fluid secreted through the vaginal wall; secretion of mucus into the vestibule through the greater vestibular glands
3) increased width and length of the vagina and the uterus elevates upwards
4) rhythmic contraction of vaginal, uterine and perineal (pelvic floor) muscles
what are the 5 things that occur in terms of fertilisation of the female sexual response?
1) semen is released into the upper part of the vagina (insemination) and sperm travels to the uterine tube for fertilisation at the ampulla
2) sperm fuses with the secondary oocyte
3) oocyte completes meiosis II
4) fertilised oocyte/ovum known as a zygote
5) zygote initiates cleavage (takes about 7 days) and travels towards the uterus for implantation
what is contraception?
any method used to prevent pregnancy that regulates when and how many pregnancies
what are the 2 contraception methods?
1) natural methods
2) artificial methods
what are 4 types of artificial methods of contraception?
1) barrier methods
2) hormonal contraceptives
3) intrauterine devices
4) sterilisation
what do natural methods of contraception rely on?
rely on timing of coitus or behaviour during coitus
what is the failure rate of natural methods of contraception?
high failure rate
what are the 2 natural methods of contraception?
1) rhythm method (periodic abstinence)
2) withdrawal method (coitus interruptus)
what is periodic abstinence associated with?
associated with trying to get pregnant
what is lactational infertility?
after a female has given birth and she is lactating
why is lactational infertility risky?
because the female is unaware of when her first ovulation will take place
what are the 2 barrier methods of artificial contraception?
1) caps or diaphragms that should be used in conjunction with spermicidal foams/jellies/creams/sponges
2) condoms
how long do barrier methods need to remain in after intercourse?
at least 6 hours
is the barrier method of caps and diaphragms common?
not commonly used anymore; preference for more effective and convenient methods
what are the 3 advantages of condoms?
1) cheap
2) readily available
3) easy to use
what do condoms reduce the risk of?
only contraceptive that reduces the risk of sexually transmitted infections (STIs)
what are the 2 steroidal contraceptives for females?
1) combined oral contraceptives pills
2) progestin-only contraception
what does the combined oral contraceptive pills contain?
contain estrogen and progestin
what does the combined oral contraceptive pills supress?
suppresses ovulation by preventing follicular development through affecting feedback loops to the hypothalamus and pituitary
what does the progesterone-only pill of progestin-only contraception contain?
contains low doses of progestin
what does the progesterone-only pill of progestin-only contraception effect?
effects the cervical mucus
what does the sub-dermal implant / injectable progestins act primarily on?
act primarily by disrupting follicular growth and ovulation
how long are sub-dermal implants / injectable progestins active for?
long acting over years
what are the 2 types of inter-uterine devices (IUD)?
1) copper IUD
2) hormonal IUD
what does IUD stand for?
inter-uterine device
what does a copper IUD cause?
causes a low grade inflammation
what does a copper IUD reduce?
reduces a sperm transport
what does a copper IUD cause to be toxic?
creates toxic oocytes and zygotes
what does a copper IUD impair?
impairs implantation
what does a hormonal IUD contain?
contains progestins
what does a hormonal IUD affect and reduces?
affects cervical mucus and reduces sperm transport
what does a hormonal IUD have local affects on?
local affects on the endometrium
what may a hormonal IUD prevent?
may prevent ovulation by thinning the endometrium so that it is not suitable for implantation
what is the sterilisation for females?
tubal ligation
what happens in tubal ligation?
the uterine tubes are cut
what is the sterilisation for males?
vasectomy
what happens in a vasectomy?
the vas (ductus) deferens is cut
what is the technical term for a male who can no longer acheive an erection?
erectile disfunction
true or false - an erection is a sympathetic response?
false
true or false - an ejaculation is a parasympathetic response?
false
true or false - the clitoris does not contain erectile tissue?
false
what is coitus interruptus?
withdrawal method (pullout)
