Lecture 38: Coitus, Fertilisation and Contraception Flashcards
What two events occur during coitus?
intromission and insemination
Define intromission
when the erect penis is introduced into the vagina
Define insemination
the semen is released into the upper pat of the vagina so that the sperm can travel to the appropriate site for fertilisation
What is the purpose of coitus?
to ensure the male gamete can be transported to the female reproductive tract
What determines whether the spermatozoa can go into the external os, internal os into the uterus and up into the ampulla?
the stage of the menstrual cycle and the consistency of the mucus
What must happen in order to allow for intromission?
an erection
What is an erection associated with in terms of secretion? Where is this coming from and what is its purpose?
mucous secretion for the bulbourethral glands to provide lubrication for the urethra and clearing out any residual urine that might be present
What follows erection?
ejactulation
What are the two phases of ejaculation?
emission
expulsion
What occurs in ejaculation?
transporting sperm into the urethra and getting the accessory glands to secrete the seminal fluids which can be ejaculated by urethra
What occurs after ejaculation?
resolution
What are the lacunae and where are they?
The spaces where blood can fill in the corpus cavernosum to engorge the tissues
What is the bulbospongiosis muscle?
encases the root and is important in ejaculation
The erectile tissues are surrounded by different layer of
fascia
What are fascia?
layers of connective tissue
What are lacunae of the corpus cavernosa surrounded by?
trabeculae
What are trabeculae?
connective tissue containing smooth muscle which are important for constraining and allowing the blood to cause the engorgement of the tissues
Venules form a venous plexus around the
outside of the erectile tissues
What are the columns of erectile tissue surrounded and supported by?
various layers of fascia
What fascia surrounds the corpora cavernosa?
tunica alberginia
Apart from being around the corpora cavernosa, where is the other tunica alberginia?
around the corpus spongiosum
What fascia surrounds the two tunica alberginia?
the deep/Buck’s fascia
What fascia surrounds the the deep/Buck’s fascia?
the superficial facia
What is the purpose of the fascia?
restraining the erection so that when the erectile tissues fill with blood, they put pressure back against the fascia to support the erection
Why is the tunica alberginia around the corpus spongiosum not as dense as the one around the corpora cavernosa?
because we don’t want the urethra to be blocked during ejaculation so it prevents the engorgement being sufficient to block the urethra
What are deep to the labia manora?
the bulbs of vestibule
The glans, the body and the crus of the clitoris are homologous to what in the penis?
copora cavernosa