Week 12: Male Reproductive System Flashcards
what is the advantage to sexual reproduction?
genetic diversity
how do we get genetic diversity?
by mixing gene pools
- and getting genetic diversity gives us species more likely to survive
development of testes in utero starts with the testis up near?
the kidneys
the testes need to gradually move down and eventually move into?
the scrotum
what is that process called?
Descent of Testes
The testes are the most important organ of the male reproductive system because?
they produce the sperm
why are they not up near your lungs and surrounded by bone?
temperature control
to get optimal sperm production and healthy sperm that can swim and fertilize, the testes have to actually be at a temp that is?
slightly below body temp
- we wind up with very important reproductive organs that are not getting the same protection as other organs we consider to be very important in survival
as time passes, testes descend into the scrotum and the testes are connected to structures in the pelvic cavity by a group of structures called?
spermatic cords
one spermatic cord entering each cavity on each side of scrotum and in the spermatic cords we have?
artery, vein, lymphatics, nerve, and vas deferens (ductis deferens)
- all these things together are called the spermatic cords
they pass through a canal called?
inguinal canal
having the testis pass through that inguinal canal leaves a weak spot called?
inguinal hernia
if we get a tear in the inguinal canal, what happens?
intestine can get stuck or testis can get stuck
what are the layers of the scrotum?
skin on the outside, just deep to the skin we have some muscles (dartos muscle and cremaster muscle)
the dartos muscle is responsible for?
wrinkling the skin of the scrotum
why would you want to wrinkle the scrotum skin?
to be able to decrease surface area and less likely to lose heat
- part of temp regulation
the cremaster muscle has more of a protective function
- when the cremaster muscle contracts, the testis itself gets lifted up and the cremaster muscle will contract to bring testes closer to the body if temp is too low
- it will also contract if theres some sort of threat of injury to the testes.
the closer the testes are to the trunk of the body, the less..
likely they are to get injured
the testes are sitting in a pouch (each testis has its own pouch) and the testes move in that pouch and so we’re gonna have a serous membrane that helps?
line the scrotum and also cover the testis
what is that membrane called?
tunica vaginalis
where is the parietal and visceral layers of the tunica vaginalis located?
- the parietal layer is deep to the cremaster muscle
- the visceral layer sits just outside of the capsule around the testes
both of these layers produce a small amount of?
fluid that makes the testes in the scrotum a little more slippery
- decrease likelihood of damage from friction and if the testis is getting compressed, it slides more easily and it can hopefully slide out of the way of injury
just deep to the visceral layer of the tunica vaginalis, we have a structure called?
tunica albuginea
- a dense white connective tissue and it not only surrounds the testis but it also sends septa into the testis to divide into lobules
each testis is made up of somewhere around 200 lobules and in each lobule, we have somewhere around
1-3 seminferous tubules
the seminferous tubules are where the sperm are going to be?
produced and matured
how long is each seminferous tubule?
about 2 ft long
- 3 seminiferous tubule per lobule = 6 ft of seminferous tubules
- times 200 lobules=1200 ft of seminferous tubules
- times 2 testes = 2400 ft of seminferous tubules
why do we have 2400 ft of seminferous tubules ?
necessary for sperm production and sperm maturation
each of the seminferous tubules is gonna connect to a structure called?
rete testis