Male reproductive system Flashcards
What 5 structures are in the male reproductive system
Scrotum
Testes
Accessory glands
Male reproductive system ducts
Penis
What is the scrotum
Deeply pigmented skin, fibrous tissue and muscles.
Internally divided by 2 sacs, each contains a testi, one epididymis and the testicular end of the spermatic cord.
What regulates the temperature of the scrotum
The contraction of its muscles and the location of the scrotum
What temperature is needed for sperm production
2-3 degrees below core body temperature
Because the scrotum is outside the body, this temperature is maintained.
In colder temperatures, what muscles contract in the scrotum to move the testes closer so that they absorb body heat.
Cremaster muscle
Dartos muscle
What does the darts muscle in the scrotum do
Helps move testi closer to body to absorb body heat
Causes scrotum to wrinkle, which reduces heat loss
What do the testes do
Produce sperm
During foetal development what happens to the testis
They are originally formed just below the kidneys in the abdomen, and then gradually descend to the scrotum shortly before or after birth.
What is the serous membrane the covers the testis called
Tunica vaginalis
What fibrous layer of tissue forms the septa, which divide testis into 200-300 sections or lobes
Tunica albuginea
Each of the 200 lobes of the septa contain 3 narrow long coiled tubules called what?
Semniferous tubules
What two types of cell do the seminiferous tubules contain.
Spermatogenic cells (sperm forming cells)
Sertoli cells (Spermatogenic supporting cells)
What cells are found between the seminiferous tubules
Leydig cells
What do leydig cells do
They secrete the male sex hormone, testosterone, promotes development off manly features and promotes sex drive.
What is spermatogenesis
Term used for production of sperm
What is spermatogenesis
Term used for production of sperm
How much sperm is produced a day
300 million
How long does it take a single sperm to develop
10 weeks
How long is a sperm
0.05mm long
How many chromosomes are found in the head and nucleus of the sperm
23
The head of the sperm is covered in acrosome, what does this do?
Enyzmes that help the sperm to penetrate the ovum of the female during fertilisation.
What type of environment does the sperm need in order to survive?
An alkaline environment.
What percent of semen is sperm
Less than 1%
What is the prostate gland
Found at the base of bladder and surround the urethra.
The gland produces a milky alkaline secretion that contributes to the volume of semen.
What are the bulbo-urethral glands
A pair of glands situated on each side of the urethra. They produce a few drops of fluid upon sexual arousal, which act as lubricant.
They also neutralise the acidity of the urethra prior to ejaculation/.
What are seminal vesicles
Pair of glands close to the prostate gland on either side of the bladder.
Produce 60% of semen volume
The fluid produced provides nourishment and fuel for sperm.
The duct system through which the sperms pass after leaving the testis to reach the exterior of the body consists of what 4 ducts
Epididymis
Ductus deferens
Ejaculatory duct
Urethra
What is the epididymis
Single coiled tube that acts as a reservoir of sperms at their exit from the testis.
What is the Ductus deferens
A thin muscular tube that transmits the sperms the ejaculatory duct
What is the urethra
A single tube that begins in the bladder
What both urine and semen pass through
Is about 15cm long
In the shaft of the penis there are three parallel cylindrical masses of tissue called what
Tunica albuginea
