Male Reproductive System Flashcards
What is a gamete?
A specialized sex cell that carries 23 chromosomes
What is sperm?
The male gamete
Where is sperm produced?
The testes
What are androgens?
Sex hormones in the male
What is the androgen that runs reproduction in the male?
Testosterone
Where are the testes?
In the scrotum (inferior to penis)
Why are the testes located in the scrotum?
To stay 2-4 degrees cooler than the rest of the body
Which muscles contract/relax to raise/lower the testes to keep them at a homeostatic temperature?
Dartos and cremaster
What is the glans penis?
The sensitive/erotic area of the penis
What is the purpose of the foreskin over the glans penis?
To protect against friction.
Why do some people get circumcised?
For religious reasons or to prevent infection
What is circumcision?
Cutting off the foreskin that covers the glans penis
What are the testicles separated by?
The scrotal septum
What does each teste have?
A spermatic cord
What do the spermatic cords have in them?
An artery, a vein, nerves, lymphatic drainage, and ductus deferens
What are ductus deferens for?
Ejaculation
What is another name for the testes?
The male gonads
What are the male gonads?
A pair of reproductive organs
What are the layers of the male gonads?
Tunica vaginalis and tunica albuginea
What is the tunica vaginalis?
The outer serous membrane of the male gonads
What is the Tunica albuginea?
Tough connective tissue that covers and separates the testes into 300-400 lobules
Where does sperm develop and travel?
Develops in the lobule, the sperm is tightly coiled, and travels through seminiferous tubules
When do the testes descend?
Around month 7 in the womb
What is cryptorchidism?
When the testes fail to descend before birth
What pushes the sperm cell to the epididymis?
Peristalsis
Where do the sperm cells go from the seminiferous lobules?
The head of the epididymis
Where do the sperm cells go from the head of the epididymis?
The body of the epididymus and then the tail
Where do the sperm cells wait for ejaculation?
The tail of the epididymis
What forces the sperm cells up the ductus deferens for ejaculation?
Strong muscular contractions
What is a vasectomy?
Blocking the ductus deferens so sperm cells can’t move through
What promotes sperm production?
Sertoli cells
What do sertoli cells do other than promote sperm production?
Eliminate germ cells and create the blood-testis barrier due to tight junctions
What is the stem/germ cell of the testes?
Spermatogonia
What is spermatogenisis?
The process of producing sperm in the seminiferous tubules
When does spermatogenesis begin?
During puberty
How long is 1 spermatogenesis cycle?
64 days
When does a new spermatogenesis cycle start and why?
Every 16 days because of the flow of testosterone
What do you get from 1 spermatogonia?
4 haploid daughter cells (spermatids)
What are spermatids?
The transition phase between spermatogonia and sperm cell
What part of the cell is a spermatid
The genetic information/the head of the sperm cell
How does spermatogonium divide?
Mitosis
How does the primary spermatocyte divide?
Meiosis I
How does the Secondary spermatocyte divide?
Meiosis II
How big is the sperm?
Smaller than most cells and 85,000 times less in volume than a female gamete
What are the 3 sections of the sperm?
Head, mid-piece, tail
What does the head of the sperm contain?
Haploid nucleus, a little cytoplasm, genetic information, and covered in lysosomal enzymes
What does the mid-piece of the sperm contain?
Tightly packed mitochondria that produced ATP so the sperm cell can move
What does the tail of the sperm cell contain?
Flagellum for movement/motility
What type of movement does the sperm tail have?
Back and forth movement to go from the male to female oocyte, circular movement when it finds the oocyte to dig into the oocyte wall
How many sperm cells are being produced per day?
100-300 million
How long does it take for sperm cells to move through epididymis?
12 days
What is the structure of the epididymis?
6 meters long and tightly coiled
What happens in the epididymis?
Sperm continue maturation and are moved by smooth muscle until the tail fully develops
Where does sperm go after the epididymis?
The ductus deferens
Where does the ductus deferens end?
The male ampulla
Where is the male ampulla?
Posterior to the bladder
How much do the seminal vesicles contribute to the semen volume?
60%
What does the seminal vesicles produce?
Fructose for ATP
Where does the fructose meet the sperm cells?
The ejaculatory duct
How big is the prostate gland?
The size of a walnut
Do women have a prostate gland?
No.
What does the prostate gland do?
Secrete fluid to coagulate the semen (which de-coagulates in the female)
Why does the prostate gland coagulate the semen?
As a protective coating for inside of the female because the vagina canal is too acidic for the sperm to survive
When does the prostate gland double in size?
During puberty
When does the prostate gland continue to gradually grow?
After age 25
What is prostate cancer?
The 2nd most common disease in men where the prostate gland continues to grow
What is benign prostatic hyperplasia?
When the prostate gets too big
What does benign prostatic hyperplasia cause?
The urge to urinate, weak stream of urine, and discomfort while urinating
What detects prostate cancer?
History, blood test, and rectal exam
What do the bulbourethral glands do?
Release thick and salty fluid to lubricate the end of the urethra and vagina, and clean urine residue
What is the last thing that add fluid to the semen?
The bulbourethral glands
When do the bulbourethral glands release fluid?
After arousal and before semen release
Can the fluid from the bulbourethral glands cause pregnancy?
Yes.
What does the penis have to undergo to ejaculate?
Vasocongestion
What does vasocongestion mean?
The blood vessels dilate and fill the chambers surrounding the urethra with blood to become and stay erect
What causes vasocongestion?
Nitric Oxide
What does Nitric Oxide (NO) do?
Dilates blood vessels and rapidly increases blood volume to fill chambers surrounding penis.
How many chambers surround the male urethra?
3 chambers
What prevents drainage of the venules?
Pressure of the filled chambers
What are the three chambers/caverns?
Corpora Cavernosa (2 superior), Corpus spongiosum (1 inferior)
What do the corpora cavernosa contain?
Arteries
Which cavern is right around the urethra?
Corpus spongiosum
What happens to the vein in the penis during erection?
It compresses so less blood can leave to maintain the erection.
What happens to the chambers and blood vessels during an erection?
The chambers fill with blood and the arteries grow and dilate
What is the purpose of an erection?
To get the semen as close to the cervix as possible so the sperm cells do not die in the acidic vaginal canal
When does testosterone begin secretion?
7 weeks after conception
What determines the difference between male and female sex?
The release of testosterone
What happens if no testosterone is release by the 7th week of development?
The baby will be a female.
Low levels of testosterone in a male lead to what?
Infertility
What else does testosterone help with in the male reproductive system (4 answers)?
Muscle development, bone growth, secondary sex characteristics, limbido (sex drive)
What secretes small amounts of testosterone?
The ovaries and adrenal glands
Where does the testosterone come from in week 7 of development?
The adrenal glands
What is testosterone controlled by?
The hypothalamus and pituitary gland
What comes from the hypothalamus that stimulates the pituitary gland?
Gonadotropin Releasing Hormone (GnRH)
What is released from the pituitary gland?
Luteinizing hormone (LH) and follicle-stimulation hormone (FSH)
What does Luteinizing hormone (LH) and follicle-stimulation hormone (FSH) both stimulate?
Testosterone and sperm production
What does just follicle-stimulation hormone (FSH) stimulate?
Spermatogenesis and the release of inhibin
What does inhibin do?
Tell the hypothalamus there is a high level of testosterone and sperm, stop production of Gonadotropin Releasing Hormone (GnRH), start producing Gonadotropin Inhibiting Hormone (GnIH)
What does just Luteinizing hormone (LH) stimulate?
The up-regulation of testosterone
