Flashcards in Male Reproductive System Deck (36)
What are the secondary sex characteristics in males?
broad shoulders, deep voice, increased muscle size and bone density, and increased hair
What hormone is produced by the male reproductive system? What gland stimulates the production of this hormone and when?
testosterone- This begins during puberty in a male when the anterior pituitary gland secretes luteinizing hormone. Testosterone stimulates the sex drive and growth in males.
What are the organs of the male reproductive system ?
the testes, the epididymis, vas deferens, seminal vesicles, prostate gland, bulbourethral glands, urethra and penis
What are the male gonads? What is their purpose and where are they located ?
The testes produce sperm and testosterone and are suspended within the scrotum sac.
What cells produce testosterone?
Interstitial cells located in the connective tissue of the testes
What is the site of sperm production?
The seminiferous tubules located in the lobules of the testes
Where do sperm mature after being produced? How long do they stay there?
In the epididymis. It takes about 20 days. Once mature, they remain until expelled to the outside of the body.
How do the testes develop?
Their development begins inside the abdominal cavity but they descend into the scrotal sacs as development proceeds.
What complication can result if the testes do not descend into the scrotal sacs? Why is this?
Sterility (the inability to produce offspring) results if the testes do not descend or the male does not receive hormone therapy or undergo surgery to place the testes in the scrotum.
Sperm production is inhibited at body temperature; a cooler temperature is required, hence the testes are inside the scrotum outside of the main body.
What are the structures of the duct system in the male reproductive system?
The duct system contains the accessory organs of the male reproductive system,
-vas deferens (or ductus deferens)
- the urethra.
The duct system provides a place for sperm to mature and then sperm are expelled from the body at the appropriate time.
What is the vas Deferens?
Once the sperm are mature, they are propelled into this structure by muscular contractions.
- The vas deferens travels superiorly though the inguinal canal and then turns posteriorly over the bladder and finally descends inferiorly to the base of the prostate gland where it connects with the duct of the seminal vesicle to form the ejaculatory duct.
What does the ejaculatory duct connect with ? Why?
The urethra. So sperm can exit the body
What is the spermatic cord?
The spermatic cord is the cord-like structure in males formed by the vas deferens (ductus deferens) and surrounding tissue that runs from the deep inguinal ring down to each testicle. The spermatic cord holds the scrotum in place.
What is a vasectomy?
The cutting of the vas deferens which prevents sperm from exiting the body to fertilize an egg. This results in sterility although testosterone production unaffected.
When sexually aroused, what action does the vas deferens take?
The smooth muscles of the vas deferens cotnract and sperm enter the uretha.
The urethra has functions in which 2 body systems?
the male reproductive and urinary systems It functions to transport both sperm and urine to the outside of the body but only one of these functions can occur at a given time.
What are the 3 regions of the urethra? Where does the urethra travel from?
prostatic urethra, membranous urethra, and spongy urethra.
-The prostatic urethra is surrounded by the prostate gland.
- The membranous urethra begins at the end of the prostatic urethra and travels to the penis.
-The spongy urethra runs through the penis and opens to the outside at the external orifice.
The urethra travels from the bladder through the penis.
What structures in the penis enable it to become erect?
Spongy, erectile tissue containing distensible blood spaces extends through the shaft of the penis. During sexual arousal, nervous system reflexes cause an increase in arterial blood flow to the penis. This fills the blood spaces in the erectile tissue and enable erection.
Two sections of the penis ....
the shaft is the cylindrical part of the penis and the glans penis is the enlarged end.
Since sperm need to be produced at a temperature lower than body temperature, how does the scrotum, which holds the testes outside the body, adjust to outside temperature?
The skin of the scrotum can adjust to outside temperature, contracting when outside temperatures are cold, allowing the sperm to get some heat from the body and expanding when temperatures are warm to keep sperm away from the higher body temperature.
What is semen? What glands contribute to its makeup?
A thick, whitish fluid that contains sperm and accessory gland secretions from the seminal vesicles, the prostate and the bulbourethral glands.
What are the seminal vesicles?
An accessory gland that contributes to semen's makeup.
The paired seminal vesicles lie at the base of the bladder where they each join with a vas deferens to form an ejaculatory duct that enters the urethra. As sperm pass from the vas deferens into the urethra, the seminal vesicles secrete a thick, viscous fluid containing nutrients (fructose, vitamin C, and prostaglandins (facilitates movement) for possible use by the sperm
What are some components of semen?
Some of the components of the semen are fructose (fuel), prostaglandins (facilitates movement), relaxin (enhances motility), alkaline pH (protective and motility enhancement) and the antibiotic seminalplasmin (kills bacteria). About 200 to 500 million sperm are expelled from the penis into the vagina during ejaculation.
What is the prostate gland? What problems can arise with the prostate in older men?
Just below the bladder is the prostate gland, which secretes a milky alkaline fluid believed to activate or increase the motility of the sperm. In older men, the prostate gland may become enlarged, thereby constricting the urethra and making urination slow or difficult.
What are the bulbourethral glands?
They are accessory glands that secrete a lubricating mucus to clear the urethra of urine before semen is ejaculated. Since urine is acidic, it can be detrimental to sperms activity.
The urethra performs 2 duties that cannot happen at the same time...
Carries urine from the bladder during urination.
Secretes sperm through ejaculation
What is spermatogenesis? How long does it take? In what stage of life does it begin? Do men ever stop producing sperm?
The production of sperm. 64-72 days. It begins at the onset of puberty. Men produce sperm throughout their lifetime.
What are spermatogonia?
Stem cells from which sperm are formed. These stem cells undergo mitotic divisions at birth until puberty.
What is the role of follicle stimulating hormone in males?
Secreted by the anterior pituitary gland at the onset of puberty, once secreted the spermatogonia undergo cell division; one of the cells continues the stem cell line. The other cell, known as the primary spermatocyte, undergoes meiosis.