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Male Reproductive System


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Male Reproductive System
The male reproductive system mostly exists outside of your body. The external organs include the penis, scrotum, and testicles. Internal organs include the vas deferens, prostate, and urethra. The male reproductive system is responsible for sexual function and urination.

What does the male reproductive system do?
The organs that make up the male reproductive system perform the following:
Produce, maintain, and transport sperm cells and semen. Sperm cells are male reproductive cells. Semen is the protective fluid around sperm.
▪️Discharge sperm.
produce and secrete male sex hormones.

How does the male reproductive system function?
The entire male reproductive system depends on hormones. Hormones are chemicals that stimulate or regulate activity in your cells or organs. The primary hormones that help the male reproductive system function include:

▪️ Follicle-stimulating hormone (FSH) Your pituitary gland makes
FSH. FSH is necessary to produce sperm (spermatogenesis).
▪️Luteinizing hormone (LH). Your pituitary gland also makes LH. LH is necessary to continue the process of spermatogenesis.
▪️Testosterone. Testosterone is the main sex hormone in people. It helps you develop certain characteristics, including muscle mass and strength, fat distribution, bone mass, and sex drive (libido).

What are the external parts of the male reproductive system?
Most of the male reproductive system is on the outside of your abdominal cavity or pelvis. The external body parts of the male reproductive system include the penis, scrotum, and testicles. Another name for these parts is genitals or genitalia.

Penis
The penis is the male organ for sexual intercourse. It contains many sensitive nerve endings, and it has three parts:
▪️Root. The root is the base of your penis. It attaches to the wall of your abdomen.
▪️Body (shaft). The body has a shape like a tube or cylinder. It consists of three internal chambers: the two larger chambers are the corpora cavernosa, and the third chamber is the corpus spongiosum. The corpora cavernosa runs side by side, while the corpus spongiosum surrounds your urethra. There’s a special, sponge-like erectile tissue inside these chambers. The erectile tissue contains thousands of spaces. During sexual arousal, the spaces fill with blood, and your penis becomes hard and rigid (erection). An erection allows you to have penetrative sex. The skin of the penis is loose and stretchy, which lets it change size when you have an erection.
▪️Glans (head). The glans are the cone-shaped tips of the penis. A loose layer of skin (foreskin) covers the glans. Healthcare providers sometimes surgically remove the foreskin (circumcision).
In most people, the opening of the urethra is at the tip of the glans. The urethra transports pee and semen out of your body. Semen contains sperm. You expel (ejaculate) semen through the end of your penis when you reach sexual climax (orgasm).

When your penis is erect, your corpora cavernosa presses against the part of your urethra where pee flows. This blocks your pee flow so that only semen ejaculates when you orgasm.

Scrotum
The scrotum is the loose, pouch-like sac of skin that hangs behind the penis. It holds the testicles (testes) as well as nerves and blood vessels.

The scrotum protects your testicles and provides a sort of “climate-control system.” For normal sperm development, the testes must be at a temperature that’s slightly cooler than body temperature (between 97 and 99 degrees Fahrenheit or 36 and 37 degrees Celsius). Special muscles in the wall of the scrotum let it contract (tighten) and relax. Your scrotum contracts to move your testicles closer to your body for warmth and protection. It relaxes your body to cool them.

Testicles
The testicles (testes) are oval-shaped organs that lie in your scrotum. They’re about the size of two large olives. The spermatic cord holds the testicles in place and supplies them with blood. Most people with AMAB have two testicles, on the left and right sides of the scrotum. The testicles make testosterone and produce sperm. Within the testicles are coiled masses of tubes. These are the seminiferous tubules. The seminiferous tubules produce sperm cells through spermatogenesis.

Epididymis
The epididymis is a long, coiled tube that rests on the back of each testicle. It carries and stores the sperm cells that your testicles create. The epididymis also brings the sperm to maturity; the sperm that emerge from the testicles are immature and incapable of fertilization. During sexual arousal, muscle contractions force the sperm into the vas deferens.

What are the internal parts of the male reproductive system?
There are several internal (accessory) organs in the male reproductive system. They include:
▪️Vas deferens
The vas deferens is a long, muscular tube that travels from the epididymis into the pelvic cavity, just behind the urinary bladder. The vas deferens transports mature sperm to the urethra in preparation for ejaculation.

▪️Ejaculatory ducts
Each testicle has a vas deferens that joins with seminal vesicle ducts to form ejaculatory ducts. The ejaculatory ducts move through your prostate, where they collect fluid to add to semen. They empty into your urethra.

▪️Urethra
The urethra is the tube that carries pee from your bladder outside of your body. If you have a penis, it also ejaculates semen when you reach orgasm.

▪️Seminal vesicles
The seminal vesicles are sac-like pouches that attach to the vas deferens near the base of the bladder. Seminal vesicles make up to 80% of your ejaculatory fluid, including fructose. Fructose is an energy source for sperm and helps them move (motility).

▪️Prostate gland
The prostate is a walnut-sized gland that rests below your bladder, in front of your rectum. The prostate adds additional fluid to ejaculate, which helps nourish sperm. The urethra runs through the center of the prostate gland.

▪️Bulbourethral (Cowper) glands
The bulbourethral glands are pea-sized structures on the sides of your urethra, just below your prostate. They create a clear, slippery fluid that empties directly into the urethra. This fluid lubricates the urethra and neutralizes any acids that may remain from your pee.