From Boy to Man:From Boy to Man:Male ReproductionMale Reproduction

When a baby boy is born, he has all the parts of his When a baby boy is born, he has all the parts of his reproductive system in place, but it isn't until puberty that reproductive system in place, but it isn't until puberty that he is able to reproduce. he is able to reproduce.

Reproductive SystemReproductive System

ScrotumScrotum

The The scrotumscrotum is a thin, but is a thin, but muscular, sac of skin that muscular, sac of skin that hangs below the boy’s hangs below the boy’s body. body. This sac of skin This sac of skin helps to regulate the helps to regulate the temperature of testiclestemperature of testicles, , which need to be kept 1 ½ which need to be kept 1 ½ to 2 degrees cooler than to 2 degrees cooler than body temperature to body temperature to produce sperm. produce sperm.

Testicles and TestosteroneTesticles and Testosterone

Inside the scrotum, are Inside the scrotum, are the two the two testiclestesticles, also , also called called testestestes, which , which produce the millions of produce the millions of tiny sperm cellstiny sperm cells. They . They are oval-shaped and are oval-shaped and grow to about 2 inches. grow to about 2 inches. The testicles also The testicles also produce hormonesproduce hormones, , including including testosterone.testosterone.

Sperm CellSperm Cell

A male who has A male who has reached puberty will reached puberty will produce millions of produce millions of sperm cells every sperm cells every day. Each sperm is day. Each sperm is extremely small: only extremely small: only 1/600 of an inch. 1/600 of an inch.

Seminiferous TubulesSeminiferous Tubules

Sperm develop in the testicles within Sperm develop in the testicles within a system of a system of tiny tubes called the tiny tubes called the seminiferous tubulesseminiferous tubules. These . These tubules contain simple round cells that transform tubules contain simple round cells that transform into sperm cells during puberty.into sperm cells during puberty.

Knowledge CheckKnowledge Check

Q: What is the main function of the scrotum?Q: What is the main function of the scrotum?

A: to regulate the temperature of the testesA: to regulate the temperature of the testes

Q: What is produced in the testes?Q: What is produced in the testes?

A: sperm and hormonesA: sperm and hormones

Q: What are the seminiferous tubules?Q: What are the seminiferous tubules?

A: the coiled network of tubules inside the A: the coiled network of tubules inside the testestestes

EpididymisEpididymis

The sperm complete their development in the The sperm complete their development in the epididymisepididymis, which is a comma-shaped structure , which is a comma-shaped structure that sits along the upper back side of each that sits along the upper back side of each testicle. It takes sperm about 4 to 6 weeks to testicle. It takes sperm about 4 to 6 weeks to travel through the epididymis while it matures. travel through the epididymis while it matures.

Vas DeferensVas Deferens

Once the sperm mature, Once the sperm mature, the the vas deferens, vas deferens, a a musculamuscularr tube, tube, carries the carries the sperm from the sperm from the epididymis up to the epididymis up to the ejaculatory ductejaculatory duct where it where it will be mixed with fluids will be mixed with fluids and released from the and released from the body. body.

Ejaculatory DuctEjaculatory Duct

The The ejaculatory ductejaculatory duct is a short, straight is a short, straight tube that is formed by tube that is formed by the vas deferens tube the vas deferens tube and the seminal and the seminal vesicle and leads into vesicle and leads into the prostate gland. the prostate gland. This is where the This is where the sperm will wait to be sperm will wait to be ejaculated from the ejaculated from the body.body.

Knowledge CheckKnowledge CheckQ: Why do the sperm stay in the epididymis?Q: Why do the sperm stay in the epididymis?

A: to complete their development A: to complete their development

Q: What is the function of the vas deferens?Q: What is the function of the vas deferens?

A: to carry sperm from the epididymis to the A: to carry sperm from the epididymis to the ejaculatory ductejaculatory duct

Q: What happens to the sperm in the Q: What happens to the sperm in the ejaculatory duct?ejaculatory duct?

A: they wait to be ejaculatedA: they wait to be ejaculated

SemenSemen

There are several There are several glands that provide glands that provide fluids that mix with the fluids that mix with the sperm and help it to sperm and help it to move through the move through the system. system. This mixture This mixture of sperm cells and of sperm cells and fluids is called fluids is called semensemen..

Seminal VesiclesSeminal Vesicles

The The seminal seminal vesiclesvesicles are sac-like are sac-like structures attached to structures attached to the vas deferens. the vas deferens. They add a sugary They add a sugary fluid that nourishes fluid that nourishes the sperm cells and the sperm cells and gives them energy.gives them energy.

Prostate GlandProstate GlandThe The prostate glandprostate gland surrounds the surrounds the ejaculatory duct just ejaculatory duct just below the bladder. It below the bladder. It releases a chemical releases a chemical alkaline fluid into the alkaline fluid into the urethra to neutralize the urethra to neutralize the acidsacids that are left behind that are left behind in the urethra after a in the urethra after a male urinates. male urinates.

The prostate gland is also a The prostate gland is also a common site of cancer in older common site of cancer in older males.males.

Cowper’s GlandsCowper’s Glands

Beneath the prostate gland is Beneath the prostate gland is a small, pea-sized gland a small, pea-sized gland called the called the cowper’s glandcowper’s gland. . ItIt releases a lubricating fluid releases a lubricating fluid that helps give the sperm that helps give the sperm more mobilitymore mobility. It is also . It is also called a pre-ejaculatory fluid called a pre-ejaculatory fluid and is present during an and is present during an erection. erection.

This fluid can contain thousands of sperm cells that could get a female pregnant even if the male does not ejaculate.

Knowledge CheckKnowledge Check

Q: What is the mixture of sperm and fluids Q: What is the mixture of sperm and fluids called?called?

A: semenA: semen

Q: What is the purpose of the sugary fluid?Q: What is the purpose of the sugary fluid?

A: to give energy to the spermA: to give energy to the sperm

Q: What is the purpose of the prostate fluid?Q: What is the purpose of the prostate fluid?

A: to neutralize acid in the urethraA: to neutralize acid in the urethra

UrethraUrethra

The The urethraurethra is the tube is the tube that extends from the that extends from the bladder to the outside of bladder to the outside of the body through the the body through the penis and is a penis and is a passageway for both urine passageway for both urine and semenand semen. While a male . While a male can urinate and ejaculate, can urinate and ejaculate, he cannot do them both at he cannot do them both at the same time. the same time.

PenisPenisThe The penispenis is actually made up of two parts: the is actually made up of two parts: the shaft,shaft, which is the main part of the penis, and the which is the main part of the penis, and the glansglans, which is the tip. , which is the tip. Its main functions are Its main functions are urination, sexual intercourse and reproductionurination, sexual intercourse and reproduction..

ForeskinForeskin

The fold of skin at the end of the penis covering The fold of skin at the end of the penis covering the glans the glans is known as foreskin.is known as foreskin.

CircumcisionCircumcision

The removal of the foreskin from the penis The removal of the foreskin from the penis is called a is called a circumcision. It is usually done for religious, hygienic, or circumcision. It is usually done for religious, hygienic, or cultural reasons.cultural reasons.

ErectionErection

The inside of the penis is The inside of the penis is made of a spongy erectile made of a spongy erectile tissue that can expand and tissue that can expand and contract.contract.

When a male is sexually When a male is sexually excited, excited, the tissue in the the tissue in the penis fills with blood and it penis fills with blood and it becomes stiff and hardbecomes stiff and hard..

EjaculationEjaculation

When muscles around When muscles around the reproductive the reproductive organs contract and organs contract and force the semen out of force the semen out of the male's body the male's body through his urethra — through his urethra — this process is called this process is called ejaculation, ejaculation, also also known as an known as an orgasmorgasm.. Each time a male

ejaculates, it can contain up to 500 million sperm.

Knowledge CheckKnowledge Check

Q: What is the function of the urethra?Q: What is the function of the urethra?

A: it is a passageway for urine and semenA: it is a passageway for urine and semen

Q: What term describes the removal of Q: What term describes the removal of foreskin?foreskin?

A: circumcisionA: circumcision

Q: What is another term for ejaculation?Q: What is another term for ejaculation?

A: orgasmA: orgasm

1.Cowper’s gland adds lubricating fluid; also a pre ejaculatory fluid that contains enough sperm to get a female pregnant even without ejaculation.

2. Scrotum regulates the temperature of the testicles and keeps them several degrees below body temperature.

3. Testicles produces sperm and testosterone.

4. Penis functions in urination, sexual intercourse and reproduction.

5. Vas deferens transports sperm from the epididymis to the ejaculatory duct.

6. Seminal vesicle adds sugary fluid to give energy to the sperm cells.

7. Prostate gland adds chemical alkaline fluid to neutralize acid in the urethra; also a common site of cancer in males.

8. Ejaculatory duct where sperm wait to be ejaculated.

9. Urethra passageway for urine and semen.

10. Epididymis stores sperm until they mature.

11.Circumcision the removal of the skin covering the tip of the penis

12. Seminiferous tubules coiled network of tubules inside each testicle

13. Foreskin the fold of skin covering the tip of the penis

14. Testosterone the male sex hormone

15. Ejaculation the sudden release of semen from an erect penis (orgasm)

16. Erection when the penis fills with blood and becomes longer and harder

17. Semen the mixture of fluids that carry sperm

Label the DiagramLabel the Diagram