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

Scrotum Controls temperature of testicles

Testicles Also called testes Produce millions of tiny sperm cells and sex hormones

Sperm Cell Males produce millions of sperm cells every day Each sperm is 1/600 of an inch.

Testosterone Produced in testes Male sex hormone Small amounts found in females

Knowledge Check Q1: What structure regulates the temperature of the testes? A: scrotum Q2: Where are sperm and hormones made? A: testicles Q3: What is the male sex hormone? A: testosterone

Urethra passageway for both urine and semen Semen is a mix of fluids that help sperm swim A male cannot urinate and ejaculate at the same time

Penis Functions in urination, sex and reproduction

Foreskin The fold of skin at the end of the penis covering the glans, or the head of the penis.

Knowledge Check Q4: What are the functions of the penis? A: urination, sex and reproduction Q5: What is the name of the skin that covers the tip of the penis? A: foreskin Q6: What is the mixture of sperm cells and fluids? A: semen Q7: What is the passageway for semen and urine? A: urethra

Circumcision The removal of the foreskin from the penis Performed for religious, hygienic, or cultural reasons.

Erection Penis is made of spongy erectile tissue that expands and contracts Erection occurs penis fills with blood and becomes stiff and hard

Ejaculation Muscles around the reproductive organs contract and semen is released from body Also known as an orgasm Each time a male ejaculates, it can contain up to 500 million sperm.

Knowledge Check Q8: What term describes when the penis fills with blood and gets longer and harder? A: erection Q9: What term describes the removal of foreskin? A: circumcision Q10: What is another term for ejaculation? A: orgasm

Identify the Parts Q11 Q12 Q13