Puberty…how it happens?? Brain releases the hormone gonadotropin-releasing hormone (GnRH) This signals pituitary gland (just under the brain) to release Luteinizing hormone (LH) and follicle-stimulating hormone (FSH). These hormones act differently in girls and boys: In GIRLS: LH and FSH target the ovaries and stimulate the production of ESTROGEN. All three hormones prepare the body for pregnancy. In BOYS: LH and FSH target the testes and stimulate the production of TESTOSTERONE and sperm.

THE REPRODUCTIVE SYSTEM How much do you really know?

From the start…..  REPRODUCTION is the process by which organisms make more organisms like themselves.  In the human reproductive process, the GONADS— testicles in the males and ovaries in the females produce GAMETES, or sex cells.  The male gamete is called the SPERM  The female gamete is called the EGG or OVUM.  Eggs are released in a monthly cycle called OVULATION.

OVULATION and MENSTRUATION  OVULATION happens monthly when the ovary releases an egg into the FALLOPIAN TUBES.  The egg is pushed along by finger like structures called FIMBRIA.  If the egg is not fertilized—the egg dries up and leaves the body through the uterus. This process is called MENSTRUATION.  The blood and tissue from the inner lining of the uterus along with the remains of the egg create menstrual flow—also referred to as a “period”.

Female Reproductive Organs  The VULVA is the external portion of the female reproductive organs.  labia, clitoris, and vagina.  The VAGINA is the stretchable passage that connects a woman's internal and external sex organs.  Connects vulva with the cervix and uterus.  Birth canal  Passage for menstrual flow

2 million eggs at birth….down to 400,000 by adolescents Fallopian Tubes FEMALE REPRODUCTIVE ORGANS

And…On the inside The vagina connects to the UTERUS, a pear shaped cavity, at the CERVIX. The UTERUS has thick muscular walls—which can accommodate a growing fetus, and then help to push the baby out during labor. At each corner of the uterus, FALLOPIAN tubes connect to the OVARIES—which produce, store and release eggs (OVULATION).

Urethra Fimbria

THE MALE REPRODUCTIVE ORGANS  The male reproductive organs are also located both inside and outside of the body.  At sexual maturity, the TESTES, produce and store millions of sperm cells (GAMETES).  The testicles or testes, are also part of the endocrine system, which produces hormones.  TESTOSTERONE—causes deeper voices, muscle development, body and facial hair—and stimulates the production of SPERM.

From the inside…  The EPIDIDYMIS and VAS DEFERENS are part of the duct system which transport SEMEN—fluid that contains SPERM.  The SCROTUM—a sac like pouch stores the testicles outside the body to help maintain the temperature of the testicles.  The SEMINAL VESICLES and PROSTATE GLAND provide fluids (SEMEN) that lubricate the duct system and nourish sperm.

Vas Deferens Epididymis Seminal Vesicles & Prostate gland Vas Deferens

…and then?  When the male reaches a peak of sexual stimulation (ORGASM) he will EJACULATE.  SEMEN deposited near the female’s cervix— within 5 minutes can be in the fallopian tubes attempting to fertilize a released egg.  Sperm can survive up to 8 days—but typically only last 1-2 days.

Fertilization An egg can be fertilized up to 24 hours after ovulation. After being deposited in the vagina, sperm travel through the cervix and uterus. FERTILIZATION happens when the sperm meet the egg at the end of the fallopian tube.

Fertilization…and beyond The egg carries 23 chromosomes in its nucleus, surrounded by a soft shell, or membrane. The sperm, also carrying 23 chromosomes will break through the outer membrane. The two sets of chromosomes will be joined, forming a embryo. If the egg is fertilized it will attach to the thick wall of the uterus to receive blood and nutrients. After 9+ months, the developed fetus will be born.

Some Fertilization Facts!  It is the male that determines the gender of the fetus.  The ‘male’ sperm have longer tales—and can swim faster.  The ‘female’ sperm have shorter tales and are slower, but can live longer.  During ovulation, the acidity in the vagina is diminished—which actually allows and encourages sperm survival.

411-Teens and Parent talk Sex with Katie Couric 1. Based on their survey—what percentage of teens (15-16) are sexually active? 2. How do teens perceive the media and sex? 3. How common is oral sex—based on their survey—for year olds? 4. What percentage of kids thought oral sex was considered sex? 5. What does the counselor suggest are threats change the level of sexual maturity? 6. Compare how many parents think they talk often about sex…to the amount of kids that do? 7. What are some of the pieces of advice that the counselor suggested for parents when talking about sex with their kids? 8. What are parents worried most about in regards to teen’s sexual behaviors? 9. What are the outcomes of casual sex…as suggested by the counselor? 10. How did teens think their parents should talk about sex with them?