Human Reproduction

Review Both males and females produce specialized sex cells called “gametes.” Both males and females produce specialized sex cells called “gametes.” Each gamete contains ½ of the genetic information to form a new individual. Each gamete contains ½ of the genetic information to form a new individual. Fertilization: Joining of egg and sperm. Fertilization: Joining of egg and sperm.

The Male Reproductive System Main function: produce and deliver sperm Main function: produce and deliver sperm A sexually mature human male, produces millions each day. A sexually mature human male, produces millions each day. Sperm are produced in the testes by meiosis (spermatogenesis). Sperm are produced in the testes by meiosis (spermatogenesis). Review (meiosis) Review (meiosis)

Structure of Sperm Tail- used for locomotion. Tail- used for locomotion. Midsection- contains mitochondria. Why? Midsection- contains mitochondria. Why? Head- holds chromosomes and digestive enzymes which allow sperm to penetrate into the egg. Head- holds chromosomes and digestive enzymes which allow sperm to penetrate into the egg.

Male testicle has seminiferous tubules where sperm and a fluid that nourishes sperm is made

The “Pathway” of Sperm Penis Urethra Testes Epididymis (sperm storage) Vas Deferens from scrotum to urethra Bulbourethral Gland Seminal VesicleProstate Gland Sperm produced here

The “Pathway” of Sperm 1. Testes (formation) 2. Stored and nourished in epididymis 3. Vas deferens 4. Pick up fluids in three glands -Seminal vesicles provide fluid that “nourishes” sperm. - Bulbourethral gland and prostate gland create a fluid that makes sperm resistant to acid. 5. Urethra 6. Ejaculation (tube to bladder is blocked off by a valve) **Sperm + Glandular secretions = SEMEN.

Female Reproductive Role The females reproductive role is to: 1.) Make and release eggs. 2.) Nourish the developing fetus.

Female Anatomy Urethra Ovary Uterus Cervix Bladder Fallopian Tube Fertilization occurs here Egg formation

“The Menstrual Cycle” Eggs begin to mature in ovaries before a female is born. All the eggs remain immature until puberty. Each egg develops inside a “follicle.” Usually only one egg makes it to maturity each month.

“The Menstrual Cycle” Ovulation: egg bursts out of the follicle and is released, moving through fallopian tube, where it may be fertilized. The uterus must be ready to accept a fertilized egg. Different hormones help to control the menstrual cycle.

Female Hormones 1.) FSH (Follicle stimulating hormone) - Causes follicles to mature. 2.) LH (Leutinizing hormone) - LH causes at least one follicle to burst open— OVULATION

Birth Control 1.) Physical forms - Condoms block the sperm from getting to egg. 2.) Chemical forms - “The pill.” Prevents release of FSH and LH. - Result = No ovulation. Normal menstrual cycle proceeds.

Fertilization and Development Zygote- Newly fertilized egg. Once it begins to divide, it is called an embryo. Embryo must “implant” itself into the uterine wall.

The Placenta Transports materials back and forth to the embryo.  Oxygen – Carbon dioxide  Nutrients (carb’s, protein, fat)  Urea (liquid, cellular waste)  Antibodies

Maternal Health The health of the baby depends on the health and activities of the mother. Smoking, drugs, alcohol, radiation, and pathogens can all harm the fetus. Spina bifida

Trimesters Pregnancy is divided into 3, three month segments called “trimesters.” 1 st- All vital organs are formed 2 nd –Circulatory system functioning 3 rd – Eyes open

Stopping of the Menstrual Cycle Between ages 45 – 55 ovulation and menstruation stop. The shut down of ovarian and uterine cycles is known as menopause.