Aim: How does the reproductive system ensure the survival of the Human Species? Specialized system for males Specialized system for females Specialized cells –Sperm –Egg

Large intestine Rectum Seminal vesicle Prostate gland Bulbourethral gland Epididymis Testis Scrotum Penis Urethra Vas deferens Pubic bone Urinary bladder Male Reproductive System Section 39-3

Fallopian tube Ovary Urinary bladder Pubic bone Urethra Vagina Uterus Cervix Rectum Vagina Fallopian tube Ovary Female Reproductive System Section 39-3

The Menstrual Cycle Section 39-3

Fertilization (also called conception) in humans happens when the sperm cell reaches the egg cell and inserts its DNA into the egg cell.

Early stage of embryonic development Cleavage is the term used for the rapid division of cells that happens in the first hours after fertilization. There is little/no growth in the size of the zygote.

Gastrulation is the arrangement of cells into 3 distinct germ layers. Ectoderm Epidermis of skin Digestive system Nervous system Mesoderm Muscle Skeletal system Endoderm Organs Reproductive system

Human Embryonic Development

Comparison of external and internal development

Fetal Development: Ultrasound Pictures 1 Month2 Months3 Months 4 Months5 Months6 Months

Fetal Development: Ultrasound Pictures (Continued) 7 Months 8 Months At Birth

Critical Periods of Human Development

Embryonic Stem Cells The cell lines preserve their undifferentiated state and normal nuclei during subculture, however, they remain capable of differentiation into virtually any type of tissue.

Adult Stem Cells Current research is aimed at determining the mechanisms that underlie adult stem cell plasticity. If such mechanisms can be identified and controlled, existing stem cells from a healthy tissue might be induced to repopulate and repair a diseased tissue

Tissue Engineering-Other organs are being grown as we speak

Dolly the sheep was cloned