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

MaleReproductive System

Section 39-3

Fallopian tube

Ovary

Urinary bladder

Pubic bone

Urethra

Vagina

Uterus

Cervix

Rectum Vagina

Fallopian tube

Ovary

FemaleReproductive SystemSection 39-3

The Menstrual CycleSection 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 24-48 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 Month 2 Months 3 Months

4 Months 5 Months 6 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