Chapter 14 Outline

Chapter 14: Early Human Development

Some distinctions of human development

• The Homo sapiens life cycle (very briefly)
• The specialized vocabulary for human embryology
• Further development: When does human life begin?
• Pregnancy and embryonic development
• Birth

Oogenesis and ovulation

• Oogenesis
• Ovulation
• Aneuploidy: When meiosis generates the wrong number of chromosomes

Fertilization, Cleavage, and Hatching

• Activation of the oocyte
• Cleavage

Implantation: The interplay of trophoblast and uterus

• Preparing the uterus for pregnancy
• Implantation
• The inflammation theory of implantation: Turning foes into allies

Gastrulation and the formation of extraembryonic tissues

• Preparing for gastrulation: Formation of the epiblast and amnion
• Gastrulation and the placenta
• Formation of the placenta
• Twinning

Infertility: Problems initiating development

• Circumventing infertility: In vitro fertilization

Developmental disorders: Genetic alterations

• The developmental nature of human syndromes
• Genetic and phenotypic heterogeneity

Environmental disruption of human development

• Alcohol as a teratogen
• Endocrine disruptors
• Endocrine disruptors and gametogenesis
• Transgenerational inheritance of developmental disorders

The role of chance in altering human development