Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Fundamentals of Anatomy & Physiology SIXTH EDITION Frederic H. Martini PowerPoint ® Lecture Slide Presentation prepared by Dr. Kathleen A. Ireland, Biology Instructor, Seabury Hall, Maui, Hawaii Chapter 29, part 1 Development and Inheritance

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Learning Objectives Explain the relationship between differentiation and development and specify the various stages of development Describe the process of fertilization List the three prenatal periods and describe the major events associated with each Discuss the importance of the placenta as an endocrine organ

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Learning Objectives Discuss the structural and functional changes in the uterus during gestation List and discuss the events that occur during labor and delivery Relate basic principles of genetics to the inheritance of human traits

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings SECTION 29-1 An Overview of Topics in Development

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Development Gradual modification of physical and physiological characteristics Differentiation The creation of different types of cells Differentiation and development

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Prenatal development Embryological Changes occurring the first two months after fertilization Fetal Begins at the start of the ninth week and continues until birth Postnatal development Commences at birth and continues to maturity Stages of development

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings SECTION 29-2 Fertilization

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Occurs in the uterine tubes Within a day of ovulation Spermatozoa cannot fertilize an ovum until after capacitation Fertilization (conception)

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 29.1 Fertilization Figure 29.1a

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 29.1 Fertilization Figure 29.1b

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Oocyte is in meiosis II Surrounded by the corona radiate Spermatozoa release hyaluronidase and acrosin Enzymes required to penetrate corona radiate Single spermatozoan contacts oocyte, fertilization begins Oocyte activation The Oocyte at Ovulation Animation: Fertilization and Oocyte Activation PLAY

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Oocyte completes meiosis II Functionally mature ovum Female pronucleus and male pronucleus fuse (amphimixis) Polyspermy prevented by membrane depolarization and cortical reaction Oocyte activation

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings SECTION 29-3 The Stages of Prenatal Development

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Induction During prenatal development differences in cytoplasmic composition trigger changes in genetic activity Gestation periods Three trimesters Embryonic and Fetal Periods

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings SECTION 29-4 The First Trimester

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Cleavage Zygote becomes a preembryo then a blastocyst Implantation Blastocyst burrows into uterine endometrium Placentation Blood vessels form around blastocyst and placenta develops Embryogenesis Formation of a viable embryo The First Trimester

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings A series of cell divisions that subdivides the cytoplasm of the zygote Trophoblast – outer layer of cells Inner cell mass – cluster of cells at one end of blastocyst Cleavage and blastocyst formation

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 29.2 Figure 29.2 Cleavage and Blastocyst Formation

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Occurs about 7 days after fertilization Trophoblast enlarges and spreads Maternal blood flows through open lacunae Gastrulation Embryonic disc composed of germ layers Endoderm Mesoderm Ectoderm Implantation

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 29.3 Stages in Implantation Animation: Location of the Endometrium PLAY Figure 29.3

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 29.4 Figure 29.4 The Inner Cell Mass and Gastrulation

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Gastrulation By day 12 surface cells move toward the primitive streak A third germ layer forms The three germ layers are: Ectoderm – superficial cells that did not migrate Endoderm – cells facing the blastocoele Mesoderm – migrating cells between ectoderm and endoderm Germ layers

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Four extraembryonic membranes: Yolk sac Amnion Allantois Chorion Extraembryonic Membranes

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 29.5a, b Figure 29.5 Extraembryonic Membranes and Placenta Formation

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 29.5c, d Figure 29.5 Extraembryonic Membranes and Placenta Formation

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 29.5e Figure 29.5 Extraembryonic Membranes and Placenta Formation

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Yolk sac Important site of blood cell formation Amnion Encloses fluid that surrounds and cushions developing embryo Allantois Eventually becomes bladder Chorion Embryo Anatomy

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 29.6a Figure 29.6 A Three-Dimensional View of Placental Structure

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Chorionic villi extend into maternal tissue Forms intricate branching network for maternal blood Umbilical cord connects fetus to placenta Placentation

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Trophoblast secretes hormones to maintain pregnancy HCG Estrogens Progesterone hPL Placental prolactin relaxin Hormones of the placenta