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VERTEBRATE DEVELOPMENT BIOL 4410 DEVELOPMENTAL BIOLOGY AS A SCIENCE

VERTEBRATE DEVELOPMENT BIOL 4410 DEVELOPMENTAL BIOLOGY AS A SCIENCE. http://embryo.soad.umich.edu/carnStages/carnStages.html. WHY BOTHER WITH EMBRYOLOGY?. 1. BECAUSE IT TEACHES US ABOUT OURSELVES 2. BECAUSE IT ALLOWS US TO ASSESS AND PERHAPS TREAT PROBLEMS THAT ARISE DURING PREGNANCY.

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VERTEBRATE DEVELOPMENT BIOL 4410 DEVELOPMENTAL BIOLOGY AS A SCIENCE

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  1. VERTEBRATE DEVELOPMENT BIOL 4410 DEVELOPMENTAL BIOLOGY AS A SCIENCE http://embryo.soad.umich.edu/carnStages/carnStages.html

  2. WHY BOTHER WITH EMBRYOLOGY? 1. BECAUSE IT TEACHES US ABOUT OURSELVES 2. BECAUSE IT ALLOWS US TO ASSESS AND PERHAPS TREAT PROBLEMS THAT ARISE DURING PREGNANCY. 3. BECAUSE IT GIVES US INSIGHT INTO THE CAUSES OF AND POSSIBLY TREATMENT FOR A VERY LARGE NUMBER OF “DISEASE” CONDITIONS SEEN IN BOTH CHILDREN AND ADULTS. BIRTH DEFECTS - TERATOLOGY

  3. Teratology - comes from the Greek work meaning “monster” or “marval”. - study of disfiguring birth defects or malformations. These may be due to environmental effects, gene mutations, or both. Thomas Quasthoff - famous baritone singer who has thalidomide induced birth defects. Hydrocephalus Spina bifida Tethered cord syndrome - tissue attachments that form during development of the fetus within the womb and that limit the movement of the spinal cord within the spinal column. Can result in progressive sensory and motor problems as person ages (e.g., bowl and/or bladder incontinence, weakness in legs). Surgical intervention during childhood may prevent further problems. Fetal repair, 1999 The fetus’ arm flopped out of the womb as the surgeon prepared to close the incision. The surgeon is lifting it to put it back in. Both mother and fetus were anesthetized. Partial list of genetic developmental defects http://www.gfmer.ch/genetic_diseases_v2/index.php

  4. THE LOGIC OF DEVELOPMENT Zygote Ejaculation Organogenesis Ovulation Histogenesis Gastrulation Fertilization Cleavage 1. Ovulation 2. Ejaculation 3. Fertilization 4. Zygote 5. Cleavage 6. Gastrulation 7. Organogenesis 8. Histogenesis

  5. THE FACTS OF LIFE Fundamental questions: Where did I come from????? How was I formed?????

  6. THE FACTS OF LIFE What’s the very first thing you must have in order for sexual reproduction to occur?

  7. THE FACTS OF LIFE What were you 30 years ago???? A potential What tangible part of your mother and father represented that potential you????

  8. THE FACTS OF LIFE Where in your father were these genes located? In a stem cell called a SPERMATOGONIUM. Located in a seminiferous tubule in one of your father’s testicles. Where in your mother were these genes located? In an immature egg called an OOCYTE. Located in a primordial follicle in one of your mother’s ovaries.

  9. THE FACTS OF LIFE Points out a fundamental difference between males and females. In males, reproductive stem cells (spermatogonia) function to produce gametes (sperm) from puberty until death. In females, reproductive stem cells are only functional while a given female is an embryo in her mother’s womb (i.e. Once born, a female has all the eggs she will ever have).

  10. THE FACTS OF LIFE Formation of the gametes that would contribute to your existence. Spermatozoon - spermatogenic cycle that would produce that very special spermatozoon (1/2 of you) began about 11 months before you were born (i.e. about 2 months before your conception).->spermatogenesis Would reach maturity a few days before your conception. Ovum/oocyte- oogenic cycle that would produce that very special egg (1/2 of you) began during the second month of your mother’s development in her mother’s womb.->oogenesis Would reach maturity about 24 hrs before your conception.

  11. THE FACTS OF LIFE So, what happened next that resulted in you? About 9 months before you were born your parents had intercourse (copulation, coitus). And, what about the gametes that would create you? Egg ovulated sometime during the preceding 24 hr. Was one of millions formed during your mother’s embryogenesis. (or if you’re a fraternal twin, triplet, etc., then 2, 3, etc. eggs were ovulated) Ejaculation - 100s of millions of spermatozoa. Only one of these had a future (or if you’re a fraternal twin, triplet, etc. then 2, 3 etc. had a future).

  12. THE FACTS OF LIFE Sperm must get to the egg -> how is this accomplished? Mainly by 1. Muscular contractions of the wall of the uterus and oviducts 2. Ciliary currents in the oviducts Sperm meets egg in upper oviduct where FERTILIZATION occurs. Suddenly you are more than a potential!

  13. Birth THE FACTS OF LIFE Fertilization creates a diploid cell - the ZYGOTE The zygote undergoes CLEAVAGE -> multicellular embryo The embryo implants in the uterine wall - IMPLANTATION Further development occurs -> e.g. PLACENTATION GASTRULATION ORGANOGENESIS HISTOGENESIS GROWTH And 9 months later, there you are

  14. THE FACTS OF LIFE SUMMARY: Formation and maturation of male and female gametes Fertilization Placentation and Embryogenesis -> cleavage, gastrulation, organogenesis, etc. Birth Further development What does all this mean? How is all this accomplished? That’s what this course is about!

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