EMBRYONIC DEVELOPMENT. OVERALL IDEAS DEVELOPMENT BEGINS AFTER FERTILIZATION OF THE EGG BY THE SPERM...
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Transcript of EMBRYONIC DEVELOPMENT. OVERALL IDEAS DEVELOPMENT BEGINS AFTER FERTILIZATION OF THE EGG BY THE SPERM...
EMBRYONIC DEVELOPMENT
OVERALL IDEAS
DEVELOPMENT BEGINS AFTER FERTILIZATION OF THE EGG BY THE SPERM
ZYGOTE IS DEFINED AS A FERTILIZED EGG CELLS BECOME MORE DIFFERENTIATED AS
THE STAGES OF DEVELOPMENT CONTINUE THE ZYGOTE WILL NOW GO ON TO DEVELOP
INTO AN EMBRYO AND EVENTUALLY A FETUS
STAGES OF EMBRYONIC DEVELOPMENT CLEAVAGE BLASTULA FORMATION GASTRULA ORGANOGENESIS EVENTUALLY BIRTH
Our Journey begins at FERTILIZATION-DESCRIBE WHAT HAPPENS HERE?
FERTILIZATION
FUSION OF SPERM AND THE EGG A ZYGOTE IS FORMED HAPLOID IS NOW DIPLOID (46
CHROMOSOMES) NOW WE CAN DEVELOP
STAGE 1-CLEAVAGE: DESCRIBE WHAT HAPPENS HERE?
STAGE 1-CLEAVAGE
RAPID MITOTIC CELL DIVISION MAKING MORE CELLS FOR THE INDIVIDUAL
NO CELL GROWTH ALL CELLS ARE EMBRYONIC NOT DIFFERENTIATED NO FATE YET.
CAN FORM INTO ANY CELL TYPE THIS STAGE IS WHERE THE ORGANISM
IS CONSIDERED AN EMBRYO
STAGE 2-BLASTULA FORMATION- WHAT HAPPENS HERE?
STAGE 2- BLASTULA STAGE
ROUND HOLLOW BALL OF WITH A SINGLE LAYER OF CELLS. FLUID FILLED WITH CYTOPLASM
CELLS CONTINUE TO DIVIDE
STAGE 3-GASTRULATION
STAGE 3 GASTRULATION
INDENTATION OF BLASTULA FORMS 3 DISTINCT LAYERS
ECTODERM: DEVELOPS SKIN,LINING OF ORGANS OUTER
MESODERM: DEVELOPS MUSCLES,NERVOUS SYSTEM,BLOOD,BONEMIDDLE
ENDODERM: DEVELOPS INNER SYSTEMS (DIGESTIVE,RESPIRATORY)INNER
ORGANOGENESIS
STAGE 4 ORGANOGENESIS
CELLS OF THE LAYERS NOW HAVE A FATE DIFFERENTIATED. CAN NOT FORM ANY CELL TYPE THEY WANT.THEY NOW HAVE A JOB
LAYERS DEVELOP INTO TISSUES AND ORGANS
FULL GASTRULATION OF EMBRYO MOVING INTO A FETUS
HOW DOES THIS IMPACT PREGNANCY? 0-3 MONTHS ZYGOTIC/EMBRYONIC
STAGE CLEAVAGE/BLASTULA 3-6 MONTHS GASTRULA AND SOME
ORGAN DEVELOPMENT 6-9 MONTHS FURTHER ORGAN
DEVELOPMENT, MATURITY,AND FUNCTION
~9 MONTHS FETUS IS BORN
FETUS IN UTERO(IN UTERUS)
CERVIX
UMBILICAL
CORD
PLACENTA AMNIONIC SAC
OVIDUCT
UTERUS
IMPORTANCE OF PLACENTA CONTAINS A
NETWORK OF BLOOD VESSELS WHICH SUPPLY THE FETUS WITH OXYGEN AND NUTRIENTS
JOINS WITH THE UMBILICAL CORD TO SUPPLY THE FETUS WITH NEEDED NUTRIENTS
THOUGHT QUESTION
WHY ARE EMBRYONIC STEM CELLS SUCH A HOT TOPIC IN SCIENCE?
IDEAS
TAKING EMBRONIC STEM CELLS CAN HELP MAKE ANY TYPE OF CELL NOT FATED
RESULTS IN GROWING OF NEW TISSUES OR PERHAPS ORGANS
PROBLEM IS TAKING IT FROM AN UNBORN CHILD