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pregnancy & developm
pregnancy and development
Question | Answer |
---|---|
what is the structure surrounding an egg | corona radiata |
how sperm fertilize an egg | 1 |
what much the sperm breakthrough to get to the egg | corona radiata layer |
when a sperm reach an egg, enzymes are released from ..... at the sperm head | acrosome |
where does fertilization actually take place | fallopian tubes |
how often does a fertilized egg divide | once a day for the first 5 days |
what is the ball of cells called after the first 5 days | morula |
what happens to the morula after 5 days | cells become hollow with stem cells inside that develop into a fetus |
when the ball of stem cells deposit in the uterine wall it is now called a | blastocyst |
name the outer cells of the blastocysts | trophoblast |
what does trophoblast do | invade the endometrium wall |
why doe the trophoblast invade the endometrium wall | to start forming the placenta and umbilical cord for baby to recieve nutrients from the mother |
what prevents the egg shell within the ovary from degenerating | hCH Human Chorionic Gnadotropin |
the site of gas exchange within a fetus | chorionic villi |
how is oxygen provided and waste removed from a fetus | through the chorionic villi and unbilical cord |
at 2 weeks the trophoblast had developed into | yolk sac and amnion |
the yolk sac structure will become the... of the baby | digestive tract |
the amnion will become the... during the pregnancy | amniotic sac |
between the yolk sac and the amnion are 3 layers called | germ layers |
what are the 3 germ layers | endoderm (yolk side) mesoderm (middle side) ectoderm (amnion side) |
the ectoderm will develop into | nervous system, skin, nails, eyes |
the mesoderm will develop into | muscular system, skeletal system, reproductive system, urinary system and cardiovascular system |
the ectoderm will develop into | lungs, digestive system and liver |
the nervous system starts as a sheet of cells and folds over to form | neural tube |
if the neural tube doesn't fully complete and close off what happens | baby born with spina bifida |