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19 Cards in this Set
- Front
- Back
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After fertilization, the zygote develops by rapid cell divisions, the first divisions are called ____. |
Cleavages.
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Early embryology.
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Page 88.
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What is a morula?
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A thigh bunch of cells.
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What is blastulation?
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A process in which the morula gradually becomes hollow, as if inflated with fluid.
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What is a blastula?
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A hollow sphere of cells.
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What is a blastocoel?
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It is a fluid filled cavity in the blastula.
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What are the two specialized parts that the blastocoel develop into?
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The inner cell mass which will become the embryo and the trophoblast, which will become the placenta.
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What is gastrulation?
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A process in which the cells of the blastula separate into three distinct layers.
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What are the three distinct layers that will be formed by the cells of the blastula.
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The outer most layer, ectoderm, the middle layer, mesoderm, the inner most layer, the endoderm.
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What does the ectoderm consists of?
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The skin and the nervous system.
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What does the mesoderm consist of?
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It develops into the internal organs and the musculoskeletal, circulatory, and excretory systems.
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What does the endoderm consist of?
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It forms the lining of the digestive tract and the organs of the digestive system.
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What is a gastrula?
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It is the assemblage; when the three layers have become apparent.
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What is neurulation?
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It is a process after gastrulation and it is when a hollow cord of cells in the mesoderm develops into the notochord, which is the spinal column.
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Derivatin of major tissue and organs diagram.
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Page 89.
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What is the term called after 8 weeks of grown for the embryo?
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A fetus.
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How does the umbilical cord develop?
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It develops from the two embryonic sacs, the yolk sac (The site of earl blood vessel development) and the allantois (an outpocketing of the gut that contains many blood vessels).
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When is the placenta formed?
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It is formed when part of the chorion (a membrane that surrounds the amnion, which is the strong sac that houses the fetus and contains amniotic fluid) fuses to the uterine walls.
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What are some processes that the placenta do?
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It supplys nutrients, removes wates, prvents toxins and drugs from entering the fetus, fuctions as an endocrine gland, producing essential hormones such as progesterone, estrogen, etc.
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