Chapter 29: Human Development Flashcards
Oxygen, Carbon dioxide, nutrients, and wastes cross the placenta by the process of ________.
diffusion
What structures arise from the mesoderm?
- dermis
- gonads
- skeletal muscles
Bone loss that is severe enough to compromise physical health and activity is known as?
osteoporosis
The period from fertilization through the 12th wk is known as the __________.
first trimester
List the correct order of gestational stages.
- preembryonic stage
- embryonic stage
- fetal stage
What are the functions of the amniotic fluid?
- protect fetus from trauma
- allow development of the lungs
- protect fetus from temp fluctuations
What are the 3 features of a blastocyst?
blastocoel, trophoblast, and embryoblast.
What is the w blastocoel?
the outer layer of cells?
What is the trophoblast?
hollow internal cavity of cells
What is the embryoblast?
the cell mass within blastocyst.
What is a zygote?
a single-celled fertilized egg
The process by which a blastocyst attaches to the lining of the uterus is called?
implantation
What structures arise from the endoderm?
- Digestive glands
- epithelium of the digestive tract
- parathyroid gland
Name the stages of developing organism that occur during the preembryonic stage.
- zygote
- cleavage
- morula
- blastocyst
What structures arise from the ectoderm?
- central nervous system
- salivary glands
- epidermis
- portions of the reproductive tract
The function of the____________ is to protect the embryo from trauma, infection, and temp fluctuations, allow freedom of movement, and allow development of the lungs.
Amniotic Fluid
What stage begins 16 days post-conception, after the three germ layers have developed?
embryonic
The stage of ________ is complete when the blastomeres form 3 primary germ layers.
Embryogenesis
Some structures that arise from the mesoderm include:
- dermis
- skeletal muscle
- gonads
What primary germ layer gives rise to most of the epithelium of the digestive and respiratory tracts adn the mucosal epithelium of urinary bladder and urinary tract?
endoderm
When does the embryonic stage begin?
When the 3 germ layers are first present, at about 16 days
Sperm remain viable for ___ days after ejaculation.
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