When is the pre-embryonic period?
The first two weeks of pregnancy
Where does the zygote form?
In the uterine tube
How many mitotic divisions (cleavage divisions) will the zygote undergo to form the morula?
4-5
How long is the Morula stage?
72 hours
How many cells is the morula? Is it bigger or smaller than a zygote?
16-32 cells
The same size as the zygote! (the cells get squished together)
During what stage of early development do cells begin to differentiate into different cell types with specific forms and functions?
The morula stage
What does the morula turn into?
The blastocyst
How long is the blastocyst phase?
5 days
What is the inner cell mass of the blastocyst called?
The embryoblast
What does the embryocyst turn into?
The embryo!
What is the role of the trophoblast? (The outer layer of the blastocyst)
Cells divide to form the chorion
What does the chorion do?
Provides nutrients to the developing embryo
Where does implantation occur? What is being implanted?
The endometrium of the uterine wall
-The blastocyst
Which step of early human development is where most zygotes don’t make it to? (2/3 of all zygotes don’t make it to this step)
Implantation
What does the embryoblast differentiate into? (2 cell layers)
The Bilayered Embryonic Disc
- Epiblast
- Hypoblast
The epiblast will undergo ____ to form _____ and _____.
Mitosis
Amnion
3 germ layers
The hypoblast will undergo _____ to form ________.
Mitosis
The yolk sac
What membranes start to form after implantation?
Extraembryonic membranes
What weeks are the embryonic period?
3rd week to end of 8th week
What are the 3 germ layers?
- Ectoderm
- Mesoderm
- Endoderm
_____ will form the nervous system and epidermis of the skin
Ectoderm
______ will form muscles, cardiovascular system, dermis, and bones
Mesoderm
______ will form epithelial linings of digestive, respiratory, urinary, and reproductive systems along with their associated glands
Endoderm
What period does the heart begin to beat?
The embryonic period
-
Unit 1-Introduction to anatomy9
-
Unit 2-Chemical level of organization53
-
Unit 3: Cellular level of organization56
-
Unit 4: The Cell Cycle, Mitosis, Meiosis52
-
Unit 5: Early Human Development40
-
Unit 6: Heredity (Inheritance)15
-
Unit 7: Histology79
-
Unit 8: Body Cavities, Organs, and Membranes16
-
Unit 9: Integumentary System (aka skin)55
-
Unit 10: The Skeletal System73
-
Unit 11: Muscular System36
-
Unit 12: The cardiovascular system106
-
Unit 13: Lymphatic System19
-
Unit 14: Respiratory System50
-
Unit 15: Digestive System86
-
Unit 16: Urinary System44
-
Unit 17: Reproductive systems99
-
Unit 18: The Endocrine System56
-
Unit 19: Nervous System140
-
Unit 20: Special senses31
