Developmental Stages Overview
Directions:
a. Click the “Contents” button.
b. Open the Reproductive System File.
c. Click Anatomy Overviews.
d. Click Developmental Stages Overview.
Work through each of the following stages showing 9-month development from a single celled zygote to 6-7 pound newborn.
1. In the diagram below, identify cleavage, morula, blastocyst, and implantation, all of which are events or structures developed in the first week following fertilization.
2. Return to the Developmental Stages homepage and click the Week two blastocyst. Identify each of the following:
b. Describe primary epiderm (epiblast) and primary endoderm (hypoblast) development.
c. Describe the bilaminar embryo location within the blastocyst.
d. Describe chorion development and function.
3. a. Return to the Developmental Stages homepage and click on the third week embryo. Describe the following Week 3 developments:
gastrulation -
hollow nerve tube -
somites -
placenta -
b. Identify each of the following structures from this transverse view of a week three embryo.
c. Return to the main Week 3 page and click on the posterior view. Identify each of the following:
d. Return to the main Week 3 page and click on the lateral view / sagittal section. Identify each of the following:
4. a. Return to the Developmental Stages main homepage and click on the fourth week embryo. Describe the following Week 4 developments:
heart tube -
digestive system -
eyes & ears -
limb buds -
b. Click on the Heart to examine a ventral view. Identify each of the following:
c. Return to the main Week 4 page and click on the transverse section. Identify each of the following:
d. Return to the main Week 4 page and click on the lateral view / sagittal section. Identify each of the following:
5. a. Return back to the main Developmental Stages page and click on the 5-8 week embryo. Describe development of the following during this period:
head -
limbs -
reproductive structures -
lungs & heart -
b. Click the reproductive organs and identify the following:
c. Return to the Weeks 5-8 page and click on the lungs and heart. Identify each of the following:
d. Return again to the main Weeks 5-8 page and click on the lateral view. Identify each of the following:
6. Return all the way back to the Developmental Stages homepage and click on the Weeks 9-12 fetus. Describe each of the following during this period:
a. When does “fetal development” begin?
b. head development -
c. gender determination -
d. movement & heartbeat -
e. ossification & system development -
f. Identify each of the following:
7. a. Back again to the Developmental Stages homepage. This time, investigate Weeks 13-16 by identifying each of the following:
b. Describe head and body proportionality at this stage.
c. Describe eye and ear positioning.
d. Describe movement.
8. Go back to the Developmental Stages page and investigate Weeks 17-20.
a. Describe growth during this stage.
b. Describe movement during this stage.
c. Identify each of the following:
9. Back, again, to the Developmental Stages page and investigate Weeks 21-25.
a. Describe head and body proportionality.
b. Describe premature birth concerns at this stage.
c. Identify each of the following:
10. Return to the Developmental Stages page and move next to Weeks 26-29.
a. Describe developmental events during this period.
b. Identify each of the following:
11. Back to the Developmental Stages page and move next to Weeks 30-34.
a. Describe developmental events during this period.
b. Identify each of the following:
12. One last time, back to the Developmental Stages page to examine Weeks 35-38.
a. Describe nervous system development following birth.
b. Identify each of the following: