Embryonic Development Minimal Requirements for Lab
Identify Structure and Name Function
I. Models
A. Know the stages of embryonic development and their internal structures:
1. Study development from a zygote to a gastrula, identify the stages in
anatomical models and in microscope slides, and identify the structures/name
function of the stages shown below:
i. Fertilization – fusion of pronuclei to form a zygote
ii. Cleavage – formation of blastomeres (2-, 4-, 8- and 16-cell stages)
iii. Morula
iv. Blastula
1) Inner cell mass (ICM)
2) Blastocoele (blastocyst cavity)
3) Trophoblast
v. Gastrulation – formation of the trilaminar disk (3 primary germ layers)
from the bilaminar disk (hypoblast and epiblast)
1) Endoderm
2) Mesoderm
3) Ectoderm
B. Distinguish between embryo and fetus
1. Embryo – 0 to 8 weeks
2. Fetus – 9 weeks to birth
C. Know the events and timing of implantation
1. Implantation
i. Fetal portion – chorion that develops from the trophoblast
1) Cellular trophoblast (cytotrophoblast)
2) Synctial trophoblast (syncytiotrophoblast)
i. Chorionic villi – containing embryonic blood
vessels
D. Study the events of extraembryonic membrane formation and identify/name
function the membranes and structures forming the umbilical cord
1. Extraembryonic membranes
i. Yolk sac
ii. Amniotic sac
iii. Allantois – within the body stalk
iv. Chorion
2. Umbilical cord – containing 2 umbilical arteries and 1 umbilical vein
Identify Structure and Name Function
I. Models
A. Know the stages of embryonic development and their internal structures:
1. Study development from a zygote to a gastrula, identify the stages in
anatomical models and in microscope slides, and identify the structures/name
function of the stages shown below:
i. Fertilization – fusion of pronuclei to form a zygote
ii. Cleavage – formation of blastomeres (2-, 4-, 8- and 16-cell stages)
iii. Morula
iv. Blastula
1) Inner cell mass (ICM)
2) Blastocoele (blastocyst cavity)
3) Trophoblast
v. Gastrulation – formation of the trilaminar disk (3 primary germ layers)
from the bilaminar disk (hypoblast and epiblast)
1) Endoderm
2) Mesoderm
3) Ectoderm
B. Distinguish between embryo and fetus
1. Embryo – 0 to 8 weeks
2. Fetus – 9 weeks to birth
C. Know the events and timing of implantation
1. Implantation
i. Fetal portion – chorion that develops from the trophoblast
1) Cellular trophoblast (cytotrophoblast)
2) Synctial trophoblast (syncytiotrophoblast)
i. Chorionic villi – containing embryonic blood
vessels
D. Study the events of extraembryonic membrane formation and identify/name
function the membranes and structures forming the umbilical cord
1. Extraembryonic membranes
i. Yolk sac
ii. Amniotic sac
iii. Allantois – within the body stalk
iv. Chorion
2. Umbilical cord – containing 2 umbilical arteries and 1 umbilical vein
