KIVO Med
The fourth week of embryonic development
Follow embryonic folding, neurulation and the first organ primordia from the third to the fourth week.
- 106 explained questions
- 39 flashcards
- 112 estimated course minutes
Updated
What you will learn
- Explain the longitudinal and transverse folds that isolate the embryo from its extra-embryonic annexes.
- Describe the three stages of neurulation and closure of the neuropores.
- Relate the three germ layers to their first derivatives and to segmentation into somites.
- Describe fetoplacental circulation and the appearance of the limb buds.
Course outline
Entering the fourth week
Place the fourth week in time and see its major events before studying each mechanism.
6 min
Delimitation: closing the embryo
Understand the overall purpose of the longitudinal and transverse folds.
8 min
Longitudinal delimitation
Describe the craniocaudal fold and incorporation of the primitive gut.
10 min
Transverse delimitation and the coelom
Follow the meeting of the lateral edges and formation of the future peritoneal cavity.
8 min
Neurulation: from neural plate to neural tube
Describe the three stages of neuroectoblast formation and neuropore closure.
12 min
Early ectodermal derivatives
Identify neuroectoblast, epiblast and the sensory placodes.
8 min
Primitive gut and endodermal derivatives
Distinguish the foregut, midgut and hindgut and their early derivatives.
10 min
Axial and paraxial mesoderm: notochord and somites
Relate the notochord and somites to their derivatives and segmentation.
12 min
Intermediate mesoderm and lateral plate
Describe the renal derivatives and internal cavities formed by mesoderm.
10 min
Establishment of fetoplacental circulation
Follow fetal blood and oxygenated blood through the umbilical cord.
7 min
Appearance of the limb buds
Locate the upper and then lower limb buds by their somitic levels.
6 min
Reading a lesion through the metameres
Relate segmentation to symptoms that may follow a vertebral lesion.
7 min
End of embryogenesis and vulnerability
Review the fourth-week shape and its high teratological sensitivity.
8 min
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Educational resources for medical studies; they do not replace your faculty’s teaching or medical advice.
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