Embryology Flashcards
What are the stages with at would be involved in forming the trilaminar disc
Gastrulation
There would be the primitive streak, node and pit
The cells would move down the streak and would form the endoderm
The cells from the hypoblast would be displaced and would form the middle mesoderm
The epiblast would not move and would form the ectoderm
What would happen if there is the irregular movement of the cells through the primitive streak
The bilateral movement would form the INTRAEMBRYONIC MESODERM
The cells could migrate bilaterally and cranially to from the CARDIOGENIC MESODERM
Cells migrate back through the hypoblast and would from the DEFINITIVE ENDODERM
what are the functions of the primitive streak
Formation of the trilaminar disc
Formation of the body axis
Cranial-caudal end (head and tail)! Dorsal-ventral (back and body), right-left and medial-lateral
What is the step that follows gastrulation and what is its purpose
Neuralation forming the brain and the spinal cord
This would then from the neural plate, the neural tube and the neural fold
The notochord would then from under
What are some of the neural tube defects.
Anacephaly this is when the neural tube does fully fold in the brain
Spina bifia is when the neural tube does properly form in the cervical region of the body
What is the notochord and what does it form
The notochord forms under the neural tube
This would then form the nucleus purpulsus (the central, soft area of the vertebrae)
What do the somites form
The somites would have the scleratome (spinal chord), myatome (muscles) and the dermatome (the skin)
How does the trophoblast form the synthiotrophoblast
The trophoblasts would from the placenta
This trophoblastic placenta would then allow the formation of the sythiotropoblast
Which would adhere and invade the wall of the endometrium
Which layer forms the primitive yolk sac
The hypoblast
What is the amniotic cavity
A gap (normally containing the amniotic fluid) that would from within the bilaminar disc (made is the epiblast and the hypoblast)
What is the amniotic cavity surrounded by
This would be surrounded by the amnion
This would be a thin membrane that would be one of the four extra embryonic membranes
What is the inner trophoblast lined with in the second week
The amnion and the yolk sac would be surrounded by the extra embryonic mesoderm
What happens when the extraembryonic cavity splits into two layers
The chorionic cavity would form
What is the difference between the choroin and the chorionic cavity
The chorionic cavity would form when the extra embryonic mesoderm would divide into two. This would then allow a layer to form
The chorion would be a layer, like the amnion and the yolk sac
