PSY 220 Lecture Notes - Lecture 18: Antidepressant, Influenza, Eclampsia
1 Nov 2016
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Document Summary
Fertilization usually occurs within 24 hours of ovulation. The single-celled zygote begins to divide 24-36 hours after fertilization. The mass has 16 cells and is called a morula; it is traveling down the fallopian tube to the uterus. An inner cell mass forms; the entire mass is called a blastocyst and is the size of a pinhead. The blastocyst attached to the wall of the uterus. The blastocyst becomes fully embedded in the wall of the uterus; it now has about. Now an embryo, the person to be is just 1/10 of an inch (2 mm) long. It has become elongated, and three layers emerge the ectoderm, mesoderm, and endoderm. The embryo is so curved that the two ends almost touch. The outer layer (ectoderm) folds into the neural tube. From the mesoderm, a tiny heart forms and. The endoderm differentiates into a gastrointestinal tract and lungs/ between days 21 and 28, eyes develop.
