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Jan 1, 1000
Week 1 - The Preimplantation Period
-An ovum, an unfertilized female gamete, is released from the ovary and begins to travel down the fallopian tube.
-A sperm cell meets the ovum and penetrates it, which fertilizes the cell and makes it an egg.
-The nucleus of the sperm cell combines with the egg becoming a single cell or a zygote.
-The zygote begins to divide into many cells while traveling down the fallopian tube, also known as mitosis. Once the division is complete the zygote is now known as a blastocyst. -
Feb 2, 1000
Week 3-8 Embryonic Stage
-Begins when blastocyst implants itself into uterine wall.
-Formation of 3 cell layer*
-Nervous system develops
-Most organs begin to develop -
Feb 3, 1000
Week 2 (Day 8-9) - Implantation
-Blastocyst makes it to the uterus and out of the fallopian tube.
-Implants itself into the uterine wall lining
-Implanted blastocyst grows by increased proliferation
-Increased number of embryonic cells = emryonic cell layers
-Bilaminar ebryonic disc has superior (epiblast) and inferior (hypoblast) layers -
Feb 4, 1000
Week 3 - Development of Embryonic Cell Layers
-Primitive streak forms
-Embryonic cell forms into three layers
-Endoderm (inner layer)
-develops into cells of most internal glands and organs
- Mesoderm (middle layer)
-develops into bones and muscle cells
-Ectoderm (outer layer)
-develops into skin and nerve cells
-Neural tube formation and development of blood circulation begin
-Cell now has cephalic (head) and caudal (tail) end
-CNS begins to form
-Neural groove begins to form and is protected by neural folds -
Feb 5, 1000
Week 4
-Embryo undergoes emryonic folding
-Face and neck begins to form
-Eyes, nose, oral cavity (stodum), and jaw area is visible
-two mandibular processes are forming
-forms the mandibular arch -
Week 5
-Intermaxillary Segment forms
-Gives rise to the primary palate -
Week 8
-Formation of tongue is complete
-Extimesenchyme -
Week 6-7
-Bilateral maxillary gives rise to two palatal shelves forming the
-Tongue begins to form on the floor of the primitive pharynx
-Maxillary process fuses with medial nasal process
-Dental Lamina (week 7) -
Week 10 "Cap Stage"
-Tooth germ
-Dental sac
-morphogenesis -
Week 11 "Bell Stage"
-Outer and inner enamk epithelium forms
-Stellate reticulum forms
-Stratum untermedium forms -
Week 12 "Bud stage"
- All three processes fuse to form the final palate -odontoblast and dentin matrix
