4 week embryo 5 mesenchymal prominences (facial primordia) appear in relation to the stomodeum (a depression in the surface ectoderm which marks the future mouth…
Explore more Face and Palate Development – Embryology made Easy
Embryology
Heart Development – Embryology Made Easy
Heart Tube At the beginning of 4th week of development, heart is a continuous and valveless linear tube that resembles a chicken hung upside-down. It consists…
Explore more Heart Development – Embryology Made Easy
Embryology Week 3: Trimalinar Germ Disc
In the Week 2, we had a bilaminar germ disc with 2 cavities (amniotic cavity and yolk sac) suspended in the chorionic (extraembryonic cavity) by…
Explore more Embryology Week 3: Trimalinar Germ Disc
Embryology Week 2: Rule of Twos
Starting from Day 8, blastocyst progressively invades into the endometrial stroma and there is formation of: 2 layers in Trophoblast: 1. Inner mononulcear Cytotrophoblast (Cellular)…
Explore more Embryology Week 2: Rule of Twos
Embryology Week 1: Cleavage to Implantation
Following events occur in the zygote formed in the week zero of development: Cleavage Approximately 24 hours after fertilization the zygote begins with the first…
Explore more Embryology Week 1: Cleavage to Implantation
Embryology Week 0: Gametogenesis, Ovulation and Fertilization
Gametogenesis – formation of gametes from primitive germ cells Spermatogenesis, begins at puberty and occurs in seminiferous tubules (spermiogenesis occurs in sertoli cells). One spermatogenesis takes an…
Explore more Embryology Week 0: Gametogenesis, Ovulation and Fertilization
Germ Layer Derivatives – Mnemonics
Principle of Germ Layer Segmentation Ectoderm gives further rise to neuroectoderm and neural crest cells. Endoderm remains intact. Mesoderm gives further rise to paraxial mesoderm…
Explore more Germ Layer Derivatives – Mnemonics
Branchial Apparatus Made Easy
Synonym: Pharyngeal apparatus Branchial (resembling fish gills) apparatus is like a sandwich – mesoderm and neural crest cells (branchial arch) between opposing outer ectoderm (cleft or…
Explore more Branchial Apparatus Made Easy