Principles of Medical Embryology PDF

Principles of Medical Embryology 20/10/23, 11:56 PM Principles of Medical Embryology Key terminology • Gamete: mature haploid male or female germ cell which is able to unite with another of the opposite sex in sexual reproduction to form a zygote • • • Embryonic period: weeks 3 - 8 in humans Ter...

Principles of Medical Embryology 20/10/23, 11:56 PM Principles of Medical Embryology Key terminology • Gamete: mature haploid male or female germ cell which is able to unite with another of the opposite sex in sexual reproduction to form a zygote • • • Embryonic period: weeks 3 - 8 in humans Teratogen: cause irreversible, deleterious structural malformations in fetuses Mutagen: cause changes (mutations) in the genetic material of cells Phases of embryogenesis 1. Gametogenesis • • Formation of gametes Spermatogenesis: formation of male gametes ◦ • Occurs at puberty and continues throughout life Oogenesis: formation of female gametes ◦ Primary oocytes begin meiosis by weeks 28-30 but arrest in prophase until puberty 2. Fertilisation • Union of gametes - fusion of sperm and oocyte to form a zygote 3. Cleavage • • Period of rapid mitotic cell division with no increase in size Formation of morula then blastocyst (days 1-4) 4. Gastrulation • • Formation of the germ layers - ectoderm, mesoderm, endoderm Body axis established 5. Embryonic folding • Formation of the body plan 6. Organogenesis • • Formation of organs and organ systems Basis in place by end of embryonic period, development continues through fetal period 7. Fetal period • • • • • From week 9 until birth Growth, weight gain Tissues mature and become functional Overt sexual differentiation Bone laid down; connections made in CNS Primary processes of embryonic development https://galvanized-borogovia-4fa.notion.site/Principles-of-Medical-Embryology-f92f304e4e2a4f29a66d31ae71a0df44 Page 1 of 2 Principles of Medical Embryology 20/10/23, 11:56 PM • • • Cell division Differentiation Cell attachment • • • Apoptosis Induction Cell migration Secondary processes of embryonic development • Axis formation • Folding/rotation Factors resposible for the regulation of embryonic development • Genetic • Epigenetic • Environmental influences https://galvanized-borogovia-4fa.notion.site/Principles-of-Medical-Embryology-f92f304e4e2a4f29a66d31ae71a0df44 Page 2 of 2