Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Development of Limbs (4th to 8th Week) Chronology of Limb Development 4 stages of Limb Development 1.) Initiation limb bud formation 2.) Specification of limb pattern growth of the 3 axis occurs 3.) Tissue formation and limb morphogenesis limb elements form 4.) Growth occurs into early adulthood Migration of Lateral Plate Mesoderm SEM of Limb Bud from a Day 29 Embryo Normal Chick Limb Anatomy Role of Apical Ectodermal Ridge and Mesodermal Core in Limb Bud Development Formation of Supernumerary Limbs Meromelia The Generation of Limbless Vertebrates Snake Axial Skeleton Formation of Snake Hindlimb Is regeneration of limbs possible? Newt Limb Regeneration This is a time-lapse sequence showing the stages of newt limb regeneration. The surgical amputation was at the level of the humerus. The pictures show the wound-healing, de-differentiation, blastema and re-differentiation stages of regeneration. Total time shown is approximately 20-25 days. Patterning of the Antero-Posterior Axis: Transplantiaton of ZPA Evidence for a Morphological Gradient Established by the ZPA Retinoic Acid Transplantation Experiment Retinoic acid induces mirror polydactyly Whole mount of chick embryo showing expression of Sonic Hedgehog Polydactyly showing partial duplication of the right foot and toes Establishment of the Dorso-Ventral Axis Forelimb versus Hindlimb Signals Time Course of Upper and Lower Limb Development Formation of the Hand Webbed Hand (Syndactyly) Nucleoli Differences in Chick and Quail Chick Quail Quail-chick Cell Tracing Experiment Limb Musculature Develops from Ventral and Dorsal Condensations of Somitic Mesoderm Dorsal Muscle Mass extensors and supinators upper limb extensors and abductors lower limb Ventral Muscle Mass flexors and pronators upper limb flexors and adductors lower limb Bone Development X-rays of Bone Growth Cogenital Anomalies of Limb 1.) Reduction defects Meromelia Amelia 2.) Duplication defects Polydactyly 3.) Dysplasia Syndactyly Gigantism Critical Periods in Human Prenatal Development