What is unsegmented paraxial mesoderm?
These bands of paraxial mesoderm are referred to as the segmental plate (in birds) and the unsegmented mesoderm (in mammals). As the primitive streak regresses and the neural folds begin to gather at the center of the embryo, the paraxial mesoderm separates into blocks of cells called somites.
What is Epimere and Hypomere?
Epimere – Segment of myotome that is dorsal to the body axis. Hypomere – Segment of myotome that is ventral to the body axis. Mesenchyme – A primordial embryonic connective tissue, consisting of stellate cells and a loose, fluid extracellular matrix.
What is Primaxial and Abaxial?
The primaxial domain comprises somitic cells that develop within somite-derived connective tissue, and the abaxial domain includes muscle and bone that develop within lateral plate-derived connective tissue. The boundary between the two domains is the lateral somitic frontier (Fig. 2).
What is a Hypomere?
[ hī′pə-mîr′ ] n. The portion of the myotome that forms muscle of the body wall and that is innervated by a branch of a spinal nerve. The somatic and splanchnic layers of the lateral mesoderm that give rise to the lining of the celom.
What is nieuwkoop Center?
Nieuwkoop center refers to a conceptual domain that generates intercellular signaling molecules to induce the dorsal organizer in early embryonic development. Axis Formation – Formation and Function of the Dorsal Organizer.
What is the meaning of abaxial surface?
: situated out of or directed away from the axis the abaxial or lower surface of a leaf.
What is the lateral Somitic frontier?
The lateral somitic frontier is a cryptic developmental boundary that marks the border between two distinct lineage domains initially determined by gastrulation movements, and later by the lineage of the mesenchyme that generates the connective tissue.
How Prechordal is formed?
The prechordal plate is a thickening in the endodermal layer which is formed by mesendodermal cells from the primitive node that migrate rostrally along the midline between the ectoderm and endoderm layers. These same cells also form the notochord.