What are the derivatives of somites?
The somites eventually diverge into sclerotome (cartilage), syndotome (tendons), myotome (skeletal muscle), dermatome (dermis), and endothelial cells, each corresponding to different regions within the somite itself.
What does paraxial mesoderm differentiate into?
The paraxial mesoderm gives rise to the axial skeleton. The lateral plate mesoderm gives rise to the appendicular skeleton.
Which structure is derived from paraxial mesoderm?
A particular kind of tissue deriving from the paraxial mesoderm is the head mesoderm. This tissue derives from the unsegmented paraxial mesoderm and prechordal mesoderm. Tissues derived from the head mesoderm include connective tissue and the muscles of the face.
How paraxial mesoderm is formed?
Paraxial mesoderm is formed bilaterally adjacent to the neural tube in the mouse embryo and becomes progressively segmented along the rostral-to-caudal axis to generate the somites.
What are somites quizlet?
Somites are transient structures that do not exist in the adult. They disappear as organogenesis proceeds. – Somites direct the migration paths of several structures (e.g., neural crest, spinal nerves). – Somites give rise to cells that form vertebrae, ribs, most skeletal muscle and dermis of dorsal skin.
What is the function of ectoderm?
Ectoderm Function The main function of the ectoderm is to form the central nervous system (brain and spinal cord). Following gastrulation, the mesoderm forms the rod-like notochord which signals the adjacent dorsal ectoderm to thicken and form the neural plate.
What is Somitomere and somite?
Somitomeres are segmented mesenchymal units that appear in anterior to posterior order, and except in cranial regions, later form into somites. Most of the study focused on the formation of the first six somites. These early somites are formed somewhat differently from later ones.
What do you mean by paraxial rays?
A paraxial ray is a ray which makes a small angle (θ) to the optical axis of the system, and lies close to the axis throughout the system.
Where is the paraxial mesoderm?
The presomitic paraxial mesoderm is located adjacent to the notochord and neural tube and constitutes a longitudinal column of cells on either side of the notochord.
What are somites simple definition?
: one of the longitudinal series of segments into which the body of many animals is divided : metamere.
What structure does embryo develop?
Development of the Embryo. The next stage in development is the embryo, which develops within the amniotic sac, under the lining of the uterus on one side. This stage is characterized by the formation of most internal organs and external body structures.
Where does the Hox gene specify the position of the somite?
The Hox genes specify somites as a whole based on their position along the anterior-posterior axis through specifying the pre-somitic mesoderm before somitogenesis occurs.
Where do the primitive segments of somitogenesis form?
The somites (outdated term: primitive segments) are a set of bilaterally paired blocks of paraxial mesoderm that form in the embryonic stage of somitogenesis, along the head-to-tail axis in segmented animals.
How does the development of somites depend on the clock?
The development of the somites depends on a clock mechanism as described by the clock and wavefront model. In one description of the model, oscillating Notch and Wnt signals provide the clock. The wave is a gradient of the FGF protein that is rostral to caudal (nose to tail gradient).
Where are the somites located in the zebrafish?
In the zebrafish, the boundary between the most recently separated somite and the presomitic mesoderm forms between ephrinB2 in the posterior of the somite and EphA4 in the most anterior portion of the presomitic mesoderm (Figure 14.5A; Durbin et al. 1998). As somites form, this pattern of gene expression is reiterated caudally.
