Search results
Results from the WOW.Com Content Network
The dermatome is the dorsal portion of the paraxial mesoderm somite which gives rise to the skin . In the human embryo, it arises in the third week of embryogenesis . [ 2 ] It is formed when a dermomyotome (the remaining part of the somite left when the sclerotome migrates), splits to form the dermatome and the myotome. [ 2 ]
A dermatome is an area of skin that is mainly supplied by afferent nerve fibres from the dorsal root of any given spinal nerve. [ 1 ] [ 2 ] There are 8 cervical nerves (C1 being an exception with no dermatome), 12 thoracic nerves , 5 lumbar nerves and 5 sacral nerves .
[4] [5] However, the segmentation clock model is highly evolutionarily conserved. [6] Intrinsic expression of "clock genes" must oscillate with a periodicity equal to the time necessary for one somite to form, for example 30 minutes in zebrafish, 90 minutes in chicks, and 100 minutes in snakes. [7]
The peripheral nervous system (PNS) is divided into the somatic nervous system, the autonomic nervous system, and the enteric nervous system.However, it is the somatic nervous system, responsible for body movement and the reception of external stimuli, which allows one to understand how cutaneous innervation is made possible by the action of specific sensory fibers located on the skin, as well ...
English: A diagram showing human dermatomes, i.e., skin regions with respect to the routing of their afferent nerves through the spinal cord. Svenska: Människans dermatom, sensoriska zonindelning. Date
Similarly a dermatome is an area of skin that a single nerve innervates with sensory fibers. Myotomes are separated by myosepta (singular: myoseptum ). [ 2 ] In vertebrate embryonic development , a myotome is the part of a somite that develops into muscle.
The notochord and the neural tube activate the protein SHH, which helps the somite to form its sclerotome. The cells of the sclerotome express the protein PAX1 that induces the cartilage and bone formation. The neural tube activates the protein WNT1 that expresses PAX 2 so the somite creates the myotome and dermatome.
Scleraxis expression will be seen throughout the entire sclerotome (rather than just the sclerotome directly anterior and posterior to the myotome) with an overexpression of FGF8, demonstrating that all sclerotome cells are capable of expressing scleraxis in response to FGF signaling. While the FGF interaction has been shown to be necessary for ...