Myotomes and dermatomes Flashcards
What is neurulation?
The process that converts the neural plate ectoderm into the neural tube and neural crest cells during embryonic development. Process is induced by a mesodermal structure called the notochord (deep to the ectoderm)
What somatic structures develop from mesoderm?
Dermis, bones, ligaments, tendons, muscles
What is the role of the paraxial mesoderm during embryonic development?
Paraxial mesoderm segments to form somites.
Paraxial mesoderm is located on each side of the central cranio-caudal axis (either side of neural tube), medial to the lateral mesoderm
what does the neural tube turn into?
spinal cord and brain
what do neural crests turn into?
small clusters which form spinal ganglia (dorsal root ganglia)
What structures do somites divide into?
Dermatome, myotome and scleratome
What does the dermatome give rise to?
Dermis on the back and the limbs
What does the myotome give rise to?
skeletal muscles of the neck, trunk and limbs
What does the scleratome give rise to?
vertebrae and ribs
What structures does the lateral plate mesoderm give rise to?
Appendicular skeleton and the rest of the dermis (except face)
What structures does the ectoderm give rise to?
Neural tube, which develops into the brain, spinal cord and somatic motor neurons.
surface ectoderm, which becomes epidermis of skin.
neural crest cells, which become the spinal ganglia (cell bodies of somatosensory neurons)
In embryonic development, what is referred to as a dematome?
the part of a somites that gives rise to the dermis on the back and limbs
In an adult, what is referred to as a dermatome?
area of skin innervated by the sensory neurons from a single spinal segment/ single spinal nerve
In the embryo, what does a myotome refer to?
The part of the somite that’s gives rise to the skeletal muscles of the neck, trunk and limbs.
In the adult, what does a myotome refer to?
A collection of muscle fibres innervated by the motor neurons from a single spinal segment /nerve.
