Myotome vs Dermatome
Myotome is a group of tissues that develop into the body wall muscle, whereas dermatome is an area of the skin which is supplied by a single nerve from the spinal cord.
What is Myotome?
A myotome is a group of tissues formed from somites during vertebrate embryonic development. Those develop into body wall muscle. A myotome has 2 parts; a dorsal epaxial part and a ventral hypaxial part. The muscles of the thoracic and anterior abdominal walls are formed from the myoblasts from the hypaxial division. The muscles served by a single nerve root can also be called as myotomes. A particular level or segment of the spinal cord and its corresponding spinal nerve supplies each muscle. The muscle and its nerve together give rise to a myotome. Extensor muscles of the neck and trunk of mammals are formed by the epaxial muscle. For the particular purpose, it has lost the segmental character. In certain animal forms, the body musculature remains segmented as in the embryo. Fishes, salamanders, caecilians, and reptiles are good examples. They may often become folded and overlapping with epaxial and hypaxial masses divided into several distinct muscle groups. An integral part of neurological examination can be myotome testing. This is because each nerve root coming from the spinal cord supplies a specific group of muscles. Myotome distributions are neck flexion/extension, neck lateral flexion, shoulder elevation, shoulder abduction, elbow flexion/wrist extension, elbow extension/wrist flexion, thumb extension, finger abduction, hip flexion, knee extension, ankle dorsi-flexion, great toe extension, ankle plantar-flexion, and knee flexion.
What is Dermatome?
A dermatome is an area of skin to which a single spinal nerve supplies. There are eight cervical nerves, twelve thoracic nerves, five lumbar nerves and five sacral nerves in the human body. Each of these nerves transmits information from the skin to the brain. Dermatomes appear to be a stack of discs along the thorax and abdomen. Each of those dermatomes is supplied by a different spinal nerve. The pattern is quite different along the arms and legs. Along the arms and the legs, the dermatomes run longitudinally. The exact areas of innervations are unique to an individual. But the overall general pattern is similar in all humans. If more precisely described, a dermatome is an area of skin to which a sensory neuron supplies. Those sensory nerves arise from a spinal nerve ganglion. If the dermatome shows any symptoms, that may indicate that a related nerve root is involved in the particular condition. Somatic dysfunction of the spine or viral infection can be considered as good examples for this condition. Some of the spinal nerves and points that are characteristically belonging to the dermatome of each nerve are on the lateral side of the antecubital fossa, on the dorsal surface of the proximal phalanx of the thumb, on the dorsal surface of the proximal phalanx of the middle finger, on the dorsal surface of the proximal phalanx of the little finger, on the medial (ulnar) side of the antecubital fossa, at the apex of the axilla etc.
What is the difference between Dermatome and Myotome?
• Myotome is a group of tissues that develop into the body wall muscle, whereas dermatome is an area of the skin which is supplied by a single nerve from the spinal cord.