thickening of a clump of cells on both sides of the embryo midline (next to notochord). These clumps form as pairs in a cranial (forms first) to caudal direction.
1 of 19
Day 20
When the first somite pair forms.
2 of 19
Week 5
Somite formation is complete (42-44 pairs); this is roughly one pair per vertebrae. Although, the occipital (most cranial) and coccygeal (most caudal) degenerate and fuse, leaving 37 mature somites.
3 of 19
Sclerotome
The cells of a somite differentiate into skeleton stem cell pools
4 of 19
Dermomyotome
The cells of a somite differentiate into several stem cell pools. this then becomes dermotome (dermis) and myotome (muscle).
5 of 19
Sclerotome
The part of a mesodermal somite contributing to the development of the vertebrae and ribs. Cells of the sclerotome undergo EMT to surround the notochord. Generates the axial skeleton.
6 of 19
Axial Skeleton
Bones including the vertebrae, sacrum, coccyx, ribs, and sternum.
7 of 19
Syndetome
subdomain that occupies the dorso-lateral portion of somite and is comprised of tendon progenitor cells.
8 of 19
Myotome
Releases muscle precursors that travel to the limb buds. Myoblasts fuse into mature multi-nucleated myotubes. Only the mature fibres can contract.
9 of 19
Dermotome
Generates the dermis of the head and trunk of the body. The “skin” is a mixture of ectoderm: epithelium, nails, hair and glands, and mesoderm leads to the creation of the dermis, connective tissue and blood vessels.
10 of 19
Dermatome
Area of skin that is mainly supplied by a single spinal nerve. Each of these nerves relays sensation from a particular region of skin to the brain.
11 of 19
Chicken Pox Virus
Dormant in the dorsal root ganglia of the spine (after recovery). This latent infection can become re-activated in later life as the virus follows the spinal nerve to the skin, causing shingles. Normally only affects one dermatome.
12 of 19
Skeletal Muscle
Attached to bone via tendons and provides the force needed to move the body. The somite myotome forms two populations the ventrolateral and dorsomedial edge. Ventrolateral forms hypaxial muscle and dorsomedial forms epaxial muscle.
13 of 19
Limb (skeletal) Muscle
Myotome precursors migrate into the limb and combine to generate specific muscle masses. Spinal nerves migrate with the myotome from their somite level. This will form discrete dermatomes in the limb. Limbs can move from 10-11 weeks.
14 of 19
Head Muscle
The cranial nerves are present first, the myoblasts therefore follow connective tissue instead. Lateral plate mesoderm and neural crest also generate muscle in the head. Somitomeres do not completely segment
15 of 19
Smooth Muscle
Involuntary muscle and originates from the splanchnic mesoderm (not paraxial mesoderm). This splanchnic mesoderm develops near their future organ. Developing blood vessels surround the splanchnic mesoderm to receive their future muscle
16 of 19
Cardiac Muscle
Comes from the splanchnic mesoderm (this surrounds the developing heart tube. Does not form multinucleated fibres (the contraction is co-ordinated with intercalated discs). At day 22, the cardiac tube will begin to contract.
17 of 19
Duchenne Muscular Dystrophy
Most common (1/5000 males), where a mutant protein causes mitochondrial death and eventually muscle cell death. Trouble walking between ages 1-3, wheelchair needed from age 8 and average life expectancy 26.
18 of 19
ALS
Death of voluntary muscle that contracts the skeletal muscle, as these muscles gradually weaken .This will cause movement and speaking difficulties, as well as eventual difficulty in breathing. 5-10% of cases inherited.
19 of 19
Other cards in this set
Card 2
Front
When the first somite pair forms.
Back
Day 20
Card 3
Front
Somite formation is complete (42-44 pairs); this is roughly one pair per vertebrae. Although, the occipital (most cranial) and coccygeal (most caudal) degenerate and fuse, leaving 37 mature somites.
Back
Card 4
Front
The cells of a somite differentiate into skeleton stem cell pools
Back
Card 5
Front
The cells of a somite differentiate into several stem cell pools. this then becomes dermotome (dermis) and myotome (muscle).
Comments
No comments have yet been made