Summary
Blocks of mesoderm beside the neural tube that give rise to vertebrae and muscle.
In depth
Paired segments form head to tail every 90 minutes in human embryos via a clock-and-wavefront mechanism with oscillating Notch, Wnt and FGF signals. They differentiate into dermatome, myotome and sclerotome.
Somite number is species-specific (about 40 in humans). Each somite gives vertebrae and ribs, back muscles and dermis. Somite boundaries reflect the clock.
Example: faults in the segmentation clock cause congenital vertebral malformations.
Frequently asked questions
What is Somites?
Blocks of mesoderm beside the neural tube that give rise to vertebrae and muscle.
Which area of biology covers Somites, and how advanced is it?
Somites is one of the 54 topics in Developmental Biology. It is rated Intermediate, so it suits learners who already know the core vocabulary. Related topics in this area include Gastruloids, Developmental Timing, Preimplantation Genetic Testing.
Can you give an example of Somites?
The number of somites can be used to stage embryos.
What should I learn before Somites?
Work through the Beginner topics in Developmental Biology first, such as Fertilisation, Zygote, Embryo, then return to Somites. Intermediate topics assume the Beginner vocabulary.
What topics are related to Somites?
The closest topics to Somites are Gastruloids, Developmental Timing, Preimplantation Genetic Testing, Hox Genes. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Somites?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Somites. To practise the whole of Developmental Biology, use the Developmental Biology quiz.
How is Somites different from Gastruloids?
Somites: Blocks of mesoderm beside the neural tube that give rise to vertebrae and muscle. Gastruloids: Aggregates of stem cells that self-organise to mimic early embryo axis formation. Read both side by side and note what each one explains.
How should I study Somites step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Gastruloids and explain the difference aloud. Finally, take the Developmental Biology quiz and come back to this page for any question you miss.