Talk:Week 1 and 2 Quiz

From Embryology

{Which of the following statements about early cell division following fertilisation is/are correct: |type="[]"} +   The zygote divides to form 2 blastomeres within 24 hours of fertilisation. -   Somites contribute the body wall osteogenic, chrondrogenic and fibrogenic cells. +   The blastocyst outer cells -   Myotomes contribute the smooth muscle associated with the gastrointestinal tract wall. ||
Paraxial mesoderm forming the early somite does initially form a transient epithelial layer that covers each somite. This layer breakdown with later development, allowing the somite components to disperse. The sclerotome component of each somite pair engulf the left and right side of the notochord forming the entire axial column, that includes the vertebra and intervertebral disc (from each somite). Somatic not somitic mesoderm forms the body wall osteogenic, chrondrogenic and fibrogenic cells. Don't mix up somatic/somitic. You may have had to think about this as the dermatome, forming the dermis and fibrogenic cells, does mix with somatic mesoderm later in development, but does not contribute either osteogenic or chrondrogenic cells. Myotomes contribute the skeletal muscle not smooth muscle. The GIT smooth muscle comes from splanchnic mesoderm.