Exam 1 Axial Skeleton Flashcards
Paraxial mesoderm gives rise to what?
Axial Skeleton
Paraxial mesoderm condenses to make?
somitomeres
Somitomeres condense to make?
Somites
How many somites on formed by day 35?
42-44
Name and # of somites by region
4 occipital, 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 8-10 coccygeal
What do somites differentiate into?
sclerotomes and dermomyotomes
Are sclerotomes medial or lateral to dermomyotomes?
medial
What do sclerotomes form, and in what fashion?
vertebrae, and in caudal to cranial
What forms the nucleus pulposus?
Notocord
What forms the annulus fibrosis?
Sclerotome
Incomplete fusion of the vertebral arch leads to what?
Spina bifida occulta, sometimes will present with a hairy patch
Congenital Scoliosis is causes by what?
hemivertabrea (malformed vertebrae)
What does the dermomyotome split into?
dermatome and myotome
Muscles of the head are formed by?
somitomeres
Muscle of the torso and limbs are formed by?
somites