semispinalis muscles

Question 1

what do semispinalis muscles span? where are they represented?

Answer 1

about 6 vertebrae

only upper half of vertebral column (T10 and superior)

Question 2

were do semispinalis thoracis and cervicis originate? insert?

Answer 2

from transverse processes of thoracic vertebrea

insert onto spines of higher vertebrae

Question 3

semispinalis capitis origin/insertion

Answer 3

tips of transverse processes of upper thoracic and lower cervical vertebrae
insert: occipital bone between the nuchal lines. large dorsal rami of spinal nerves C2 and C3 pierce this muscle.