Development of the Muscular System

Question 1

paraxial mesoderm derivative

Answer 1

somite - somitic**
form sclerotome - cartilage
myotome - skeletal muscle
dermatome - dermis/some skeletal muscle

Question 2

muscles of the limb are derived from

Answer 2

lateral plate mesoderm

Question 3

somite structures established by the end of

Answer 3

week 3

Question 4

somites are composed of cell types:

Answer 4

dermomyotome

sclerotome

Question 5

syndetome location and derivatives

Answer 5

between the sclerotome and myotome

forms the tendons

Question 6

myotome derivatives

Answer 6

epimere - deep epaxial muscles (erector spinae and transversospinalis)
hypomere - hypaxial muscles (lateral and ventral body wall)

Question 7

sclerotome cells appear in

Answer 7

the fourth week on either side of the notochord

give rise to the IV disc

Question 8

portions of the notochord trapped by the sclerotome cells as they become IV discs becomes known as

Answer 8

nucleus pulposa

Question 9

sclerotome cells become reorganized into three sturctures

Answer 9

ventral cells - vertebral body
dorsal cells - vertebral arch and spine
lateral cells - vertebral transverse processes and ribs

Question 10

ribs devleop from

Answer 10

costal processes

Question 11

hox genes code for

Answer 11

vertebrae identity

have nested pattern of expression boundaries along cranial-caudal axis

Question 12

sternal bars

Answer 12

fuse during 10th week to form cartilaginous models fo the manubrium, sternebrae and xiphoid process