________ Derived from the third to fifth cervical spinal cord segments
A)Esophageal mesentery
B)Pleuropericardial membrane
C)Phrenic nerves
D)Crura of the diaphragm
E)Embryonic mediastinum

Question

Quizplus · Accepted Answer

The phrenic nerves are derived from the third,fourth,and fifth cervical segments of the spinal cord.These nerves accompany the myoblasts that grow into the developing diaphragm from the myotome regions of the cervical somites.The diaphragm descends as elongation of the neck,descent of the heart,and expansion of the pericardial and pleural cavities occur.The descent of the diaphragm,after it receives its main nerve supply,explains the rather unusual course of the phrenic nerves.

________ Derived from the Third to Fifth Cervical Spinal Cord