Flashcards in Axial Skeleton Development Deck (70)
somitomeres arise from where
what day do the somitomeres arise ?
day 18 approx
What day to the somites begin to form ?
somites differentiate into what ?
sclerotome and dermomyotome
how many occpipital, cervical, thoracic, lumbar, sacral and coccygeal somtes are there respectivelty
the ____________occipital somite and the cranial portion of the ________ cervical sclerotome help form the base of the occpital bone
how is the atlas formed ?
caudal half of the first cervical scleroome and the cranial half of the second cervical sclerotome
how is the first thoracic vertebrae formed ?
caudal half of the 8th cervical and the cranial half of the first thoracic sclerotome
the ribs form from
sterum forms from
where do the intervertebral disks arise from ?>
a thin layer of mesenchymal cells between the cranial and caudal portions of the original sclerotome
notochord gives rise to what part of the interertebral disks
annulus fibrosis develops from what /
abnormal curvature because of improper fusion or formation of the vertebral column
sucken in chest, deformity in sternal bone
abnormal fusion resulting from misformed vertebrae
spina bifida occulta
incomplete neural disk usually asymptomatic and accomapnied by a patch of hair over the lesion
Klippel Feil syndrome
short neck from reduced number of cervical vetebrae
remnants of notochord may give rise to malignant tumors that invade bone they develop at the base of the skull in the lumbar region
vast majority of skeletal muscles are derived from what
muscles of the head arise from
muscles of the tonque, torso and limbs arise from
extrinsic muscles of eye develop from
dorsal part of the myotome is formed by _____________ which migrate farther to form _____________ muscles
primaxial muscle cells, epaxial (instrinisc)
lateral part of myotome is formed by _____________ muscle cell precursors and gives rise to ____ muscles
conditions that result in weakness and muscle atrophy
congentical absence of pectoralis major
contracture or shortening of the sternocleidomastoid