Axial Skeleton Development Flashcards Preview

Embryology > Axial Skeleton Development > Flashcards

Flashcards in Axial Skeleton Development Deck (70)
Loading flashcards...
1

somitomeres arise from where

paraxial mesoderm

2

what day do the somitomeres arise ?

day 18 approx

3

What day to the somites begin to form ?

day 20

4

somites differentiate into what ?

sclerotome and dermomyotome

5

how many occpipital, cervical, thoracic, lumbar, sacral and coccygeal somtes are there respectivelty

4,8,12,5,5,8-10

6

the ____________occipital somite and the cranial portion of the ________ cervical sclerotome help form the base of the occpital bone

fourth, first

7

how is the atlas formed ?

caudal half of the first cervical scleroome and the cranial half of the second cervical sclerotome

8

how is the first thoracic vertebrae formed ?

caudal half of the 8th cervical and the cranial half of the first thoracic sclerotome

9

the ribs form from

paraxial mesoderm

10

sterum forms from

somatic mesoderm

11

where do the intervertebral disks arise from ?>

a thin layer of mesenchymal cells between the cranial and caudal portions of the original sclerotome

12

notochord gives rise to what part of the interertebral disks

nucleus pulposis

13

annulus fibrosis develops from what /

sclerotome

14

scoliosis

abnormal curvature because of improper fusion or formation of the vertebral column

15

pescavatum

sucken in chest, deformity in sternal bone

16

hemivertebrae

abnormal fusion resulting from misformed vertebrae

17

spina bifida occulta

incomplete neural disk usually asymptomatic and accomapnied by a patch of hair over the lesion

18

Klippel Feil syndrome

short neck from reduced number of cervical vetebrae

19

chordoma

remnants of notochord may give rise to malignant tumors that invade bone they develop at the base of the skull in the lumbar region

20

vast majority of skeletal muscles are derived from what

paraxial mesoderm

21

muscles of the head arise from

somitomeres

22

muscles of the tonque, torso and limbs arise from

somites

23

extrinsic muscles of eye develop from

pre-optic somites

24

dorsal part of the myotome is formed by _____________ which migrate farther to form _____________ muscles

primaxial muscle cells, epaxial (instrinisc)

25

lateral part of myotome is formed by _____________ muscle cell precursors and gives rise to ____ muscles

abaxial, hypaxial

26

muscle dystrophies

conditions that result in weakness and muscle atrophy

27

accessory muscles

rectus sternalis

28

polan anomaly

congentical absence of pectoralis major

29

congenital torticollis

contracture or shortening of the sternocleidomastoid

30

slcerotome

gives rise to mesenchymal clles