Ossification centres | PGI Nov 2017 Preparations MCQ

At the time of birth all of the following ossification centres are seen except

A. Lower end of femur 
B. Upper end of humerus 
C. Calcaneum 
D. Upper end of tibia 
E. Head of humerus

Answer. (C); Calcaneum (D) ; Upper end of tibia ; (E) Head of humerus

• Primary centre of ossification for shaft of humerus appears at 8th week. Upper and lower ends are cartilaginous at birth. Three secondary centres appear at the upper end for the head, greater and lesser tubercles in first few years after birth. Four secondary centres appear at the lower end.

• Three tarsal bone ossifies at birth, They are —

Calcaneus :                   3rd month                                (begins to ossify)

Talus :                                     6th month                                (begins to ossify)

Cuboid :                                   9th month                                (begins to ossify)

• Excepting the clavicle, femur is the first long bone to ossify. It does so in cartilage. A centre in the shaft appears at 7th week of fetal life. A centre for lower end appears at the end of 9th fetal month (at birth),

• Primary centre for shaft of tibia (for ossification) appear at 8th week of fetal life. Upper end (growing end) shows a centre immediately after birth.