Identify the vertebral curvature labeled “B” that is present at birth.

Identify the 4 fused bones labeled “A” 

Identify the air-filled cavity highlighted in red labeled “A”

Identify the entire bone pictured here.

Identify the bone marking highlighted in red labeled “B”

Identify the ridge bone marking highlighted in red labeled “A”

Identify the entire bone (left & right) highlighted in red labeled “A”

Identify the bone marking labeled “A”

Identify the bone marking labeled “A”   

Identify the entire bone (left & right) highlighted in blue labeled “B”