<P> Vertebrae are defined by the regions of the vertebral column that they occur in , as in humans . Cervical vertebrae are those in the neck area . With the exception of the two sloth genera ( Choloepus and Bradypus ) and the manatee genus , ( Trichechus ) , all mammals have seven cervical vertebrae . In other vertebrates , the number of cervical vertebrae can range from a single vertebra in amphibians , to as many as 25 in swans or 76 in the extinct plesiosaur Elasmosaurus . The dorsal vertebrae range from the bottom of the neck to the top of the pelvis . Dorsal vertebrae attached to the ribs are called thoracic vertebrae , while those without ribs are called lumbar vertebrae . The sacral vertebrae are those in the pelvic region , and range from one in amphibians , to two in most birds and modern reptiles , or up to three to five in mammals . When multiple sacral vertebrae are fused into a single structure , it is called the sacrum . The synsacrum is a similar fused structure found in birds that is composed of the sacral , lumbar , and some of the thoracic and caudal vertebra , as well as the pelvic girdle . Caudal vertebrae compose the tail , and the final few can be fused into the pygostyle in birds , or into the coccygeal or tail bone in chimpanzees ( and humans ) . </P>
<P> Vertebrae are defined by the regions of the vertebral column that they occur in , as in humans . Cervical vertebrae are those in the neck area . With the exception of the two sloth genera ( Choloepus and Bradypus ) and the manatee genus , ( Trichechus ) , all mammals have seven cervical vertebrae . In other vertebrates , the number of cervical vertebrae can range from a single vertebra in amphibians , to as many as 25 in swans or 76 in the extinct plesiosaur Elasmosaurus . The dorsal vertebrae range from the bottom of the neck to the top of the pelvis . Dorsal vertebrae attached to the ribs are called thoracic vertebrae , while those without ribs are called lumbar vertebrae . The sacral vertebrae are those in the pelvic region , and range from one in amphibians , to two in most birds and modern reptiles , or up to three to five in mammals . When multiple sacral vertebrae are fused into a single structure , it is called the sacrum . The synsacrum is a similar fused structure found in birds that is composed of the sacral , lumbar , and some of the thoracic and caudal vertebra , as well as the pelvic girdle . Caudal vertebrae compose the tail , and the final few can be fused into the pygostyle in birds , or into the coccygeal or tail bone in chimpanzees ( and humans ) . </P>
division of the back contains the neck vertebrae
division of the back contains the neck vertebrae
Cervical vertebrae
Cervical vertebrae