THE ARTERIES OF THE HUMAN THORACIC VERTEBRAE / 解剖学报

ABSTRACT

1)The arteries of the human thoracic vertebrae are studied on 14 cadavers(1 fetus,11 children and 2 adults)by dissection,clearing,and radiography.Their origins, branches,distributions,and their relations to each other on the external surfaces of the vertebrae as well as their numbers,points of entrance,and intravertebral distributions are recorded and studied. 2)All the vertebrae obtain their blood supply,directly or indirectly,from the neighbouring intercostal arteries.In addition,the upper 2 vertebrae receive also the descending branches from the inferior thyroid artery,the subclavian artery,the costo- cervical trunk or the vertebral artery,among which the branches deriving from the inferior thyroid artery occur more frequently.Both the arteries reaching the internal and external surfaces of the vertebral bodies and those distributed to the internal and external surfaces of the vertebral arches divide into ascending and descending branches(the main trunk of the intercostal artery gives rise to a number of upper and lower slender branches over the antero-lateral surfaces of the vertebral body)to supply the adjacent vertebrae.On each side(right and left)the neighbouring ascending and descending branches anastomose longitudinally,and the arteries of the same name on both sides join to form transverse anastomosis. 3)The nutrient arteries of each vertebral body form 3 groups,two of which enter the body through its right and left antero-lateral aspects respectively.The 3rd group pierces the central portion of its posterior aspect.The numbers of the arteries penetrating the antero-lateral aspect of the body vary in different ages;5—6 branches on either side of the body in 4 month fetus,reduced to 3 branches in 1—3 year old children.On the dorsal aspect,the upper ten bodies receive 2 branches each;and the lower twos,3—4 branches.In the spongy bone of the vertebral body,all the arteries of the 3 groups converge and anastomose to each other. 4)The end arteries occur only in the developing cartilaginous regions of the verte- brae.As the ossification proceeds the anastomosis develops in the spongy bone. 5)It is usually found that a nutrient artery enters the vertebral arch from behind through its superio-lateral aspect or near the base of the upper articular process of the vertebra.