And all of your epithelial tissues are avascular — meaning they don't have a blood supply.

你所有的上皮组织都是无血管的，这意味着们没有血液供应。

Later, they get stuck in other bones, causing sickle cell pain crises or avascular necrosis of the bone.

，们嵌顿在其骨骼，造成镰疼痛危象或骨骼无血管坏死。

They can also cause avascular necrosis of certain regions within the bone, if the tumor impinges on a major blood vessels.

如果肿瘤侵犯到主要血管，骨肿瘤还会造成骨骼内某些区域无血管坏死（AVN）。

Most cartilage is avascular, for example, meaning it has no blood vessels; while other types of connective tissue, like the dense irregular tissue in your skin, is brimming with blood vessels.

例如，大多数软骨是无血管的，这意味着没有血管；而其他类型的结缔组织，如皮肤中致密的不规则组织，充满了血管。