The winding and curved thin collagen fibers wrapped up the cardiac myocytes and capillaries as sheath. The adjacent collagen sheaths united together and formed the compartment.

• 细胶原纤维卷曲蓬松,呈鞘状包裹心肌细胞和毛细血管,相邻的胶原鞘彼此融合形成间隔。