A joint ring of an endoscope comprises a joint ring body including a joint ring wall having an inner surface, an outer surface, a first end surface, and a second end surface, and a first wire guide attached to the inner surface of the joint ring wall. The first wire guide includes a first wire guide body including a first wire guide wall having a third end surface and a fourth end surface. In a central axis direction of the joint ring body, at least a first portion of the first end surface and at least a first portion of the third end surface are at a first axial position and at least a first portion of the second end surface and at least a first portion of the fourth end surface are at a second axial position.

Disclosed are a connecting structure and a cat furniture item. The connecting structure includes: a first connector, configured to be fixed to one of an end surface of a column and a panel, and provided with at least one slot; a second connector, configured to be fixed to the other one, and provided with at least one block. The at least one block is configured to engage with the at least one slot respectively to achieve a detachable connection. Based on the connecting structure, the efficiency of disassembly and assembly between various components of the cat furniture item can be improved. In addition, additional fixing components such as screws are unnecessary, so that the accidental injury caused by exposure of screws can be fundamentally avoided.