retractores

Retractores, in anatomical and medical usage, are structures or devices that pull back or withdraw a part of the body or tissue. The term is used for both natural biological components that cause retraction and surgical instruments designed to hold back tissues during procedures. Retraction is the act of drawing a structure away from its normal position.

In anatomy, retractors are typically muscles or muscle groups that move a part toward the midline or toward the back of the body. Examples include the rhomboid major and rhomboid minor, which retract the scapula toward the spine, and the middle fibers of the trapezius, which contribute to scapular retraction. Some animals possess retractor muscles in other regions; for instance, retractor bulbi muscles retract the eyeball into the socket in many non-human vertebrates. Retraction can be part of coordinated movements that stabilize joints or reposition limbs.

Surgical retractors are tools used to widen the operative field by holding back skin, muscle, or other tissues. They may be hand-held and operated by the surgeon or assistant, or self-retaining, using a mechanism to lock them in place. Retractors vary widely in shape and size, from simple curved blades to complex assemblies, and are selected according to the anatomy and procedure. Proper use aims to protect tissues and maintain exposure while minimizing trauma and ischemia.

The concept underlying retractors is consistent across contexts: to pull back or hold back parts of the body to facilitate access, visualization, or movement.