1 Ghrelin is a fast-acting hormone that plays a vital role in meal initiation and contributes to weight gain. 2  Leptin mediates long-term regulation of energy balance and suppresses food intake, thereby inducing weight loss.  Both hormones can be controlled naturally, primarily though exercise and stress management.
Surgical retractors. A retractor is a surgical instrument with which a surgeon can either actively separate the edges of a surgical incision or wound, or can hold back underlying organs and tissues, so that body parts under the incision may be accessed. The two are each available in many shapes, sizes, and styles.
Self-Retaining Retractors. Retractors are used to hold an incision or wound open while a surgeon works. The retractor could also be used to hold tissues or organs out of the way during a surgery. Self-retaining retractors allow hands free operation during a surgery. Retractors with opposable blades which use a screw, ratchet or clamp to hold the tissue apart by themselves are called self-retaining retractors.