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.
List the different types of instruments used in orthopedic surgery and give and example. Certain types of bone retractors (e.g., Blount and Bennett retractors) are designed to be used as levers against the bone, to shift its position.