**Thyroid Culture from Monolayer to Closed Follicles**

Clara Spinel, Magnolia Herrera and Jhon Rivera

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/45968

**1. Introduction** 

#### **1.1. Morphology**

The thyroid is an endocrine gland formed by two lobes (Figure 1A L) located on each side of the trachea and the larynx; they are joined by an isthmus (ultimo-branchial origin) (Figure 1A clear arrow) located between the trachea's second and third cartilage rings (Figure 1A black arrow).
