NEETZoologyChemical Coordination and Integration
What is the thyroid gland composed of?
Options
- ATwo lobes and an isthmus
- BThree lobes and an isthmus
- COne lobe and an isthmus
- DTwo lobes and a gland
Correct answer
A. Two lobes and an isthmus
Step-by-step solution
The thyroid gland is composed of two lobes which are located on either side of the trachea (Figure 19.3 a). Both the lobes are interconnected with a thin flap of connective tissue called isthmus. The thyroid gland is composed of follicles and stromal tissues. Each thyroid follicle is composed of follicular cells, enclosing a cavity. These follicular cells synthesise two hormones,tetraiodothyronine or thyroxine (T4) and triiodothyronine (T3).Thyroid hormones play an important role in the regulation of the basal meta