Thyroid gland is located just below the larynx.
Composed of two lobes connected by an isthmus.
The gland consists of numerous spherical hollow sacs
called thyroid follicles.
Follicles are lined with simple cuboidal epithelium
that are esponsible for the production of thyroid hormone.
The interior of the follicles contains colloid - a
protein rich fluid.
Between the follicles there exists group of cells
called the parafollicular cells that are responsible for production
of Calcitonin - a hormone involved in calcium and phosphate homostasis.