Final answer:
Trabeculae are the structural components in the thyroid gland that outline lobules, and the gland consists mainly of thyroid follicles, which produce hormones.
Step-by-step explanation:
The structural component found within the thyroid gland that allows connective tissue to extend from the capsule and outline irregular lobules is known as trabeculae. Located in the neck, the butterfly-shaped thyroid gland is composed primarily of thyroid follicles.
These follicles are spherical structures lined with a simple cuboidal epithelium and filled with a viscous fluid known as colloid, which contains the glycoprotein thyroglobulin used for the synthesis of thyroid hormones. The follicles are responsible for the storage and release of thyroid hormones into the capillary network for transport throughout the body via the circulatory system.