Question

The thyroid follicles contain jelly-like material known as
A. Thyronine
B. Colloid
C. Thyroglobulin
D. Both A and B

Answer 1

The thyroid gland is a gland that is present in the neck.
This is present in the front part of the neck and is located below the larynx.

Complete answer:
There are follicle cells in these lobules which produce the thyroid hormones. The follicle contains a jelly-like matrix. This matrix is called the colloid. The thyroid hormones are responsible for regulating the metabolism of the body.
1. The thyroid contains two hormones, L-thyroxine (tetraiodothyronine, T4) and L-triiodothyronine (T3). Iodine is an indispensable component of the thyroid hormones, comprising 65% of T4’s weight, and 58% of T3’s.
2. The thyroid hormones are the only iodine-containing compounds with established physiologic significance invertebrates. Ingested iodine is absorbed through the small intestine and transported in the plasma to the thyroid, where it is concentrated, oxidized, and then incorporated into thyroglobulin (Tg) to form MIT and DIT and later T4 and T3.
3. After a variable period of storage in thyroid follicles, Tg is subjected to proteolysis and the released hormones are secreted into the circulation, where specific binding proteins carry them to target tissues.
4. The production of thyroid hormones is based on the organization of thyroid epithelial cells in functional units, the thyroid follicles.
5. Thyroid hormone synthesis is dependent on the cell polarity that conditions the targeting of specific membrane protein, either on the external side of the follicle (facing the blood capillaries) or on the internal side (at the cell-lumen boundary) and on the tightness of the follicle lumen that allows the gathering of substrates and the storage of products of the reactions.
6. Too much iodine increases the incidence of iodine-induced hyperthyroidism, autoimmune thyroid disease, and perhaps thyroid cancer. Iodide supply of follicular lumen involves a two-step transport process: The active transport across the basolateral plasma membrane of thyrocytes by NIS and passive transport across the apical plasma membrane.

So, the correct answer is “Option B ”.

Note: Internalized Tg molecules that are conveyed to lysosome compartments are subjected to diverse hydrolytic reactions leading to the generation of free thyroid hormones and to complete degradation of the protein.