Final answer:
The thyroid gland can protrude out and rise into the neck when it becomes abnormally enlarged, a condition known as goiter.
Step-by-step explanation:
The structure that protrudes out and rises into the neck when it is too big is the thyroid gland. This condition is known as a goiter, which is an abnormal enlargement of the thyroid gland. The thyroid gland, located in the neck just below the larynx and in front of the trachea, can swell due to various thyroid disorders, including iodine deficiency, thyroid tumors, excess of thyroid-stimulating hormone (TSH), or the presence of thyroid-stimulating immunoglobulins (TSIs), which can lead to exophthalmic goiter, a related condition with symptoms including bulging eyes. Goiter can be felt under the skin of the neck and sometimes seen as a bulge.