Thyroid-stimulating hormone (TSH)

Definition

Thyroid-stimulating hormone (TSH) is a pituitary hormone that regulates the production of hormones by the thyroid gland. It plays a crucial role in maintaining metabolism, energy levels, and overall endocrine function.

5 Must Know Facts For Your Next Test

1. TSH is produced by the anterior pituitary gland in response to thyrotropin-releasing hormone (TRH) from the hypothalamus.
2. High levels of TSH typically indicate an underactive thyroid (hypothyroidism), while low levels suggest an overactive thyroid (hyperthyroidism).
3. TSH stimulates the thyroid gland to produce and release thyroxine (T4) and triiodothyronine (T3).
4. Negative feedback regulation involves T3 and T4 inhibiting both TRH and TSH secretion to maintain hormonal balance.
5. TSH levels are measured through blood tests to diagnose thyroid disorders.

Review Questions

• What gland produces thyroid-stimulating hormone?
• How does TSH affect the thyroid gland?
• What do high or low TSH levels indicate about thyroid function?

Related terms

Thyroxine (T4): A hormone produced by the thyroid gland that regulates metabolism.

Triiodothyronine (T3): An active thyroid hormone that plays a role in controlling metabolic rates.

Hypothalamus:

A brain region controlling various endocrine functions, including releasing TRH, which influences TSH production.