Question

what does thyroid - stimulating hormone (tsh or thyrotropin) target?
hypothalamus
posterior pituitary (neurohypophysis)
anterior pituitary (adenohypophysis)
thyroid gland

Explanation:

Thyroid - stimulating hormone (TSH) is secreted by the anterior pituitary. Its main function is to act on the thyroid gland. It stimulates the thyroid gland to produce and secrete thyroid hormones (such as thyroxine). The hypothalamus secretes thyrotropin - releasing hormone which acts on the anterior pituitary. The posterior pituitary stores and releases hormones like oxytocin and antidiuretic hormone that are produced in the hypothalamus. The anterior pituitary produces TSH, but TSH itself targets the thyroid gland.

Answer:

Thyroid gland