True or False: In hormone systems, negative feedback occurs when the presence of a hormone inhibits release of the hormone.

The body is able to maintain a relatively constant level of thyroid hormone in the blood because

a. Thyroid hormone stimulates the pituitary to secrete thyroid-stimulating hormone (TSH).

b. Thyroid hormone inhibits the secretion of TSH-releasing hormone (TRH) from the hypothalamus.

c. TRH inhibits the secretion of thyroid hormone by the thyroid gland.

d. Thyroid hormone stimulates the hypothalamus to secrete TRH.

Which of the following assertions regarding hormones is correct? Select True or False for each statement.

T/F Growth and metamorphosis are controlled by hormones.

T/F Cortisol stimulates the production of ACTH.

T/F Hormones produced by the hypothalamus are considered neurohormones.

T/F Hormonal changes during puberty and pregnancy are forms of endocrine disruption.

Which hormone is incorrectly paired with its action?

a. Oxytocin — stimulates uterine contractions during childbirth

b. Thyroxine — inhibits metabolic processes

c. ACTH — stimulates the release of glucocorticoids by the adrenal cortex

d. Melatonin — affects biological rhythms and seasonal reproduction

What do steroid and peptide hormones typically have in common?

a. Their solubility in cell membranes

b. Their requirement for travel through the bloodstream

c. The location of their receptors

d. Their reliance on signal transduction in the cell

Compare and contrast the modes of action of lipid-soluble and water-soluble hormones.

Which of the following is the most likely explanation for hypothyroidism in a patient whose iodine level is normal?

a. Greater production of T₃ than of T₄

b. Hyposecretion of TSH

c. Hypersecretion of MSH

d. A decrease in the thyroid secretion of calcitonin