What is the role of a second messenger in hormone action?
it relays a hormone's message inside a target cell
Since most chemical signals are unable to pass through the plasma membrane, the cellular action they initiate results from _____.
The signal transduction pathway
What did experiments with melanocyte-stimulating hormone, a water-soluble hormone, in the skin cells of frogs reveal about hormone action?
They revealed the role of cell-surface receptors in signal transduction pathways
Ibuprofen is known for its pain-relieving and anti-inflammatory properties because it inhibits the synthesis of _____.
Which one of the following endocrine organs does not actually manufacture hormones but, rather, stores hormones produced elsewhere?
A doctor might give an expectant mother _____ to stimulate uterine contractions and induce labor.
How does the hypothalamus control the secretion of growth hormone (GH) from the anterior pituitary?
The hypothalamus produces a releasing hormone that stimulates the pituitary to secrete GH.
FSH (follicle-stimulating hormone) and LH (luteinizing hormone) are trophic hormones that are also known as _____.
Which of the following hormones specifically act(s) to trigger secretion of hormones by another endocrine gland?
adrenocorticotropic hormone (ACTH)
The mammary glands of a pregnant female will begin to produce milk in response to changes in the level of which of the following hormones?
The major tropic action of growth hormone is to signal the _____ to release _____.
liver .... insulin-like growth factors
How is the level of thyroxine in the blood regulated?
High levels of T3 and T4 inhibit the secretion of TRH and TSH.
Which disorder is correctly matched with its cause?
pituitary dwarfism ... hyposecretion of growth hormone
Which is a correct statement about the thyroid gland?
Thyroid hormones trigger the change of an aquatic tadpole into a terrestrial bullfrog.
Hyperthyroidism, typically characterized by a high metabolic rate and high blood pressure, might be expected when _____.
thyroid-stimulating hormone (TSH) concentration is high
If a diet is deficient in iodine, a goiter may form because _____.
low blood levels of T3 and T4 inhibit the negative feedback loop. An overload of TSH causes enlargement of the gland.
Every time you eat a cookie or candy bar, your blood sugar increases. This triggers an increase in the hormone _____.
Which sequence below correctly describes the maintenance of glucose synthesis?
low blood sugar, pancreatic alpha cells stimulated, glucagon released, breakdown of glycogen in target cells
Which is a true statement about the adrenal medulla?
The gland is stimulated by nerve signals carried from the brain.
Which one of the following is a problem with the long-term use of glucocorticoids, such as cortisone, to treat inflammation?
suppression of the immune system
Anabolic steroids, sometimes taken illegally by athletes and bodybuilders, are synthetic substitutes for natural _____ produced in the _____.
androgens ... gonads