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Chapter 45. Hormones and the Endocrine System. Questions prepared by William Wischusen Louisiana State University John Lepri University of North Carolina, Greensboro. All hormones a) are lipid-soluble molecules. b) are protein molecules.
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Chapter 45 Hormones and the Endocrine System Questions prepared by William WischusenLouisiana State University John LepriUniversity of North Carolina, Greensboro
All hormones • a) are lipid-soluble molecules. • b) are protein molecules. • c) elicit the same biological response from all of their target cells. • d) are carried to target cells in the blood. • e) are produced by endocrine glands.
Nitric oxide and epinephrine • a) are both involved in the "fight-or-flight" response. • b) bind the same receptors. • c) both function as neurotransmitters. • d) both cause a reduction in the blood levels of glucose. • e) both function as steroid hormones.
Organ X produces hormone A, whichstimulates target cells Y to produce product Z. Negative-feedback regulation is best represented by observing that • product Z does not affect X’s production of A. • product Z stimulates Y’s production of Z. • source Y runs out of substrates to make Z. • source X has receptor proteins for Z.
Thyroxine hormones exert negative feedback on the production of thyroid stimulating hormone (TSH), as best exemplified by • I. • II. • III. • IV. Thyroxines
Hormones are transported throughout the circulatory system, but they affect only specific tissues or cells because • only the capillaries at the target will let the hormones out of the blood. • only the target cells have receptors for the hormone. • the nontarget tissues catabolize or destroy the hormones. • the hormones know where their targets are located.
Epinephrine causes the constriction of some blood vessels and the dilation of others because • the target cells have different receptors for the same hormone with different signal transduction pathways. • the vasoconstriction targets are incapable of vasodilation. • the target cells have the same receptor and the same signal transduction pathway. • the hormone is able to enter the cytosol of the vasodilation targets but not the vasoconstriction targets.
Thyroid hormones exert negative-feedback effects at all levels of the hypothalamic-pituitary-thyroid gland axis, so we should expect to find thyroid hormone receptors at • the hypothalamus. • the anterior pituitary gland. • the targets of thyroid hormones throughout the body. • all of the above.
Oxytocin, the milk-release hormone secreted from nerve endings (axon terminals) in the posterior pituitary gland, is synthesized in • the anterior pituitary gland. • the hypothalamus. • the mammary glands. • the posterior pituitary gland.
The role of the pancreas as an endocrine gland that mediates glucose homeostasis is of great importance to health, but a patient whose pancreas has been surgically removed also loses • the body’s source of epinephrine. • the body’s source of growth hormones. • the body’s source of most of its digestive enzymes. • the ability to coordinate swallowing and breathing.
In the chemical communication system of the developing insect, the larval forms are most likely to persist in those individuals that have high levels of • juvenile hormone. • ecdysteroid hormones. • prothoraciotropic hormone.
The gas that causes vasodilation by relaxing vascular smooth muscle, thus enabling male sexual function, is • carbon dioxide. • nitric oxide. • carbon monoxide. • oxygen. • nitrogen.
