Hormones

*The answer is B.* Mineralcorticoids are synthesized in the zona glomerulosa of the adrenal cortex.

Addison disease (or adrenal cortex insufficiency) is a disorder, usually autoimmune in origin, which can cause degeneration and cell loss in the adrenal glands. Fludrocortisone is a mineralocorticoid used to treat Addison patients. Response to this drug indicates that which region of the adrenal glands was involved in the disease? a. Medulla b. Zona glomerulosa c. Zona reticularis d. Macula densa e. Zona fasciculate

*The answer is D.* Protein hormones initiate their action by binding externally to transmembrane receptor proteins in the target-cell plasma membrane. Receptors for some hormones (e.g., thyroid-stimulating hormone, serotonin, epinephrine) are linked to G proteins; other receptors, including those for insulin and growth hormone, have protein kinase activity.

Protein hormones act initially on target cells by (A) attaching to receptors on the nuclear membrane. (B) attaching to receptors in the nucleolus. (C) diffusing through the plasma membrane. (D) attaching to receptors on the plasma membrane. (E) attaching to receptors on the rough endoplasmic reticulum membrane.

*The answer is B.* Type 1 diabetes mellitus (T1DM) is a lifelong disorder of glucose homeostasis that results from the autoimmune destruction of the beta (β) cells in the islets of Langerhans. The clinical onset of T1DM often coincides with another acute illness, such as a febrile viral or bacterial infection. The disease is characterized by few (if any) functional beta cells in the islets of Langerhans and limited or absent insulin secretion. Alpha cells (choice A) secrete glucagon. Delta cells (choice C) secrete somatostatin. F cells (also termed PP cells) (choices D and E) secrete pancreatic polypeptide, which stimulates gastric chief cells and inhibits intestinal motility.

The parents of an 8-year-old boy are concerned about his weight loss following a flu-like illness. Urinalysis reveals glucosuria (glucose in the urine). His fasting blood glucose is 220 mg/dL (normal = 50 to 100 mg/dL). The child is diagnosed with diabetes mellitus type 1. Which of the following cells in the endocrine pancreas produces insulin? (A) Alpha cells (B) Beta cells (C) Delta cells (D) F cells (E) PP cells

*The answer is B.* Glucocorticoids are produced in the adrenal cortex (zone fasciculata). Adrenocorticotropic Hormone (ACTH), which is released by the anterior pituitary gland, stimulates the production of these hormones.

Which of the following accurately describes glucocorticoids? a. Include the steroid hormone aldosterone b. Are produced in response to stimulation by ACTH c. Are produced primarily by the zone glomerulosa d. Typically enhance the immune response e. Include the steroid hormone dehydroepiandrosterone (DHEA)

*The answer is B.* Chromaffin cells in the adrenal medulla synthesize and store epinephrine and norepinephrine in secretory granules, which also contain ATP, chromogranins, and enkephalins. The cortical parenchymal cells of the zona fasciculata produce glucocorticoids, and those of the zona glomerulosa produce mineralocorticoids. The cortical parenchymal cells do not store their secretory products and thus do not contain secretory granules.

Which of the following statements concerning adrenal parenchymal cells is true? (A) Those of the zona fasciculata produce androgens. (B) Those of the adrenal medulla produce epinephrine and norepinephrine. (C) Those of the zona glomerulosa produce glucocorticoids. (D) Those of the cortex contain numerous secretory granules. (E) Those of the zona reticularis produce mineralocorticoids.