Chapter 21: Endocrine Organs
At the beginning of the chapter, the sections “Overview of the Endocrine System,” “Hormones and
their Receptors,” and “Regulation of Hormone Secretion and Feedback Mechanisms” serve as
concise reviews of concepts you learned in Bio 214 Cell & Molecular and Bio 342 Human
Physiology. It is assumed that you already know this material.
1. What are the alternative names for the anterior and posterior lobes of the pituitary gland?
2. How do the two lobes of the pituitary gland differ with respect to their developmental origin?
3. What are the three divisions of the anterior lobe? Which of these wraps around the
infundibulum?
4. What axonal tract passes through the median eminence and comprises the infundibulum?
5. What is unusual about the blood supply to the anterior pituitary?
6. What is the next set of capillaries that blood would enter after passing through capillaries in the
median eminence and infundibulum?
7. What type of capillary is typical of endocrine organs?
8. Name the four tropic hormones synthesized and secreted by the adenohypophysis.
9. Name two other anterior lobe hormones that are not considered tropic hormones.
10. What names were given to cells within the pars distalis based on their staining properties? Is
there any relationship between staining properties and secretory activities of the cells?
11. What is a chromophobe? (not explicitly defined in the text.)
12. What is the relative abundance of somatotropes, what do they secrete, and how do they stain
with H&E?
13. What is the relative abundance of lactotropes, what do they secrete, and how do they stain with
H&E?
14. What is the relative abundance of corticotropes, what is the main hormone they secrete, and
how do they stain with H&E?
15. What is the relative abundance of gonadotropes, what do they secrete, and how do they stain
with H&E?
16. What is the relative abundance of thryrotropes, what do they secrete, and how do they stain
with H&E? p. 747 5%, THS, basophilic.
17. Can a pars distalis cell secrete more than one hormone?
18. What features located where is evidence of the previous existence of Rathke’s pouch?
19. What is the function of the pars intermedia in humans?
20. Which categories of cells may be found in the pars tuberalis?
21. Where are the cell bodies of the axons of the pars nervosa and the infundibulum?
22. What is unusual about the secretory vesicles of these hypothalamohypophyseal tract neurons?
23. What are Herring bodies? What is found within them?
24. What hormones are secreted from the pars nervosa?
25. What are neurophysins and which endocrine organ has them?
26. Where are the targets cells of oxytocin?
27. What specialized cell seems to serve the role of a glial cell in the pars nervosa?
28. Explain how the pineal gland is visible on an X-radiograph of the brain and why this is of
benefit in image analysis.
29. How is the secretion of melatonin regulated by retinal activity?
30. Which gland is most likely to be responsible for the symptoms of jet lag?
31. What spherical structure is the functional unit of the thyroid gland? What is found in the center
of that structure?
32. What cell type other than follicular cells is found in the thyroid gland? What do these cells
secrete?
33. What is the action of calcitonin?
34. What is thyroglobulin? (Figure 21.16 is an excellent summary.)
35. In what form does iodine enter the basal side of follicular cells and exit the apical membrane?
36. Where does the iodination of tyrosine residues occur: intracellularly or extracellularly?
37. What cellular events in thyroid follicular cells are stimulated by TSH? How are lysosomes
involved?
38. In what form is most thyroid hormone secreted from the thyroid gland?
39. Which is the more active form of the thyroid hormones?
40. Which glands are located adjacent to or embedded in the thyroid glands?
41. Which cell type produces and secretes PTH?
42. How are the target organs of parathormone affected by the hormone?
43. How does the adrenal cortex differ from the adrenal medulla with respect to the types of
hormones secreted?
44. What are chromaffin cells and why are these cells considered to be equivalent to
postganglionic neurons of the autonomic nervous system?
45. How is the size and density of granules within the adrenal medulla correlated with the
secretions of the cells?
46. What are the 3 layers within the adrenal cortex?
47. How are cells in the outermost later arranged? What category of hormones do they secrete and
what is a specific example?
48. What stimulates secretion by the cells in the outermost layer of the adrenal cortex?
49. What is the characteristic shape and orientation of cells in the middle layer of the adrenal
cortex?
50. What class of hormones is secreted by the zona fasciculata? Give a specific example.
51. How do glucocorticoids affect the immune response and inflammatory responses?
52. What hormone stimulates secretion by cells of the zona fasciculata?
53. How can the zona reticularis be recognized histologically?
54. What does the zona reticulata secrete? Name a specific example.