PHGY 216 MODULE 1
1. What are the 6 main functions of the endocrine system?
Answer 1. Maintain constant internal environment via regulation of metabolism and H2O/electrolyte balance. 2. Adaptive
stress response. 3. Growth and development. 4. Reproduction. 5. Red blood cell production. 6. Integrating with the autonomic
nervous system in regulating circulation and digestive functions.
2. What are hormones?
Answer Chemical substances that are secreted directly into the blood at low quantities that
exert a physiological ettect at a distant target tissue.
3. What do all endocrine tissues secrete?
Answer Hormones.
4. What are the 2 major categories of hormones?
Answer 1. Hydrophilic. 2. Lipophilic.
5. Name 2 characteristics of hydrophilic hormones.
Answer 1. Highly water soluble. 2. Low lipid solubility.
6. How are hydrophilic hormones found?
,Answer They are commonly found unbound to carrier molecules within the plasma.
7. What is the structure of most hydrophilic hormones?
Answer Peptides or proteins.
8. What are the 2 major groups of hydrophilic hormones?
Answer 1. Peptide hormones. 2. Amines.
9. What are amines?
Answer Hormones based on single amino acid residues.
10. What are the 2 types of amine hormones?
Answer 1. Catecholamines (norepinephrine & epineph- rine). 2. Thyroid hormones.
11. Are thyroid hormones hydrophilic?
Answer No.
12. Name the 2 ways that catecholamines can be found.
Answer 1. Free. 2. Bound to carrier molecules.
13. What are peptide hormones synthesized and secreted by?
Answer The same cellular machin- ery that makes proteins within cells.
14. Explain the 4 step process of peptide hormone synthesis.
,Answer 1. Synthesis - large precursor proteins called preprohormones are synthesized by ER ribosomes. 2.
Packaging - processed into active hormones and packaged into secretory vesicles. 3. Storage - hormone-containing vesicles
can be stored until the appropriate signal. 4. Secretion - the appropriate signal initiates exocytosis of the vesicles.
15. Name 2 characteristics of lipophilic hormones.
Answer 1. Highly soluble in lipids. 2. Poorly soluble
in water.
16. How are lipophilic hormones transported throughout the body?
Answer By carrier mole- cules.
17. What are the 2 classifications of lipophilic hormones?
Answer 1. Amine thyroid hormones. 2. Steroid hormones.
, 18. What are all steroid hormones synthesized from?
Answer A single molecule
cholesterol.
19. What depicts which steroid hormone is produced by a particular tissue?
Answer A specific enzyme within the cell of that tissue.
20. What tissue contains the enzyme that creates cortisol?
Answer The adrenal cortex tissue.
21. Are steroid hormones stored?
Answer No, because they are lipophilic - they are released as they are synthesized.
22. What kind of hormones can interact with a receptor at its target cell?
Answer Free, unbound hormones.
23. At any given time, are 100% of steroid hormones in the blood bound to carriers?
Answer No, they are dynamically unbinding and rebinding, resulting in a small fraction of hormone that is unbound.
24. What kind of hormone is active and able to act on target cells?
Answer Unbound hormone.
1. What are the 6 main functions of the endocrine system?
Answer 1. Maintain constant internal environment via regulation of metabolism and H2O/electrolyte balance. 2. Adaptive
stress response. 3. Growth and development. 4. Reproduction. 5. Red blood cell production. 6. Integrating with the autonomic
nervous system in regulating circulation and digestive functions.
2. What are hormones?
Answer Chemical substances that are secreted directly into the blood at low quantities that
exert a physiological ettect at a distant target tissue.
3. What do all endocrine tissues secrete?
Answer Hormones.
4. What are the 2 major categories of hormones?
Answer 1. Hydrophilic. 2. Lipophilic.
5. Name 2 characteristics of hydrophilic hormones.
Answer 1. Highly water soluble. 2. Low lipid solubility.
6. How are hydrophilic hormones found?
,Answer They are commonly found unbound to carrier molecules within the plasma.
7. What is the structure of most hydrophilic hormones?
Answer Peptides or proteins.
8. What are the 2 major groups of hydrophilic hormones?
Answer 1. Peptide hormones. 2. Amines.
9. What are amines?
Answer Hormones based on single amino acid residues.
10. What are the 2 types of amine hormones?
Answer 1. Catecholamines (norepinephrine & epineph- rine). 2. Thyroid hormones.
11. Are thyroid hormones hydrophilic?
Answer No.
12. Name the 2 ways that catecholamines can be found.
Answer 1. Free. 2. Bound to carrier molecules.
13. What are peptide hormones synthesized and secreted by?
Answer The same cellular machin- ery that makes proteins within cells.
14. Explain the 4 step process of peptide hormone synthesis.
,Answer 1. Synthesis - large precursor proteins called preprohormones are synthesized by ER ribosomes. 2.
Packaging - processed into active hormones and packaged into secretory vesicles. 3. Storage - hormone-containing vesicles
can be stored until the appropriate signal. 4. Secretion - the appropriate signal initiates exocytosis of the vesicles.
15. Name 2 characteristics of lipophilic hormones.
Answer 1. Highly soluble in lipids. 2. Poorly soluble
in water.
16. How are lipophilic hormones transported throughout the body?
Answer By carrier mole- cules.
17. What are the 2 classifications of lipophilic hormones?
Answer 1. Amine thyroid hormones. 2. Steroid hormones.
, 18. What are all steroid hormones synthesized from?
Answer A single molecule
cholesterol.
19. What depicts which steroid hormone is produced by a particular tissue?
Answer A specific enzyme within the cell of that tissue.
20. What tissue contains the enzyme that creates cortisol?
Answer The adrenal cortex tissue.
21. Are steroid hormones stored?
Answer No, because they are lipophilic - they are released as they are synthesized.
22. What kind of hormones can interact with a receptor at its target cell?
Answer Free, unbound hormones.
23. At any given time, are 100% of steroid hormones in the blood bound to carriers?
Answer No, they are dynamically unbinding and rebinding, resulting in a small fraction of hormone that is unbound.
24. What kind of hormone is active and able to act on target cells?
Answer Unbound hormone.
