Interactive Physiology Worksheet:
Endocrine System: Biochemistry, Secretion, and Transport of Hormones
1. Place the following hormones into one of the three categories of hormones (peptides, amines, or
Save your time - order a paper!
Get your paper written from scratch within the tight deadline. Our service is a reliable solution to all your troubles. Place an order on any task and we will take care of it. You won’t have to worry about the quality and deadlinesOrder Paper Now
steroids): T4 (thyroxine), estradiol, norepinephrine, insulin, aldosterone, glucagon, cortisol, growth
hormone, T3 (triiodothyronine), epinephrine, testosterone, and vasopressin (ADH).
Peptides Amines Steroids
2. Peptide hormones are synthesized as large precursor hormones called __________________.
The hormones (or prohormones) are stored in _________________ __________________ and
released from the cell by _______________________. Do peptide hormones require a carrier in the
3. Catecholamines are produced in the ____________________ of the adrenal gland and are –
classified as _________________ hormones because they are derived from __________________.
Stimulation of the chromaffin cells causes an influx of ____________________ ions, which causes the
vesicles to merge with the plasma membrane and release the hormone by ____________________.
Are catecholamines water soluble or lipid soluble? ________________________________________.
4. Thyroid hormones include two molecules called __________________ and _________________.
T3 consists of two _______________ molecules plus _____ iodine molecules and is _______________
abundant than T4. Are carriers required for the transport of thyroid hormones?
5. All steroid hormones are derived from _____________________; which steroid hormone is
produced is determined by the _________________ present in the cell. The common precursor
molecule for all steroid hormones is ______________________. Steroid hormones enter the
Page 1 of 2 BIO1014 Anatomy and Physiology II Lab
© 2013 South University
bloodstream by _______________ and ________________ require a carrier. The rate of secretion of
steroid hormones is ______________________ than that of catecholamines because steroid
hormones are not ______________________.
6. Preganglionic sympathetic fibers trigger the release of ___________________ and
____________________ (hormones) from the ________________ ________________ (gland). This is
an example of neural regulation of hormone secretion.
7. Two examples of hormonal regulation of hormone secretion include: (1) the negative feedback
of T3 and T4 to decrease ________________ levels; and (2) the negative feedback of cortisol, which
decreases both _________________ and ________________________ levels.
8. Besides increased levels of plasma glucose and amino acids (humoral regulation), increased
levels of ____________________ (hormone) and stimulation of the __________________ nervous
system also increase plasma insulin levels.
9. Some hormones are released in rhythmic 24-hour patterns known as ______________________
rhythms. _________________________ is a hormone allowing stressful stimuli to override this
pattern and increase the plasma hormone levels. In contrast, _________________ hormones (amine
hormones) are an example of large amounts of the hormones being bound to carrier proteins in the
plasma, forming a large circulating reservoir. Thus, acute changes do not produce large changes in
the plasma levels of these hormones.
10. The _____________________ and ______________________ are the major organs that
metabolize hormones. The type of hormone determines how fast they are metabolized.
__________________ and _______________________ are rapidly metabolized, while
__________________ and _____________________ take longer to metabolize.
Page 2 of 2 BIO1014 Anatomy and Physiology II Lab