Peptide Hormone Activity Explain how two peptide hormones as structurally similar as oxytocin and vasopressin can have such different effects.

Which hormone influences a person’s rate of metabolism? a. PTH $\hspace{1.5cm}$ c. thyroxine b. aldosterone $\hspace{0.5cm}$d. calcitonin

What do steroid and peptide hormones typically have in common?

Explain the cascade effect for the second-messenger model of hormone action. Does the second-messenger amplification produce a slow or rapid response?

Suppose you are hiking in the Alaskan wilderness when your path crosses that of a bear. What hormone is responsible for your immediate response?

The hormone commonly referred to as adrenaline is secreted by which of the following? A pineal gland, B. adrenal cortex, C. pancreas, D. none of the above.

Roughly 12,000 Americans are diagnosed with thyroid cancer every year, which accounts for 1% of all cancer cases. It occurs in women three times as frequently as in men. Fortunately, thyroid cancer can be treated successfully in many cases with radioactive iodine, or I-131. This unstable form of iodine has a half-life of 8 days and is given in small doses measured in millicuries.

How long does it take the amount of I-131 to reach 10% of the initial dose?

Determine the isotope produced in the beta decay of iodine-131, an isotope used to check thyroid-gland function.

$$^{131}_{53} \mathrm{I} \longrightarrow_{\mathrm{Z}}^{\mathrm{A}} \mathrm{X}+_{-1}^{0} e$$

Given the description, write the abbreviation for the hormone. Fill in the blank.

Helps distinguish corticotropin pituitary tumors from adrenal gland tumors.________________

Stomata close in response to bacterial infection. Why is this response a mechanism of defense for the plant? Which hormone is most likely to mediate this response?

Predict some consequences of trying to use a skin patch to administer insulin, a protein hormone, to a person who has diabetes mellitus.

Answer the following question to test your understanding of the preceding section:
Why does a lack of dietary iodine lead to TSH hypersecretion? Why does the thyroid gland enlarge in endemic goiter?

A decrease in the level of which hormone releases seeds from dormancy? a. abscisic acid, b. cytokinin, c. ethylene, d. gibberellic acid.

**Match the endocrine gland with its location. ** adrenal cortex adrenal medulla ovary pancreas parathyroid pituitary (hypophysis) testis thyroid

outer section of gland above each kidney _____________________________