Question

thyroxine, the main hormone produced by the thyroid gland:

a. regulates blood calcium levels, working to increase absorption from the gut
b. stimulates the release of several other hormones from other endocrine glands
c. triggers the release of the sex hormones in response to mating behaviour
d. regulates body metabolism, impacting digestion, muscles, brain and health

luteinising hormone is produced by the:

a. pituitary gland
b. prostate gland
c. mammary gland
d. thyroid gland

Explanation:

Analyze thyroxine function

Thyroxine (\(T_4\)) is the primary hormone secreted into the bloodstream by the thyroid gland. It plays a vital role in regulating the body's metabolic rate, which controls how cells use energy. This metabolic regulation directly impacts digestion, muscle function, brain development, and overall health. Therefore, option (d) is correct.

Evaluate other thyroxine options

• Option (a) describes calcitonin or parathyroid hormone, not thyroxine.
• Option (b) describes tropic hormones, such as those from the pituitary.
• Option (c) describes gonadotropins or hypothalamic releasing factors.

Identify luteinizing hormone source

Luteinizing hormone (LH) is a gonadotropin synthesized and secreted by gonadotropic cells in the anterior pituitary gland. This connects directly to the Endocrine System and Pituitary Hormones pathways. Therefore, option (a) is correct.

Evaluate other LH source options

• The prostate gland (b) and mammary gland (c) are exocrine target tissues/organs, not endocrine glands that produce LH.
• The thyroid gland (d) produces thyroid hormones, not gonadotropins.

Answer:

Question 1

• a. regulates blood calcium levels, working to increase absorption from the gut
• b. stimulates the release of several other hormones from other endocrine glands
• c. triggers the release of the sex hormones in response to mating behaviour
• d. regulates body metabolism, impacting digestion, muscles, brain and health (Correct answer)

Question 2

• a. pituitary gland (Correct answer)
• b. prostate gland
• c. mammary gland
• d. thyroid gland