Question 1

After a meal, blood glucose levels rise and stimulate the release of insulin. What type of stimulation is this example?
A) humoral
B) neural
C) hormonal
D) hypothalamic

Accepted Answer

This is an example of humoral stimulation, where changes in blood levels of certain ions and nutrients directly stimulate the release of hormones, such as insulin in response to increased blood glucose levels.

Question 2

David has been feeling tired lately, and after having blood work completed, it shows elevated TSH, low iodine, and low thyroid hormone levels. Predict the possible cause from the choices below.
A) David could possibly have a thyroid tumor.
B) David may have iodine deficiency that is causing his thyroid to produce too little thyroid hormone.
C) David could have a pituitary gland tumor.
D) Too little information is given to determine the cause.

Accepted Answer

The combination of elevated TSH and low thyroid hormone levels suggests that David may have an underactive thyroid. The low iodine levels also support this idea, as iodine is necessary for the production of thyroid hormone. A thyroid tumor or pituitary gland tumor would not necessarily explain all of David's symptoms and lab results. Therefore, the best choice is B, iodine deficiency causing an underactive thyroid.

Question 3

Predict which hormone would produce longer lasting effects:
A) Hormone A, which activates a G protein.
B) Hormone B, which binds to a nuclear receptor.
C) Hormone C, which stimulates the formation of a second messenger.
D) Hormone D, which activates adenylate cyclase.

Accepted Answer

Hormone B, which binds to a nuclear receptor, would produce longer lasting effects because once the hormone binds to the nuclear receptor, it initiates gene transcription that can lead to changes in protein expression and cell function that persist for a longer time period. Hormones that activate G proteins (Choice A) or stimulate formation of a second messenger (Choice C) would produce more rapid, but shorter-lived effects. Hormone D, which activates adenylate cyclase (Choice D), would produce effects that are similar to hormones that stimulate formation of a second messenger, because adenylate cyclase produces cAMP, which is a second messenger.

Quiz 17: Functional Organization of the Endocrine System

After a meal, blood glucose levels rise and stimulate the release of insulin. What type of stimulation is this example?

David has been feeling tired lately, and after having blood work completed, it shows elevated TSH, low iodine, and low thyroid hormone levels. Predict the possible cause from the choices below.

Predict which hormone would produce longer lasting effects: