Question 1

Which of the following best describes the primary function of hormones in the endocrine system?

Accepted Answer

They serve as biological messengers that regulate the metabolic activities of cells.

Question 2

Hormones are measured in extremely small quantities. If a hormone concentration is 1 nanogram per liter, how would you express this in scientific notation?

Accepted Answer

$$1 	imes 10$$^{-9}$$ g/L

Question 3

Which of the following is NOT a mechanism by which hormones alter cellular activity?

Accepted Answer

Directly synthesizing DNA

Question 4

A patient is experiencing delayed reproductive development due to a lack of thyroid hormone. This is an example of which type of hormone interaction?

Accepted Answer

Permissiveness

Question 5

Which of the following statements about steroid hormones is TRUE?

Accepted Answer

Steroid hormones diffuse easily into their target cells and bind to intracellular receptors.

Question 6

If the number of hormone receptors on a target cell increases in response to high hormone levels, this is called:

Accepted Answer

Up-regulation

Question 7

Which equation correctly represents the conversion of ATP to cAMP by adenylate cyclase in the second messenger system?

Accepted Answer

$$ATP \rightarrow cAMP + PP_i$$

Question 8

A sudden increase in blood calcium levels stimulates the release of parathyroid hormone (PTH). This is an example of which type of endocrine stimulus?

Accepted Answer

Humoral stimulus

Question 9

Which of the following is a correct statement about hormone-target cell specificity?

Accepted Answer

Target cells must have specific receptors for the hormone.

Question 10

Which of the following factors does NOT affect target cell activation by a hormone?

Accepted Answer

The size of the target cell

Question 11

Which hormone is released from the posterior pituitary and is involved in water retention by the kidneys?

Accepted Answer

Antidiuretic hormone (ADH)

Question 12

A patient with low blood sodium and high blood potassium is likely to have increased secretion of which hormone?

Accepted Answer

Aldosterone

Question 13

Which of the following best explains the antagonistic relationship between insulin and glucagon?

Accepted Answer

Insulin lowers blood glucose levels while glucagon raises them.

Question 14

Which of the following is a correct sequence of events for amino acid-based hormone action via the PIP-Calcium pathway?

Accepted Answer

Hormone binds to receptor → G protein activates phospholipase → PIP2 splits into DAG and IP3 → IP3 triggers Ca$$^{2+}$$ release

Question 15

Which of the following is NOT a major endocrine gland?

Accepted Answer

Spleen

Question 16

Which hormone is responsible for stimulating milk production in females?

Accepted Answer

Prolactin (PRL)

Question 17

Which of the following best describes the role of the hypothalamus in endocrine regulation?

Accepted Answer

It produces hormones that are stored and released by the posterior pituitary.

Question 18

Which of the following is an example of a neural stimulus for hormone release?

Accepted Answer

Sympathetic nerve fibers stimulate the adrenal medulla to secrete catecholamines.

Question 19

If a hormone is released in response to another hormone, this is called:

Accepted Answer

Hormonal stimulus

Question 20

Which of the following is a correct example of negative feedback in endocrine regulation?

Accepted Answer

Rising hormone levels inhibit further hormone release.

Endocrine System: Structure, Function, and Hormone Regulation

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