Q: Negative feedback in the endocrine system is best illustrated by which sequence?

$\text{CRH (hypothalamus)} \rightarrow \text{ACTH (anterior pituitary)} \rightarrow \text{cortisol (adrenal gland)}$

Question 1

Which of the following best describes the main function of the endocrine system?

Accepted Answer

Communication and control via hormones released from endocrine glands

Question 2

Which type of chemical signaling involves hormones traveling through the blood to reach distant target cells?

Accepted Answer

Circulating (endocrine) signaling

Question 3

A hormone acts on the same cell that secreted it. What type of signaling is this?

Accepted Answer

Autocrine

Question 4

What is the effect of down-regulation of hormone receptors on a target cell?

Accepted Answer

Decreased number of receptors, reducing the cell's response to the hormone

Question 5

Which of the following is TRUE regarding water-soluble hormones?

Accepted Answer

They bind to receptors on the cell surface and use second messengers

Question 6

Which structure is the major link between the nervous and endocrine systems?

Accepted Answer

Hypothalamus

Question 7

The anterior pituitary gland secretes hormones in response to signals from which structure?

Accepted Answer

Hypothalamus

Question 8

Negative feedback in the endocrine system is best illustrated by which sequence?

Accepted Answer

$	ext{CRH (hypothalamus)} ightarrow 	ext{ACTH (anterior pituitary)} ightarrow 	ext{cortisol (adrenal gland)}$

Question 9

Which of the following would most likely initiate negative feedback to decrease hormone secretion?

Accepted Answer

An increase in blood hormone concentration

Question 10

A patient has a mutation causing their hormone receptors to be constantly up-regulated. What is the most likely consequence?

Accepted Answer

Increased cellular response to circulating hormones

Question 11

Which of the following is a correct statement about lipid-soluble hormones?

Accepted Answer

They require carrier proteins for transport in the blood

Question 12

If a hormone is released from an endocrine gland and its effects take hours to begin but last for several months, which property does this illustrate?

Accepted Answer

Slow onset and long-lasting effects

Question 13

Which of the following is NOT a stimulus that can initiate negative feedback in hormone secretion?

Accepted Answer

Mechanical stretch of muscle fibers

Question 14

A researcher injects a water-soluble hormone into a cell culture. What is the most likely mechanism of action?

Accepted Answer

Hormone binds to cell surface receptors and activates a second messenger system

Question 15

Which of the following best explains why the hypothalamus is considered the 'master regulator' of the endocrine system?

Accepted Answer

It controls the pituitary gland, which in turn regulates other endocrine glands

Question 16

A patient with excess hormone in the blood is found to have decreased receptor numbers on target cells. This is an example of:

Accepted Answer

Down-regulation

Question 17

Which of the following equations best represents the negative feedback loop involving the hypothalamus, anterior pituitary, and adrenal gland?

Accepted Answer

$	ext{CRH} ightarrow 	ext{ACTH} ightarrow 	ext{Cortisol}$

Question 18

Which of the following is a direct effect of paracrine signaling?

Accepted Answer

A hormone acts on neighboring cells without entering the bloodstream

Question 19

If the number of hormone receptors on a target cell increases, what is the expected effect on the cell's response to the hormone?

Accepted Answer

The response will increase

Question 20

Which of the following is a property of hormones released from endocrine glands?

Accepted Answer

They circulate in the blood to reach target cells

Endocrine System: Overview and the Hypothalamus-Pituitary Axis

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