Question 1

Which of the following best describes the main difference between endocrine and exocrine glands?

Accepted Answer

Exocrine glands secrete nonhormonal substances into ducts, while endocrine glands secrete hormones directly into the blood.

Question 2

A patient presents with excessive thirst and large volumes of dilute urine. Laboratory tests reveal low levels of antidiuretic hormone (ADH). Which condition is most likely?

Accepted Answer

Diabetes insipidus

Question 3

Which hormone class is synthesized from cholesterol and is lipid-soluble, allowing it to cross the plasma membrane?

Accepted Answer

Steroid hormones

Question 4

Which of the following is a correct sequence for the cAMP second messenger system?

Accepted Answer

Hormone → G protein → Adenylate cyclase → cAMP → Protein kinase

Question 5

A water-soluble hormone binds to its receptor on the plasma membrane. What is the next immediate step in the signaling pathway?

Accepted Answer

A G protein is activated.

Question 6

Which of the following best explains why steroid hormones typically have a longer half-life in the blood than peptide hormones?

Accepted Answer

Steroid hormones are bound to plasma proteins, which protects them from rapid degradation.

Question 7

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

Accepted Answer

Low blood calcium levels stimulating parathyroid hormone (PTH) release

Question 8

A patient with an anterior pituitary tumor is found to have enlarged hands, feet, and facial bones. Which hormone is most likely hypersecreted?

Accepted Answer

Growth hormone (GH)

Question 9

Which of the following best describes the mechanism of action for lipid-soluble hormones?

Accepted Answer

They bind to intracellular receptors and directly activate gene transcription.

Question 10

Which hormone is released from the posterior pituitary in response to high blood osmolarity and acts to conserve water in the kidneys?

Accepted Answer

Antidiuretic hormone (ADH)

Question 11

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

Accepted Answer

Rising blood levels of thyroid hormone inhibit TSH release from the anterior pituitary.

Question 12

Which hormone is primarily responsible for stimulating milk production in the mammary glands?

Accepted Answer

Prolactin (PRL)

Question 13

Which of the following best describes the concept of 'up-regulation' in hormone signaling?

Accepted Answer

Target cells increase the number of receptors in response to low hormone levels.

Question 14

Which hormone is released in response to stress and acts to increase blood glucose levels by stimulating the adrenal cortex?

Accepted Answer

Adrenocorticotropic hormone (ACTH)

Question 15

Which of the following best illustrates the concept of hormone antagonism?

Accepted Answer

Insulin and glucagon have opposing effects on blood glucose levels.

Question 16

A patient has persistently high levels of a hormone, leading to a decrease in the number of its receptors on target cells. This is an example of:

Accepted Answer

Down-regulation

Question 17

Which of the following is a tropic hormone produced by the anterior pituitary that stimulates the thyroid gland?

Accepted Answer

Thyroid-stimulating hormone (TSH)

Question 18

Which hormone is released from the hypothalamus to stimulate the release of ACTH from the anterior pituitary?

Accepted Answer

Corticotropin-releasing hormone (CRH)

Question 19

Which of the following best describes the permissive effect of hormones?

Accepted Answer

One hormone cannot exert its effects without another hormone being present.

Question 20

Which hormone is responsible for triggering ovulation and stimulating the formation of the corpus luteum in females?

Accepted Answer

Luteinizing hormone (LH)

The Endocrine System: Structure, Function, and Regulation

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