Question 1

Which of the following best describes the main difference between the nervous system and the endocrine system in terms of response duration and signaling distance?

Accepted Answer

The nervous system initiates rapid, short-duration responses that act over very short distances, while the endocrine system initiates slow, long-duration responses that act over long distances.

Question 2

A patient presents with persistently low levels of a hormone. Which cellular adaptation is most likely to occur in the target cells?

Accepted Answer

Up-regulation of hormone receptors

Question 3

Which of the following hormones is synthesized from cholesterol and is lipid-soluble, allowing it to cross the plasma membrane?

Accepted Answer

Cortisol

Question 4

Which mechanism is used by most amino acid-based hormones (except thyroid hormone) to exert their effects on target cells?

Accepted Answer

Second-messenger systems involving membrane receptors

Question 5

A patient is experiencing symptoms of hypercalcemia. Which hormone is most likely to be elevated, and what is its primary effect?

Accepted Answer

Calcitonin; inhibits osteoclast activity and promotes Ca$^{2+}$ uptake into bone

Question 6

Which of the following equations correctly represents the conversion of ATP to cAMP in the second messenger system?

Accepted Answer

$ATP \rightarrow cAMP + PP_i$

Question 7

Which hormone is secreted by the adrenal cortex and is primarily responsible for regulating blood sodium and potassium levels?

Accepted Answer

Aldosterone

Question 8

A patient with a tumor in the anterior pituitary is found to have elevated levels of TSH. Which downstream effect is most likely to occur?

Accepted Answer

Increased production of thyroid hormones (T3 and T4)

Question 9

Which of the following best explains why steroid hormones typically have a longer half-life in the bloodstream compared to peptide hormones?

Accepted Answer

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

Question 10

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

Accepted Answer

Hormone binds receptor → G protein activated → Adenylate cyclase activated → ATP converted to cAMP → Protein kinases activated

Question 11

A patient is experiencing symptoms of chronic stress. Which hormone is most likely to be elevated during the long-term stress response, and what is its primary metabolic effect?

Accepted Answer

Cortisol; increases blood glucose by promoting gluconeogenesis

Question 12

Which hormone is secreted by the pineal gland and is involved in regulating circadian rhythms?

Accepted Answer

Melatonin

Question 13

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

Accepted Answer

Insulin decreases blood glucose, while glucagon increases it.

Question 14

Which of the following is NOT a direct effect of parathyroid hormone (PTH) on target organs?

Accepted Answer

Inhibits insulin secretion from pancreatic beta cells

Question 15

Which of the following best explains the role of the hypothalamus in controlling the pituitary gland?

Accepted Answer

The hypothalamus controls the anterior pituitary via releasing and inhibiting hormones, and the posterior pituitary via neural connections.

Question 16

Which hormone is secreted by the heart in response to high blood volume and pressure, and what is its primary effect?

Accepted Answer

Atrial natriuretic peptide (ANP); increases excretion of Na$^+$ and water, lowering blood pressure

Question 17

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

Accepted Answer

Declining blood Ca$^{2+}$ levels stimulate the parathyroid glands to secrete PTH.

Question 18

Which hormone is primarily responsible for promoting the activation of vitamin D in the kidneys, leading to increased intestinal absorption of calcium?

Accepted Answer

Parathyroid hormone (PTH)

Question 19

A patient with Type 1 diabetes mellitus is unable to produce sufficient insulin. Which of the following best describes the expected effect on blood glucose levels?

Accepted Answer

Blood glucose levels will increase due to decreased glucose uptake and increased gluconeogenesis.

Chapter 16: The Endocrine System – Anatomy & Physiology Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards