Question 1

Which of the following best describes the mechanism of action for steroid hormones?

Accepted Answer

They directly activate genes by forming a hormone-receptor complex that binds to DNA.

Question 2

A patient presents with low blood calcium levels. Which hormone is most likely to be secreted in response, and what is its primary action?

Accepted Answer

Parathyroid hormone (PTH); stimulates osteoclasts to release calcium from bone

Question 3

Which of the following glands is considered a mixed gland, having both endocrine and exocrine functions?

Accepted Answer

Pancreas

Question 4

Which hormone is secreted by the pineal gland and is believed to regulate the sleep/wake cycle?

Accepted Answer

Melatonin

Question 5

Aldosterone release from the adrenal cortex is primarily stimulated by which of the following conditions?

Accepted Answer

Low sodium or high potassium levels in the blood

Question 6

Which hormone is antagonistic to insulin in the regulation of blood glucose levels?

Accepted Answer

Glucagon

Question 7

Which of the following is NOT a purely endocrine organ?

Accepted Answer

Pancreas

Question 8

Which hormone is produced by parafollicular cells of the thyroid gland and what is its effect?

Accepted Answer

Calcitonin; decreases blood calcium by promoting calcium deposition in bone

Question 9

A patient is experiencing symptoms of long-term stress. Which hormone is most likely elevated, and what is its effect on blood glucose?

Accepted Answer

Cortisol; increases blood glucose

Question 10

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 11

Which hormone is released by the posterior pituitary and acts on the kidneys to regulate water balance?

Accepted Answer

Antidiuretic hormone (ADH)

Question 12

Which of the following best explains negative feedback in hormone regulation?

Accepted Answer

Hormone release stops once an appropriate level in the blood is reached.

Question 13

Which hormone is secreted by the thymus and what is its primary function?

Accepted Answer

Thymosin; matures some types of white blood cells

Question 14

Which of the following is a correct sequence for hormonal stimulus involving the hypothalamus, pituitary, and target glands?

Accepted Answer

Hypothalamus releases hormones → anterior pituitary releases hormones → target glands release hormones

Question 15

Which of the following best describes the role of mineralocorticoids secreted by the adrenal cortex?

Accepted Answer

Regulate blood sodium and potassium levels

Question 16

A patient with damage to the anterior pituitary would most likely have deficiencies in which of the following hormones?

Accepted Answer

Growth hormone and ACTH

Question 17

Which hormone is responsible for preparing the body for 'fight or flight' and what are two of its effects?

Accepted Answer

Epinephrine; increases heart rate and dilates bronchioles

Question 18

Which of the following best describes the antagonistic relationship between calcitonin and parathyroid hormone (PTH)?

Accepted Answer

Calcitonin decreases blood calcium, while PTH increases blood calcium

Question 19

Which hormone is produced by beta cells in the pancreatic islets and what is its primary function?

Accepted Answer

Insulin; lowers blood glucose by promoting uptake into cells

Question 20

Which of the following equations best represents the homeostatic range for blood calcium levels?

Accepted Answer

$$9-11 \ \mathrm{mg}/100 \mathrm{mL}$$

Chapter 9: The Endocrine System – Anatomy & Physiology Study Notes

Study Guide - Practice Questions