Question 1

Which of the following best describes the mechanism by which steroid hormones, such as cortisol, exert their effects on target cells?

Accepted Answer

They diffuse through the plasma membrane, bind to intracellular receptors, and regulate gene transcription.

Question 2

A patient presents with an enlarged thyroid gland (goiter) and symptoms of hypothyroidism. Which of the following is the most likely cause?

Accepted Answer

A deficiency of iodine in the diet, resulting in reduced thyroxine production and increased TSH stimulation.

Question 3

Which hormone is released by the posterior pituitary and is responsible for stimulating uterine contractions during childbirth and milk ejection during breastfeeding?

Accepted Answer

Oxytocin

Question 4

What is the primary function of insulin in the regulation of blood glucose levels?

Accepted Answer

To increase the uptake of glucose by cells and promote its storage as glycogen.

Question 5

Which of the following best explains why only certain cells in the body respond to a particular hormone?

Accepted Answer

Only those cells have the specific receptors for that hormone.

Question 6

A person with type 1 diabetes mellitus is unable to regulate their blood glucose levels because:

Accepted Answer

Their pancreas does not produce enough insulin due to autoimmune destruction of islet cells.

Question 7

Which of the following is an example of negative feedback in the endocrine system?

Accepted Answer

High blood glucose stimulating insulin release, which lowers blood glucose and inhibits further insulin secretion.

Question 8

Which hormone is primarily responsible for increasing blood calcium levels by stimulating bone resorption, intestinal absorption, and kidney reabsorption of calcium?

Accepted Answer

Parathyroid hormone (PTH)

Question 9

Which of the following best describes the action of peptide hormones such as insulin?

Accepted Answer

They bind to receptors on the cell surface, triggering a second messenger cascade inside the cell.

Question 10

A person is experiencing dehydration after running a marathon. Which hormone is released to help the body retain water, and what is its primary target organ?

Accepted Answer

Antidiuretic hormone (ADH); kidneys

Question 11

Which of the following scenarios is an example of positive feedback in hormone regulation?

Accepted Answer

Uterine contractions during childbirth stimulate more oxytocin release, which intensifies contractions.

Question 12

Which hormone is secreted by the adrenal medulla and is responsible for the 'fight or flight' response?

Accepted Answer

Epinephrine (adrenaline)

Question 13

A patient has high blood pressure due to excessive sodium retention. Which hormone is most likely being overproduced?

Accepted Answer

Aldosterone

Question 14

Which hormone is produced by fat cells and helps regulate appetite and energy balance?

Accepted Answer

Leptin

Question 15

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

Accepted Answer

It synthesizes releasing and inhibiting hormones that regulate the anterior pituitary.

Question 16

A person with a mutation that prevents the production of cyclic AMP (cAMP) in their cells would have difficulty responding to which type of hormone?

Accepted Answer

Peptide hormones that use second messenger systems

Question 17

Which hormone is released by the kidneys in response to low oxygen levels and stimulates red blood cell production?

Accepted Answer

Erythropoietin

Question 18

Which of the following is a function of the hormone melatonin, produced by the pineal gland?

Accepted Answer

Regulation of sleep-wake cycles and seasonal reproductive cycles

Question 19

Which hormone is responsible for stimulating the development of male secondary sexual characteristics and sperm production?

Accepted Answer

Testosterone

Question 20

A person is experiencing symptoms of hyperthyroidism, such as increased appetite and weight loss. Which hormone is likely being overproduced?

Accepted Answer

Thyroxine

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