Question 1

Which of the following best describes the difference between paracrine and endocrine signaling as shown in the first image?

Accepted Answer

Paracrine signaling acts on nearby cells by diffusion, while endocrine signaling involves hormones traveling through the bloodstream to distant target cells.

Question 2

Cytokines, as shown in the second and third images, are primarily involved in which type of signaling?

Accepted Answer

Paracrine signaling

Question 3

Nitric oxide (NO), as depicted in the fourth and fifth images, is a key signaling molecule in which physiological systems?

Accepted Answer

Cardiovascular, nervous, and immune systems

Question 4

Which of the following best explains why a hormone can have different effects on different target cells, as shown in the sixth image?

Accepted Answer

Different target cells have different receptors or signal transduction pathways for the same hormone.

Question 5

Which of the following is a correct sequence of events in a typical signal transduction pathway, as illustrated in the tenth and eleventh images?

Accepted Answer

Reception → Transduction → Response

Question 6

Which type of hormone receptor is most likely to be found inside the cell, as shown in the twelfth and thirteenth images?

Accepted Answer

Receptors for lipid-soluble hormones

Question 7

The fifth image shows a signaling pathway involving NO and cGMP. Which enzyme is responsible for converting GTP to cGMP in this pathway?

Accepted Answer

Soluble guanylyl cyclase (sGC)

Question 8

Which of the following best describes the role of secondary messengers such as cAMP and Ca$$^{2+} in $$signal transduction pathways?

Accepted Answer

They amplify the signal inside the cell, leading to a larger cellular response.

Question 9

Which of the following is a correct example of negative feedback regulation in hormone signaling?

Accepted Answer

The release of thyroid hormone inhibits further release of TRH and TSH when thyroid hormone levels are sufficient.

Question 10

Which hormone is released by the posterior pituitary and is involved in milk release during breastfeeding, as shown in the study materials?

Accepted Answer

Oxytocin

Question 11

Which of the following best describes the function of tropic hormones released by the anterior pituitary?

Accepted Answer

They regulate the function of other endocrine glands.

Question 12

A patient has low blood calcium levels. Which hormone is likely to be secreted to restore homeostasis, and what is one of its effects?

Accepted Answer

Parathyroid hormone (PTH); stimulates Ca$$^{2+}$$ release from bones

Question 13

Which of the following best explains why individuals with Type I diabetes mellitus have elevated blood glucose levels?

Accepted Answer

They have a deficiency of insulin production.

Question 14

Which hormone is primarily responsible for stimulating the development of female secondary sex characteristics?

Accepted Answer

Estrogen

Question 15

Which of the following is a correct example of a hormone acting through a G protein-coupled receptor (GPCR) and a secondary messenger?

Accepted Answer

Epinephrine binding to its receptor, activating adenylyl cyclase, and increasing cAMP levels

Question 16

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

Accepted Answer

It integrates nervous and endocrine signals and regulates the pituitary gland.

Question 17

Which of the following is a correct sequence of hormone release in the regulation of thyroid hormone levels?

Accepted Answer

TRH → TSH → Thyroid hormone

Question 18

Which hormone is released by the pancreas in response to high blood glucose levels, and what is one of its effects?

Accepted Answer

Insulin; stimulates body cells to take up more glucose

Question 19

Which of the following best describes the effect of epinephrine on blood vessels supplying skeletal muscle versus those supplying the intestines?

Accepted Answer

It causes dilation in skeletal muscle vessels and constriction in intestinal vessels.

Hormonal and Cellular Communication: Mechanisms and Pathways

Study Guide - Practice Questions

Study Guide - Flashcards