what are chemical messengers that control growth differentiation and the metabolism of specific target cells called
Logo

Nursing Elites

HESI A2

HESI A2 Anatomy and Physiology Practice Test

1. What are the chemical messengers that control growth, differentiation, and metabolism of specific target cells called?

Correct answer: A

Rationale: Hormones are signaling molecules produced by glands in multicellular organisms. They travel through the bloodstream to specific target cells where they regulate various physiological processes, including growth, differentiation, and metabolism. Neurons (choice B) are nerve cells that transmit nerve impulses and are not responsible for controlling growth, differentiation, or metabolism. Glands (choice C) produce and release hormones but are not the chemical messengers themselves. Second messengers (choice D) are molecules involved in intracellular signal transduction, not the primary chemical messengers controlling growth, differentiation, and metabolism. Therefore, hormones (choice A) are the correct answer as they match the description provided in the question.

2. Which is a secondary defense for the body against pathogens?

Correct answer: C

Rationale: Inflammation is a secondary defense mechanism for the body against pathogens. When tissues are injured or infected, inflammation occurs as a protective response involving increased blood flow, white blood cell migration, and tissue repair. This process helps contain and eliminate pathogens, preventing them from spreading further in the body. Tears (Choice A) are a primary defense containing lysozyme and other antimicrobial agents. Urine (Choice B) is typically considered a non-specific defense mechanism due to its flushing action in the urinary tract. Mucus (Choice D) acts as a physical barrier and traps pathogens, also considered a primary defense mechanism.

3. Which of the following is not a component of the central nervous system?

Correct answer: B

Rationale: The central nervous system comprises the brain and spinal cord, responsible for processing and transmitting information. The retina, though part of the eye, is an extension of the central nervous system. However, the heart is part of the circulatory system, responsible for pumping blood throughout the body. Therefore, the correct answer is the heart as it is not a component of the central nervous system.

4. Which hormone regulates blood sugar levels?

Correct answer: A

Rationale: Insulin is the hormone that regulates blood sugar levels by promoting the uptake of glucose into cells. It is produced by the pancreas and helps to lower blood sugar levels when they are too high. Glucagon, on the other hand, works in opposition to insulin by raising blood sugar levels when they are too low. Cortisol and thyroxine play different roles in the body and are not primarily responsible for regulating blood sugar levels.

5. What is the primary function of the integumentary system?

Correct answer: A

Rationale: The correct answer is A: Protecting the body from external damage. The primary function of the integumentary system, which includes the skin, hair, and nails, is to act as a physical barrier that protects the body from external damage such as pathogens, UV radiation, and mechanical injuries. While the integumentary system does play roles in regulating body temperature and producing vitamin D, its main and most crucial function is to provide a protective shield for the body. Choices B, C, and D are incorrect because although the integumentary system contributes to regulating body temperature and producing vitamin D, as well as housing cells involved in the immune response, its primary role is protection.

Similar Questions

What is the function of the stomach in the digestive system?
What is the role of the gallbladder in digestion?
Which organ system is primarily responsible for regulating electrolytes?
What is the primary function of the alveoli in the lungs?
Which vitamin is essential for calcium absorption?

Access More Features

HESI A2 Basic
$99/ 30 days

  • 3,000 Questions with answers
  • 30 days access

HESI A2 Premium
$149.99/ 90 days

  • Actual HESI A2 Questions
  • 3,000 questions with answers
  • 90 days access

Other Courses