which organ system is primarily responsible for regulating electrolytes

HESI A2

HESI A2 Anatomy and Physiology Practice Test

1. Which organ system is primarily responsible for regulating electrolytes?

A. The endocrine system
B. The urinary system
C. The lymphatic system
D. The nervous system

Correct answer: B

Rationale: The urinary system, specifically the kidneys, is primarily responsible for regulating electrolytes in the body by filtering and excreting excess electrolytes, such as sodium, potassium, and chloride, through urine. The kidneys play a crucial role in maintaining the body's electrolyte balance, which is essential for various bodily functions and overall health. The endocrine system regulates hormones, the lymphatic system is involved in immunity, and the nervous system controls communication in the body. Therefore, the correct answer is B, the urinary system, as it directly handles electrolyte regulation by adjusting their excretion levels.

2. What is the first step in pulmonary circulation?

A. Blood moves toward the heart through the pulmonary veins.
B. The pulmonary artery carries blood from the heart to the lungs.
C. Carbon dioxide is exchanged for oxygen.
D. Oxygenated blood moves through the aorta.

Correct answer: B

Rationale: The correct answer is B: The pulmonary artery carries blood from the heart to the lungs. The first step in pulmonary circulation involves the right ventricle of the heart pumping deoxygenated blood into the pulmonary artery. The pulmonary artery then carries this deoxygenated blood from the heart to the lungs for oxygenation. This step is crucial for the exchange of carbon dioxide for oxygen to occur in the lungs, facilitating the oxygenation of blood. Choices A, C, and D are incorrect because they do not represent the initial step in pulmonary circulation. Option A refers to blood moving away from the heart, option C describes the gas exchange process that occurs in the lungs but not as the first step, and option D mentions oxygenated blood moving through the aorta, which happens after oxygenation in the lungs.

3. Which mineral is important for the formation of red blood cells?

A. Selenium
B. Calcium
C. Magnesium
D. Copper

Correct answer: D

Rationale: Copper is crucial for the formation of red blood cells as it is a component of enzymes involved in the production of hemoglobin. Hemoglobin, the protein in red blood cells responsible for transporting oxygen throughout the body, requires copper for its synthesis. A deficiency in copper can result in anemia due to insufficient production of red blood cells. Selenium, calcium, and magnesium do not play a direct role in red blood cell formation, making them incorrect choices for this question.

4. What is a primary function of the skeletal system?

A. Production of red blood cells
B. Support and protection
C. Secretion of hormones
D. Regulation of body temperature

Correct answer: B

Rationale: The correct answer is B: Support and protection. The primary functions of the skeletal system include providing structural support to the body and protecting internal organs. While the skeletal system also plays a role in hematopoiesis (production of blood cells) and stores minerals, its main function is to support the body's framework and protect vital organs. Choices A, C, and D are incorrect as they do not directly relate to the primary functions of the skeletal system.

5. How does the endocrine system work with the reproductive system?

A. The reproductive system transforms minerals into useful nutrients.
B. The endocrine system determines the sex of the embryo.
C. The reproductive system controls the growth of secondary sex organs.
D. The endocrine system produces chemicals that regulate sexual function.

Correct answer: D

Rationale: The correct answer is D. The endocrine system plays a vital role in the regulation of sexual functions within the reproductive system. It produces hormones that are responsible for various functions, such as the development of secondary sex characteristics, production of gametes (sperm and egg cells), and the regulation of the menstrual cycle. These hormones are crucial for the proper functioning and coordination of the reproductive system, ensuring the successful reproduction and maintenance of reproductive health. Choices A, B, and C are incorrect because the reproductive system is not primarily responsible for transforming minerals into nutrients, determining the sex of the embryo, or controlling the growth of secondary sex organs. These functions are mainly regulated by the endocrine system in coordination with the reproductive system.