What is the primary function of the digestive system?

Correct Answer: B

Rationale: The primary function of the digestive system is to break down food into smaller molecules and absorb nutrients such as vitamins, minerals, carbohydrates, proteins, and fats. These nutrients are then utilized by the body for energy, growth, and repair. The digestive system plays a crucial role in the process of extracting essential components from food and distributing them to the body's cells through the bloodstream. Choices A, C, and D are incorrect because transporting oxygen, producing hormones, and transporting blood are functions associated with other body systems like the respiratory system, endocrine system, and circulatory system, respectively, not the digestive system.

Correct Answer: B

Rationale: The small intestine is the primary site for nutrient absorption in the digestive system. It is responsible for absorbing nutrients from the digested food into the bloodstream for distribution throughout the body. Therefore, the correct function of the small intestine is to absorb nutrients. Choice A is incorrect because the gallbladder stores bile, not the small intestine. Choice C is incorrect because the digestion process primarily occurs in the stomach and small intestine. Choice D is incorrect because while the small intestine does play a role in enzyme production, its primary function is nutrient absorption.

Correct Answer: A

Rationale: The primary function of the nervous system is to transmit signals and coordinate body activities. It controls and regulates body functions by sending and receiving signals between different parts of the body, enabling responses to internal and external stimuli. This intricate network allows for communication between the brain, spinal cord, and the rest of the body, ultimately facilitating movement, sensation, thoughts, and various bodily functions. Choices B, C, and D are incorrect as they do not represent the primary function of the nervous system. Fighting infections is primarily the role of the immune system, producing hormones is the function of the endocrine system, and regulating body temperature involves mechanisms of thermoregulation within the body, not directly controlled by the nervous system.

Correct Answer: A

Rationale: The correct answer is A: 'To produce bile.' The liver's primary role in the digestive system is to produce bile. Bile is essential for emulsifying fats, aiding in their digestion and absorption in the small intestine. Choice B is incorrect because while the liver does secrete some digestive enzymes, its primary function is bile production. Choice C is incorrect because while the liver does store glucose, it is not its primary function in the digestive system. Choice D is incorrect because the liver produces bile, but it does not store it.

Correct Answer: B

Rationale: The adrenal glands function to produce hormones such as adrenaline and cortisol. These hormones play essential roles in regulating metabolism, immune response, and the body's response to stress. Therefore, the correct answer is that the adrenal glands produce hormones. Choices A, C, and D are incorrect as regulating blood sugar is primarily done by the pancreas, producing red blood cells is the function of the bone marrow, and filtering blood is carried out by the kidneys, not the adrenal glands.