Correct Answer: B

Rationale: The lymphatic system works with the circulatory system by draining excess fluid and waste products from the spaces between cells, known as interstitial fluid. This excess fluid, now called lymph, is then transported back into the blood circulation through lymphatic vessels. This process helps maintain fluid balance in the body and supports the circulatory system in regulating blood volume and pressure. Choice A is incorrect because the circulatory system does not produce red blood cells for the lymphatic system. Choice C is incorrect as the heart does not regulate lymph production in lymph glands. Choice D is incorrect as white cells from the lymphatic system do not eliminate excess red blood cells. Therefore, the correct answer is B, as lymph draws excess fluid from the cells and deposits it into the blood vessels, aiding in maintaining proper fluid balance and supporting the circulatory system.

Correct Answer: A

Rationale: Pepsin is an enzyme produced in the stomach that is essential for breaking down proteins during digestion. It functions by breaking down large protein molecules into smaller peptides, which are further broken down into amino acids for absorption in the intestines. Therefore, option A, 'To break down proteins,' is the correct answer. Choices B, C, and D are incorrect as they do not align with the specific function of pepsin in the body.

Correct Answer: C

Rationale: The correct answer is C: The lymphatic system. Antibodies are produced by specialized white blood cells called B-lymphocytes (or B cells) in response to foreign substances known as antigens. The lymphatic system includes lymph nodes, lymphatic vessels, tonsils, thymus, and spleen, which work together to produce and store antibodies to help the body fight off infections and diseases. Choice A, the endocrine system, is incorrect because it is responsible for hormone regulation, not antibody production. Choice B, the digestive system, is incorrect because its main function is to break down food and absorb nutrients, not produce antibodies. Choice D, the nervous system, is incorrect as it is responsible for transmitting signals throughout the body and coordinating body functions, not generating antibodies.

Correct Answer: A

Rationale: The correct answer is A: Somatic. The femoral, radial, and ulnar nerves are all part of the somatic nervous system, responsible for controlling voluntary movements and sensory input. These nerves innervate muscles and skin throughout the body, allowing conscious control of movements and sensations. The somatic nervous system is distinct from the autonomic nervous system, which regulates involuntary bodily functions. Choices B, C, and D are incorrect because the autonomic nervous system (B) is responsible for involuntary functions, while the sympathetic (C) and parasympathetic (D) divisions are subdivisions of the autonomic nervous system, not the somatic nervous system.

Correct Answer: B

Rationale: The headrest on a car is designed to prevent traumatic injury by limiting hyperextension of the neck during a rear-end collision. This helps reduce the risk of whiplash and other neck injuries that may occur when the head is forcefully thrown backward. Choice A is incorrect because hyperflexion is not the primary concern in rear-end collisions. Choice C is incorrect as the headrest does not directly reduce vertebral compression. Choice D is incorrect because the headrest is not directly involved in preventing disc degeneration.