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.

Correct Answer: C

Rationale: Touch input via the integumentary system sends messages to the nervous system. The integumentary system, comprising the skin, hair, and nails, functions as a sensory organ and a protective barrier against external threats. Specialized receptors in the skin detect stimuli like pressure, temperature, and pain, transmitting signals to the nervous system for interpretation. This communication enables the perception of touch and is vital for sensory processes, showcasing the interconnectedness between the integumentary and nervous systems. Choices A, B, and D are incorrect because the integumentary system primarily interacts with the nervous system through sensory input and communication of stimuli, rather than heat removal, nutrient circulation, or affecting skin color and texture based on nervous system messages.

Correct Answer: A

Rationale: The skeletal system is primarily responsible for storing minerals in the body. Bones serve as a storage site for essential minerals such as calcium and phosphorus, which are important for various bodily functions including bone strength, muscle contraction, and nerve signaling. The minerals stored in bones can be released into the bloodstream as needed to maintain optimal mineral levels in the body. The endocrine system is responsible for hormone regulation, not mineral storage. The lymphatic system is involved in immune function and fluid balance, not mineral storage. The cardiovascular system is responsible for circulating blood throughout the body, not storing minerals.

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.

Correct Answer: C

Rationale: The intercostal muscles located between the ribs play a crucial role in respiration by aiding in the enlargement and reduction of the space in the thorax. During inspiration, these muscles contract, lifting the rib cage, which increases the volume of the thoracic cavity and allows the lungs to expand and fill with air. This process directly relates to the expansion of the thorax rather than protecting bronchioles and alveoli (Choice A), signaling intra-alveolar pressure changes (Choice B), or maintaining the separation between pleurae (Choice D). Therefore, the correct answer is C.