Correct Answer: B

Rationale: A transverse section, also known as a cross-section, divides the body into upper and lower regions. This type of section cuts across the body horizontally, creating a division between the superior (upper) and inferior (lower) portions of the body. Choice A is incorrect as dividing the body into right and left regions is typically done by a sagittal section. Choice C is incorrect as dividing the body into front and back regions is usually achieved by a frontal section. Choice D is incorrect as it refers more to the relationship between dorsal and ventral cavities rather than the actual division of the body.

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 corpus callosum is a structure in the brain that enables communication between the two hemispheres. It allows for the transfer of various types of information, such as motor, sensory, and cognitive, between the left and right brain hemispheres, aiding in overall brain function and integration of tasks. Choices B, C, and D are incorrect as they do not involve the specific brain structures connected by the corpus callosum.

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.

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.