Correct Answer: D

Rationale: The correct answer is the Tympanic membrane. The tympanic membrane, also known as the eardrum, is located at the end of the ear canal and vibrates when sound waves strike it. This vibration is then transmitted to the ossicles in the middle ear, which amplify and transmit the sound to the inner ear. Choice A, the Acoustic meatus, is incorrect as it is the ear canal itself, not the structure that vibrates. Choice B, the Cochlea, is responsible for translating sound vibrations into electrical signals but is not located at the end of the ear canal. Choice C, the Eustachian tube, is responsible for equalizing pressure between the middle ear and the atmosphere and is not involved in vibration from sound waves.

Correct Answer: D

Rationale: The correct answer is the Tympanic membrane. The tympanic membrane, also known as the eardrum, is located at the end of the ear canal and vibrates when sound waves strike it. This vibration is then transmitted to the ossicles in the middle ear, which amplify and transmit the sound to the inner ear. Choice A, the Acoustic meatus, is incorrect as it is the ear canal itself, not the structure that vibrates. Choice B, the Cochlea, is responsible for translating sound vibrations into electrical signals but is not located at the end of the ear canal. Choice C, the Eustachian tube, is responsible for equalizing pressure between the middle ear and the atmosphere and is not involved in vibration from sound waves.

Correct Answer: B

Rationale: The correct function associated with the dermal layer of the skin is to provide support and structure to the skin. The dermis is the thickest layer of the skin and is responsible for maintaining the skin's integrity and firmness. Choices A, C, and D are incorrect as sensory perception, protection from UV rays, and insulation are functions associated with other layers of the skin, such as the epidermis and subcutaneous tissue.

Correct Answer: C

Rationale: The correct answer is potassium. High levels of potassium in the blood, known as hyperkalemia, can lead to cardiac arrhythmias by affecting the electrical activity of the heart. This can disrupt the normal rhythm of the heart and lead to serious complications. Chloride, phosphorus, and sodium imbalances are not typically associated with cardiac arrhythmias, making them incorrect choices.

Correct Answer: B

Rationale: Stimulation of the sympathetic nervous system leads to an increase in cardiac output. When the sympathetic nervous system is activated, it causes the heart to beat faster and with more force, leading to an increased cardiac output. Choices A, C, and D are incorrect because the sympathetic nervous system does not cause decreased blood flow to the skeletal muscles, decreased respiratory rate, or increased urinary output.