Which sensory receptors sense pressure and vibration changes deep in the skin?

Pacinian corpuscles, also known as Lamellar corpuscles, are specialized sensory receptors located deep within the dermis and subcutaneous tissue of the skin. These receptors are highly sensitive to pressure and vibrations. Structurally, they are composed of concentric layers of connective tissue that create a unique arrangement enabling them to respond to rapid changes in pressure and high-frequency vibrations.

The function of Pacinian corpuscles is crucial for perceiving deep pressure sensations, which are important for activities like feeling the texture of objects and detecting vibrations through surfaces. When pressure is applied, the layers compress, which triggers an electrical impulse in the nerve fibers, allowing the sensation to be relayed to the brain.

In contrast, Meissner's corpuscles are more sensitive to light touch and are located closer to the surface of the skin. Merkel cells are involved in sensing light touch and the shape and texture of objects, while free nerve endings are responsible for detecting pain and temperature rather than pressure and vibration.

Therefore, Pacinian corpuscles are the correct answer because of their specific role and location in sensing deeper pressure and vibration changes within the skin.