Where are Ruffini corpuscles primarily located?

Ruffini corpuscles, also known as Ruffini endings, are mechanoreceptors that play a crucial role in detecting skin stretch and sustained pressure. They are primarily located in the deep layers of the dermis, specifically within the superficial dermis of both hairy and glabrous (non-hairy) skin. This location allows them to effectively sense the stretching of the skin, which is important for proprioception and the perception of joint position. Being situated in the superficial dermis means they are accessible to the mechanical changes in the skin and can respond to prolonged pressure, providing the body with important sensory feedback.

While Ruffini corpuscles can also be found in other areas, such as joint capsules and some deeper structures, their primary presence in the superficial dermis of both types of skin is what differentiates them from other sensory receptors and is essential for their function in mechanotransduction.