What structures are used to sense touch?

Touch is sensed by specialized structures in the skin called mechanoreceptors. These receptors convert mechanical stimuli, such as pressure, vibration, and stretching, into electrical signals that are transmitted to the brain. There are several types of mechanoreceptors, each sensitive to a specific type of touch sensation.

1. Meissner's corpuscles: These are located in the dermal papillae, which are small projections on the surface of the skin. Meissner's corpuscles are responsible for sensing fine touch and texture.

2. Merkel's discs: These are located in the epidermis, the outermost layer of the skin. Merkel's discs are involved in sensing fine touch, pressure, and vibration.

3. Ruffini endings: These are located in the dermis, the layer of skin below the epidermis. Ruffini endings are sensitive to skin stretch and pressure.

4. Free nerve endings: These are unspecialized nerve endings that are found throughout the skin. Free nerve endings are involved in sensing pain, temperature, and itching.

Each of these mechanoreceptors has a unique structure and function that allows it to detect different types of touch sensations. The brain integrates the signals from these receptors to create a comprehensive perception of touch.