Bulbous corpuscle

Sensory receptor in the skin

Ruffini corpuscle by Angelo Ruffini

The bulbous corpuscle, also known as the Ruffini ending, is a type of sensory receptor found in the skin and other tissues. It is primarily responsible for detecting sustained pressure and skin stretch, contributing to the sensation of proprioception and kinesthesia.

Structure

The bulbous corpuscle is a spindle-shaped receptor located in the deeper layers of the skin, such as the dermis and subcutaneous tissue. It consists of a network of nerve endings intertwined with collagen fibers, which are encapsulated in a fluid-filled capsule. This structure allows the corpuscle to respond to mechanical deformation of the skin.

Diagram of Ruffini corpuscle in the skin

Function

Bulbous corpuscles are classified as mechanoreceptors, which are sensitive to mechanical changes in the environment. They are particularly responsive to sustained pressure and skin stretch, making them essential for detecting grip and finger position. This function is crucial for tasks that require fine motor skills and manipulation of objects.

Location

These receptors are distributed throughout the body, with a higher concentration in areas such as the fingertips, soles of the feet, and the oral mucosa. They are also found in the joint capsules, where they contribute to the sense of joint position and movement.

Role in Proprioception

Proprioception is the body's ability to perceive its own position in space. Bulbous corpuscles play a significant role in this process by providing feedback on the position and movement of the skin and joints. This information is integrated with input from other sensory receptors to maintain balance and coordination.

Gray's Anatomy illustration of Ruffini corpuscle

Clinical Significance

Damage or dysfunction of bulbous corpuscles can lead to impaired proprioception and difficulties with tasks that require precise movements. Conditions such as peripheral neuropathy can affect these receptors, leading to a loss of sensation and coordination.

History

The bulbous corpuscle was first described by the Italian anatomist Angelo Ruffini in the early 20th century. His work laid the foundation for understanding the role of these receptors in the sensory system.

Related pages

• Mechanoreceptor
• Proprioception
• Sensory system
• Peripheral neuropathy