Final answer:
Ruffini corpuscles, also known as bulbous corpuscles, are specialized mechanoreceptors that detect heavy touch, stretch in the skin, and joint movements, contributing to proprioception and kinesthesia.
Step-by-step explanation:
The corpuscles that consist of flattened elongated capsules specialized for detecting heavy touch, stretching of the skin, and joint movement are known as Ruffini corpuscles, or bulbous corpuscles. These mechanoreceptors are encapsulated, slow-adapting, and are found both in glabrous and hairy skin. Positioned deeper within the epidermis, near the base, Ruffini corpuscles play a crucial role in the body by detecting skin stretch, joint deformations, and warmth, which is essential for proprioception and kinesthesia, helping with the control of object gripping and finger movement.