___are receptors that detect internal stretching.Group of answer choicesPacinian corpuscleMerkel's discRuffini's corpuscleHair root plexus

The receptors that detect internal stretching are known as Ruffini's corpuscles. These mechanoreceptors are found in the skin and various connective tissues, and they respond to sustained pressure and skin stretch, which helps the body perceive changes in body position and movement. In contrast, Pacinian corpuscles are sensitive to deep pressure and vibration, Merkel's discs are involved in detecting light touch, and hair root plexuses are associated with the sensation of movement in hair follicles.

In summary, if you're looking for receptors that specifically detect internal stretching, the answer is Ruffini's corpuscles.