You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Which of the following are the slowly adapting mechan- oreceptors present in the skin that are very sensitive to perpendicular indentation? and explain in detail?
Ans. c (Merkel discs). (Ref. Ganong Physiology 21st ed., 125)MECHANORECEPTORS# Four types of mechanoreceptors in glabrous skin are-two in the superficial layers (Meissner's corpuscles and Merkel discs) and two in the subcutaneous tissue (Ruffini endings and Pacinian corpuscles).Meissner's corpuscles# are rapidly adapting mechanoreceptors# respond to Low frequency vibrations, stroking and fluttering types of tactile stimuli.Merkel disc receptors# are slowly adapting receptors# respond to pressure and texture.Pacinian corpuscles# are rapidly adapting and# respond to high frequency vibrations.Ruffini endings# are slowly adapting receptors that respond to skin stretch.# These endings link subcutaneous tissue to skin folds overlying joints.The afferent fibres of these receptors are myelinated and include:# large (group A alpha),# medium (group Ab),# small (group Adelta) diameter fibres.# Smallest (group A gama)- Tactile sensitivity is greatest on the glabrous (hairless) skin of the hands, the soles of the feet, and the lips.