Key Points

Separate sensory pathways carry information about each of the special senses of vision, taste, olfaction, and equilibrium and about the general somatosensory sensations of touch, proprioception, pain, and temperature. Somatosensory mechanoreceptors display distinct physiologic properties based on receptive field size, ability to adapt to the stimulus with time, stimulus threshold, and response time. The propagation rate of action potentials varies with the diameter of the nerve fiber and the degree of myelination.

Pacinian corpuscles are rapidly adapting mechanoreceptors that act as rate detectors with large receptive fields. Ruffini's endings are mechanoreceptors with large receptive fields and sustained responses. Meissner's corpuscles and Merkel's disks are mechanoreceptors with small receptive fields. The former is a rapidly adapting cell; the latter is slowly adapting.

Nociceptors contribute to the perception of pain by transmitting information about high intensities of mechanical, thermal, or chemical stimulation.

Nociceptors and central nervous system neurons that comprise central pain pathways may both exhibit hyperalgesia after exposure to a painful stimulus.

Thermoreceptors in the skin are rapidly adapting and have a limited response range. Thermoreceptors within the central nervous system exhibit acute sensitivity and allow the body to maintain the temperature of the nervous system within its narrow functional range.

Proprioceptors in muscles and joints send information about body position and movement to the cerebellum and other motor centers in the brain in order to maintain posture and aid in muscle reflexes.

Visceral sensory fibers provide general information about mechanical, thermal, and chemical stimuli, but the sensation is not well localized and is often referred, or perceived as emanating from some unstimulated part of the body.

Essential Medical Physiology, Third Edition

Psychology Of Weight Loss And Management

Psychology Of Weight Loss And Management

Get All The Support And Guidance You Need To Be A Success At The Psychology Of Weight Loss And Management. This Book Is One Of The Most Valuable Resources In The World When It Comes To Exploring How Your Brain Plays A Role In Weight Loss And Management.

Get My Free Ebook


Post a comment