PSL300H1 Chapter 11: Chapter 11 Somatosensory Receptors
Document Summary
Groups a - are large diameter, myelinated afferents, and are relatively specialized. Afferent coupled to the base of a hair follicle produces a receptor potential whenever hair is bent. A and c have small diameter axons, many are less specific and excitable by different modalities such as temperature, pressure, chemical agents. Some a have expanded tips ruffini endings and function as mechanoreceptors some c fibers function solely as mechanoreceptors. Most small axons are activated by stimuli of sufficient intensity as to be harmful and which are perceived as painful. Thermoreceptors are a third group of small afferents. Rapidly adapting receptor, responding only to changes in pressure. The receptive field of a neuron is the surface area from which a response can be elicited by application of an adequate stimulus. Thermo and chemoreceptors are generally slowly adapting, small afferents in the group a -c range. Their responses may contain rapidly adapting, dynamic components.
