What do sensory nerve endings register?

The sensory nerve endings are specialized neurones that are stimulated to fire action potntiels based on chemical factors, photons, heat etc depending on their location and type.

afferent nerve endings?

Free nerve endings functions as cutaneous receptors ( is a sensory receptor present on dermis or epidermis ). Present in vertebrates for sense of pain. they are frequently found on skin.

Are light touch receptors that detect bending of hairs. Eg: The tickle of a mosquito landing on your skin is mediated by hair follicle receptors.

dermis(cutis vera)