Should neurons in the skin be part of skin adnexa

[sbello]

Question from Melissa
"Skin MP terms don’t mention nerves. Are skin sensory neurons part of the skin adnexa?"

In Uberon there are no neuron/nerve terms under integumentary adnexa bot most of the sensory neuron terms in Uberon are imported from CL.

The text definitions of integumentary adnexa (http://purl.obolibrary.org/obo/UBERON_0006003) is "Anatomical structure embedded in or located in the integument that is part of the integumental system. Examples: hair, follicles, skin glands, claws, nails, feathers". Based on the text definition it seems like sensory neurons in the skin would be part of the adnexa but I need to dig around some more.

[sbello]

MP has terms abnormal cutaneous/subcutaneous mechanoreceptor morphology (MP:0000973) these are only found under nervous system.
Other terms like abnormal olfactory sensory neuron morphology are in both the nervous system and the tissue (abnormal olfactory epithelium morphology) in which they are located

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7827880/

The entire nerve probably should not be under skin adnexa as parts of the nerve are not in the adnexa but it seems like the mechanoreceptors maybe should be.

https://www.sciencedirect.com/science/article/pii/B9780128029008000245
Adnexa

Adnexa is a term used to include (1) pilosebaceous units, (2) modified sebaceous glands, (3) eccrine and apocrine sweat glands, and (4) nails. Each of these are integrated into the skin as a whole, but are usually considered as independent organs because their anatomy, development, and molecular regulation is highly specialized and relatively independent of the epidermis and dermis.

The skin consists of a series of distinct tissue types: (1) epidermis (epithelial cells), (2) dermis (collagen, fibroblasts, mast cells, nerves, blood vessels), (3) hypodermis (white adipose tissue), (4) panniculus carnosus muscle (in rodents), and (5) adventitia (subcutaneous tissue). Each is a complex structure in and of itself, as described and illustrated below.

Based on this we should include the mechanoreceptors in the appropriate skin layer but not as part of the adnexa