ridge

alveolar ridge a bony ridge of the maxilla or mandible, the part of the alveolar process that contains the alveoli; called also alveolar crest.

dental ridge any linear elevation on the crown of a tooth.

dermal r's ridges of the skin produced by the projecting papillae of the corium on the palm of the hand and sole of the foot, producing a fingerprint and footprint characteristic of the individual; called also cristae cutis.

genital ridge the more medial part of the urogenital ridge, giving rise to the gonad.

healing ridge an indurated ridge that normally forms deep to the skin along the length of a healing wound.

incisal ridge the part of the crown of an anterior tooth that makes up the actual incisal portion; see incisal surface, under surface.

interureteric ridge a fold on mucous membrane extending across the bladder between the ureteric orifices.

mammary ridge an ectodermal thickening in early embryos, along which the mammary glands subsequently develop.

mesonephric ridge the more lateral portion of the urogenital ridge, giving rise to the mesonephros.

oblique ridge a variable linear elevation obliquely crossing the occlusive surface of a maxillary molar.

urogenital ridge a longitudinal ridge in the embryo, lateral to the mesentery.

A. Vertical ridges that appear on the nail can indicate disorders as simple as iron deficiency, poor absorption of vitamins and nutrients, overall poor health or they could indicate something as serious as kidney trouble.
it might be wise to get a blood test.