Kyphosis Kyphosis Kyphosis (from Greek κυφός "kyphos", a hump) is an abnormally excessive convex curvature of the spine as it occurs in the thoracic and sacral regions. (Abnormal inward concave "lordotic" curving of the cervical and lumbar regions of the spine is called lordosis.) Kyphosis can be called roundback or Kelso's hunchback. It can result from degenerative diseases such as arthritis; developmental problems, most commonly Scheuermann's disease; osteoporosis with compression fractures of the vertebra; multiple myeloma or trauma. A normal thoracic spine extends from the 1st to the 12th vertebra and should have a slight kyphotic angle, ranging from 20° to
Albinism in humans all vertebrates, including humans. It is due to absence or defect of tyrosinase, a copper-containing enzyme involved in the production of melanin. It is the opposite of melanism. Unlike humans, other animals have multiple pigments and for these, albinism is considered to be a hereditary condition characterised by the absence of melanin in particular, in the eyes, skin, hair, scales, feathers or cuticle. While an organism with complete absence of melanin is called an albino, an organism with only a diminished amount of melanin is described as leucistic or albinoid. The term is from the Latin "albus", "white". There are