Scalp

scalp the integument covering the top of the head. It consists of three layers of tissue: the skin, an underlying layer of tissue and blood vessels, and the occipitofrontalis muscle stretching from the eyebrows to the back of the head. Except for its abundant growth of hair, the skin of the scalp resembles that of the rest of the body but is especially rich in blood vessels. Hence profuse bleeding may be associated with scalp injuries.

Baldness

Baldness is the partial or complete lack of hair, and part of the wider topic of "hair thinning". The degree and pattern of baldness varies, but its most common cause is androgenic alopecia, alopecia androgenetica, or alopecia seborrheica.
Pattern balding is distinct from alopecia areata, which commonly involves patchy hair loss. Extreme forms of alopecia areata are alopecia totalis, which involves the loss of all head hair, and the most extreme form, alopecia universalis, which involves the loss of all hair from the head and the body.