Lanugo

As lanugo, lanugo ( from Latin: lana " wool" ) or woolly refers to the downy hair that covers the fetus.

The lanugo is a protection for the skin of the unborn and produced approximately in the 13th to 16th week of pregnancy. Each hair is one of a sebaceous gland that produces an oily substance, the vernix caseosa ( vernix ). The lanugo contributes to the vernix remains attached to the body. Thus, the skin is protected from the softening through the amniotic fluid. With the development of vernix the lanugo is an important part of the skin of the fetus and serves to protect it from vibration, noise and pressure.

The lanugo is shed at the end of pregnancy, which is also a large part of the vernix is lost. At the places where to get bigger hair areas remain (head, eyebrows, eyelashes, shoulder girdle, sacrum area) is preserved vernix. In some infants, the lanugo is still present even after birth, but falls short of it.

It is believed that the fetus receives back a portion of the lanugo repelled by mouth, whereupon the keratins contained therein stimulate the peristalsis of the child's intestine.

Just as the vernix counts the lanugo as a criterion for assessing the maturity of newborn infants. The less at birth is still present, the more mature the child is assessed.

In people with malignant tumors as well as extremely low body weight (eg, anorexia ) can cause the formation of a lanugo. Also, can trigger renewed growth of lanugo hairs longer applying minoxidil and taking diazoxide, phenytoin and cyclosporine.

The theory of evolution suggests the lanugo in humans as a genetic remnant ( rudiment ) his ape-like ancestors. Monkey fetuses also form a lanugo, which will be replaced at a later time by a coat.