Lanugo hair
As lanugo , lanugo (v. Lat. : Lana " wool "), or woolly refers to the downy hair, of the fetus covered.
The lanugo is a protection for the skin of the unborn child and is created around the 13th to 16th week of pregnancy . Every hair has a sebum gland that produces a fatty substance called vernix caseosa ( cheese smear ). The lanugo hair helps the cheese smear stick to the body. This protects the skin from being softened by the amniotic fluid . With the development of the cheese smear, the lanugo hair is an important part of the skin of the fetus and serves to protect it from vibrations, sound and pressure .
Lanugo hair is shed towards the end of pregnancy, which means that a large part of the vernix is also lost. In the places where larger areas of hair remain (head, eyebrows, eyelashes, shoulder girdle, sacrum area), cheese smear remains. In some infants , the lanugo is still present after birth, but fails shortly afterwards.
It is believed that the fetus reabsorbs part of the shed lanugo hair through the mouth, whereupon the keratins contained in it stimulate the peristalsis of the child's intestine.
Just like the cheese smear, the lanugo hair counts as a criterion for assessing the degree of maturity of the newborn. The less that is left at birth, the more mature the child is assessed.
Lanugo hairs can develop in people with malignant tumors or extremely low body weight (e.g. anorexia ). Lanugo hair is therefore also a protective mechanism for the body against heat and cold when this function can no longer be guaranteed due to the dwindling fatty tissue. In addition, prolonged application of Minoxidil and the consumption of diazoxide , phenytoin and ciclosporin can trigger renewed growth of lanugo hair.
In evolutionary terms , this can be explained in humans as a genetic remnant ( rudiment ) of their ape-like ancestors. Monkey fetuses also develop a lanugo, which is only replaced by a fur at a later point in time .
See also
literature
- Christine Mändle, Sonja Opitz-Kreuter, Andrea Wehling: The midwife book: textbook of practical obstetrics. 2nd Edition. Schattauer, Stuttgart / New York 1997, ISBN 3-7945-1765-2 .