The skin that covers the top and back of the head and is usually covered with hair, is termed the scalp.
The scalp is the same as the skin on other parts of the body except, it is some of the thickest skin of the body and it carries more blood than the rest of the skin. This is why deep lacerations to the scalp tend to bleed profusely.
The scalp consists of five layers with the first three tightly bound together and moving as a unit. The outer layer contains approximately 100,000 hair follicles. Each hair follicle contains the root of a hair shaft that produces the head's covering of hair. The growth and density of the hair is influenced by genes, nutrition, and hormones.
Many skin conditions that affect the scalp can go unnoticed because of all the hair, so it's important to check the scalp carefully for moles and other growths that could be dangerous if left untreated.
The scalp also contains sweat glands and many sebaceous glands. The sebaceous glands produce oil or sebum that protects the hair.
One of the more notorious practices of human beings has been the scalping of one human by another human. Scalping is the act of cutting or tearing a part of the human scalp, with hair attached, from the head. This practice has been a part of conflicts with the scalp being a war trophy, a warning to others, or as proof of a killing for bounty money.
Scalping was first recorded by the Greek historian Herodotus writing in the 5th century BC. He wrote about Scythian soldiers from the Black Sea area of Europe who scalped their dead enemies. The practice was brought to America by the British and French, and has long been a sensitive topic in the history of this country.
The Dutch governor of Manhattan (now part of New York City) offered the first bounty in North America for Indian scalps in 1641. During the territorial conflicts of the early 1700s, in what is now the USA and Canada, the French were paying for British scalps, the British were paying for French scalps, and each was paying for the scalps of the other's Indian allies.
Larrie Stone is a retired Dana College science professor.