Each woman filled in a questionnaire about the extent of her hair loss and had her iron level (serum ferritin) tested. Among the women who described their hair loss as excessive, 59% had low iron stores compared to the remainder of the population. Decreased Serum Ferritin is Associated with Alopecia in Women.
The upper shell of the turtle is called the carapace. The lower shell that encases the belly is called the plastron. The carapace and plastron are joined together on the turtle's sides by bony structures called bridges. The inner layer of a turtle's shell is made up of about 60 bones. It include parts of the backbone and the ribs, meaning the turtle cannot crawl out of its shell.
The shell itself is made of bone, and the outer covering of the shell is made of keratin, much like human fingernails. Each shell is made up of sections called scutes. As the turtle grows, new layers of keratin are formed around the outer edges of each scute, looking much like the growth rings of a tree.