The hypodermis is the innermost and thickest layer of the skin. It invaginates into the dermis and is attached to the latter, immediately above it, by collagen and elastin fibres. It is essentially composed of a type of cells specialised in accumulating and storing fats, known as adipocytes.
Fatal familial insomnia Fatal familial insomnia (FFI) is a very rare, autosomal dominant inherited, disease of the brain. It is caused by a mutation in a protein called prion protein (PrP): asparagine-178 is replaced by aspartic acid.
Insomnia (say: in-sohm-nee-uh) is a sleep disorder. People who have insomnia may not be able to fall asleep. They may wake up during the night and not be able to fall back asleep, or they may wake up too early in the morning. Many people have insomnia. Chronic insomnia is when your sleeping problem lasts for 4 weeks or longer.