A nail is a horn-like envelope covering the tips of the fingers and toes in most primates and a few other mammals. Nails are similar to claws in other animals. Fingernails and toenails are made of a tough protective protein called alpha-keratin. This protein is also found in the hooves and horns of different animals.
A comedo is a clogged hair follicle (pore) in the skin.[2] Keratin (skin debris) combines with oil to block the follicle.[3] A comedo can be open (blackhead) or closed by skin (whitehead), and occur with or without acne.[3] The word comedo comes from the Latin comedere, meaning “to eat up”, and was historically used to describe parasitic worms; in modern medical terminology, it is used to suggest the worm-like appearance of the expressed material.[1]
Tephra is fragmental material produced by a volcanic eruption regardless of composition, fragment size or emplacement mechanism.[1]
Volcanologists also refer to airborne fragments as pyroclasts. Once clasts have fallen to the ground they remain as tephra unless hot enough to fuse together into pyroclastic rock or tuff.
Tephra is fragmental material produced by a volcanic eruption regardless of composition, fragment size or emplacement mechanism.[1]
Volcanologists also refer to airborne fragments as pyroclasts. Once clasts have fallen to the ground they remain as tephra unless hot enough to fuse together into pyroclastic rock or tuff.
Tephra is fragmental material produced by a volcanic eruption regardless of composition, fragment size or emplacement mechanism.[1]
Volcanologists also refer to airborne fragments as pyroclasts. Once clasts have fallen to the ground they remain as tephra unless hot enough to fuse together into pyroclastic rock or tuff.
Tephra is fragmental material produced by a volcanic eruption regardless of composition, fragment size or emplacement mechanism.[1]
Volcanologists also refer to airborne fragments as pyroclasts. Once clasts have fallen to the ground they remain as tephra unless hot enough to fuse together into pyroclastic rock or tuff.
Tephra is fragmental material produced by a volcanic eruption regardless of composition, fragment size or emplacement mechanism.[1]
Volcanologists also refer to airborne fragments as pyroclasts. Once clasts have fallen to the ground they remain as tephra unless hot enough to fuse together into pyroclastic rock or tuff.
