Shark skeletons are made of flexible cartilage for agility. Skin covered with dermal denticles reducing surface drag. Sharks shed denticles as they grow, some as defensive spines
Outermost layer of epidermis containing dead tissue. Composed of 15-20 layers of flattened cells without nuclei. Thickness ranges from 10 to 40 μm. Contains keratin protein network for hydration
Suede is a fuzzy, napped leather made from animal skin undersides. Term comes from French "gants de Suède" meaning Swedish gloves. Primarily made from lamb, but also goat, calf, and deer
Integumentary system forms outer layer of animal's body. Includes skin, hair, scales, feathers, hooves, claws, and nails. Human skin covers 1.5-2 m2 surface area, 12-15% body weight
Sebaceous glands are microscopic exocrine glands in skin that secrete sebum. Found throughout skin except palms and soles. Most numerous on face and scalp, also present in eyelids and nipples. Two types: connected to hair follicles and independent
Skin is largest organ, covering 15% of adult body weight. Organized into epidermis, dermis and hypodermis layers. Epidermis is 90-95% keratinocytes, 5-10% non-keratinocytes