THE INTEGUMENTARY
SYSTEM
,• The integumentary system refers to the skin and its accessory structures.
• In the adult human body, the skin makes up about 16% of body weight and co
area of 1.5 to 2 m2.
• The skin and accessory structures are the largest organ system in the human
• Consequently the skin protects your inner organs and it is in need of daily car
protection to maintain its health.
• The skin is made of multiple layers of cells and tissues, which are held to und
structures by connective tissue.
• The deeper layer of skin is well vascularized, and also has numerous sensory,
sympathetic, and autonomic nerve fibers.
• The skin is composed of two main layers:
• The epidermis, made of closely packed epithelial cells, and
• The dermis, made of dense, irregular connective tissue that houses blood vessels, hair
sweat glands, and other structures.
• Beneath the dermis lies the hypodermis, which is composed mainly of loose
connective and fatty tissues.
,THE INTEGUMENTARY SYSTEM
, • The epidermis is the most superficial layer of the skin and is composed
stratified keratinised squamous epithelium.
• It is made of four or five layers of epithelial cells, depending on its locat
the body, and is avascular.
• Skin that has four layers of cells is referred to as “thin skin.”
• From deep to superficial, these layers are the stratum basale1, stratum
spinosum2, stratum granulosum3, and stratum corneum4.
• “Thick skin” is found only on the palms of the hands and the soles of th
• It has a fifth layer, called the stratum lucidum*, located between the str
corneum and the stratum granulosum.
• The cells in all of the layers except the stratum basale are called keratin
• A keratinocyte is a cell that manufactures and stores keratin, an intrace
fibrous protein that gives hair, nails, and skin their hardness and water-
resistant properties.
SYSTEM
,• The integumentary system refers to the skin and its accessory structures.
• In the adult human body, the skin makes up about 16% of body weight and co
area of 1.5 to 2 m2.
• The skin and accessory structures are the largest organ system in the human
• Consequently the skin protects your inner organs and it is in need of daily car
protection to maintain its health.
• The skin is made of multiple layers of cells and tissues, which are held to und
structures by connective tissue.
• The deeper layer of skin is well vascularized, and also has numerous sensory,
sympathetic, and autonomic nerve fibers.
• The skin is composed of two main layers:
• The epidermis, made of closely packed epithelial cells, and
• The dermis, made of dense, irregular connective tissue that houses blood vessels, hair
sweat glands, and other structures.
• Beneath the dermis lies the hypodermis, which is composed mainly of loose
connective and fatty tissues.
,THE INTEGUMENTARY SYSTEM
, • The epidermis is the most superficial layer of the skin and is composed
stratified keratinised squamous epithelium.
• It is made of four or five layers of epithelial cells, depending on its locat
the body, and is avascular.
• Skin that has four layers of cells is referred to as “thin skin.”
• From deep to superficial, these layers are the stratum basale1, stratum
spinosum2, stratum granulosum3, and stratum corneum4.
• “Thick skin” is found only on the palms of the hands and the soles of th
• It has a fifth layer, called the stratum lucidum*, located between the str
corneum and the stratum granulosum.
• The cells in all of the layers except the stratum basale are called keratin
• A keratinocyte is a cell that manufactures and stores keratin, an intrace
fibrous protein that gives hair, nails, and skin their hardness and water-
resistant properties.
