integumentary system Flashcards
integumentary system
organ system consisting of hair, skin, nails, and exocrine glands.
function
act as a barrier to protect body from outside world.
skin
used to protect the body from chemicals, UV rays, disease, and physical damage
hair and nails
extend from the skin to help protect it from environmental damage.
exocrine glands
produce sweat, oil, and wax, to cool, protect, and moisturize the skins surface.
epidermis
most superficial layer of skin that covers almost the entire body. receive all nutrients from dermis.
epidermis cells
keratinocytes: develop from stem cells and begin to produce the protein keratin
keratin
makes the keratinocytes tough, scaly, and water resistant.
dermis
deep layer of skin found under epidermis. gives skin strength and elasticity. made of dense irregular connective tissue, blood vessels, blood, and nervous tissue.
2 regions
papillary layer and reticular layer
papillary layer
contains many finger-like extensions called dermal papillae that protrude superficially towards the epidermis
reticular layer
made of dense irregular connective tissue that contains many tough collagen and stretchy elastin fibers running in all directions to provide strength and elasticity to the skin
hypodermis
Deep to the dermis is a layer of loose connective tissues known as the hypodermis, subcutis, or subcutaneous tissue. serves as the flexible connection between the skin and the underlying muscles and bones as well as a fat storage area
hair
The few hairless parts of the body include the palmar surface of the hands, plantar surface of the feet, lips, labia minora, and glans penis.helps to protect the body from UV radiation by preventing sunlight from striking the skin. Hair also insulates the body by trapping warm air around the skin
3 distinct layers of hair cells
cuticle, cortex, and medulla
cuticle
outermost layer made of keratinocytes.
cortex
form the majority of the hairs width
medulla
not present in all hair cells. when present hair contains highly pigmented cells full of keratin, when absent, cortex runs through rest of hair.
Sudoriferous Glands
exocrine glands found in the dermis of the skin and commonly known as sweat glands
2 types
eccrine sweat glands and apocrine sweat glands
eccrine sweat glands
found in almost every region of the skin and produce a secretion of water and sodium chloride, delivered via a duct to the surface of the skin and is used to lower the body’s temperature through evaporative cooling
apocrine sweat glands
found in mainly in the axillary and pubic regions of the body, Apocrine sweat glands are inactive until puberty, at which point they produce a thick, oily liquid that is consumed by bacteria living on the skin. The digestion of apocrine sweat by bacteria produces body odor
Sebaceous Glands
exocrine glands found in the dermis of the skin that produce an oily secretion known as sebum. found in every party of the body except thick skin of the hands and feet.
sebum
acts to waterproof and increase elasticity of skin. lubricates and protects cuticles of hair
Ceruminous Glands
found only in the dermis of the ear canals. Ceruminous glands produce a waxy secretion known as cerumen to protect the ear canals and lubricate the eardrum.
thermoregulation
when the body becomes too warm, sweat is produced by sebaceous glands. The evaporation of water on the skin creates a cooling effect on the skin. Blood vessels can also dilate when the body is warm. If the body is too cold, blood vessels constrict so that less blood is carried to the skin surface.
