The integumentby Syafiqa Al-Azua Binti Aljeffry
I’d like to talk about • How many layers are there in the
skin ?• What are these layers made of ?• What are their significant
functions ?
But.
What is this …. SKIN?
1.Largest organ
2.Also known as INTEGUMENT or CUTANEOUS LAYER
Our skin are made of 3 basic layersEpidermis Dermis Hypodermis
Epithermal layer of ectodermal origin
A layer of mesodermal connective tissue
Beneath the dermis
1st skin layer- Epidermis Outermost layer of the skin Have 4 different types of cells But mainly are STRATIFIED SQUAMOUS KERATINIZED
EPITHILIUM – composed of cells called keratinocytes The other NON-KERATINOCYTE CELLS pigment-producing melanocytes antigen-producing langerhans cells tactile merkel cells
Layers of epidermis Stratum corneum Stratum lucidum
Stratum granulosum – the granular layer Stratum spinosum – the spinous layer
Stratum basale – the basal layer
WHAT IT DOES -• Supports epidermis & binds it to the hypodermis• Site for epidermal derivatives (e.g: hair follicles &
glands)
COMPONENTS – • irregular in shape & has many projections called Dermal
Papillae.• Have abundance of nerve supply
Have BASEMENT MEMBRANE• located in between the epidermis’s stratum basale &
dermis’s papillary layer.• Composed of Basal Lamina and Reticular Lamina• Important for nutrients to pass through from the
vascular dermis into the avascular epidermis.
Consists of 2 layers with indistinct boundaries• OUTERMOST PAPILLARY LAYER• Constitutes the major parts of the dermis• Functions : produce anchoring – to be inserted into
basal lamina for the binding of dermis and epidermis • DEEPER RETICULAR LAYER• Thicker & composed of irregular dense CT• Has more fibers than cells• Present of elastic fiber to provide elasticityu
DERMIS
Dermal papillae• Projections of dermal layers into the epidermis.• Interlock with epidermal pegs• It is more numerous in skin that is subjected to frequent
pressure. HOW??? By increasing the epidermal-dermal junction
HypoDermis1. Consists of loose connective tissue – e.g: fat cells /
adipocytes (vary in number according to different region of the body & vary in size according to the nutritional state)
2. Binds the skin loosely to the subjacent organs - This enable the skin to slide over them.
3. Have an extensive vascular supply – promote rapid uptake of insulin / drug injected into the tissue.