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.