Largest single organ of the body.
Skin
Typically accounting for 15% to 20% of total body weight and, in adults, presenting 1.5 to 2m 2 of surface to the external environment.
Skin
The skin in composed of: [2]
an epithelial layer of ectodermal origin.
[epi/dermis]
Epidermis
a layer of mesodermal connective tissue.
[epi/dermis]
Dermis
A stratified squamous keratinized epithelium composed of cells.
Keratinocytes
[5] Functions of skin
2 types of skin
Covers the palms and soles.
[types of skin]
Thick skin
400 to 1400 μm (1.4 mm).
[types of skin]
Thick skin
Covers the whole body except the palms and the soles.
[types of skin]
Think skin
Varies from 75 to 150 μm.
[types of skin]
Thin skin
[5] Layers of Epidermis
[2] Layers of Dermis
[3] Types of hair
Deepest, single layer of cuboidal to low columnar cells in contact with basement membrane.
[layers of epidermis]
Stratum basale
Mitosis occurs here.
[layers of epidermis]
Stratum basale
Melanocytes and Merkel cells also present.
[layers of epidermis]
Stratum basale
Thickest layer.
[layers of epidermis]
Stratum spinosum
Consists of polyhedral cells with histologic appearance of many short “spines” or prickles at the cell surface.
[layers of epidermis]
Stratum spinosum
Several layers of keratinocytes all joined by desmosomes; Langerhans cells also present.
[layers of epidermis]
Stratum spinosum
3-5 layers of keratinocytes with distinct keratohyaline granules.
[layers of epidermis]
Stratum ganulosum
2-3 layers of anucleate, dead cells; seen only in thick skin.
[layers of epidermis]
Stratum lucidum
Most superficial layer .
[layers of epidermis]
Stratum corneum