Integumenatry System. Ch 5. The Skin as an Organ. Function. Protection- mechanical, chemical, bacterial Body temperature regulation Prevent water loss Metabolic- synthesize vitamin D Cutaneous Sensation Blood reservoir Excretion Prevent UV damage. The Skin.
An organ, cells constantly dying and being replaced
Fibroblasts (synthesize collagen, elastin, and reticulin), histiocytes, endothelial cells, perivascular macrophages and dendritic cells, mast cells, smooth muscle, and cells of peripheral nerves and their end-organ receptors.
Collagen & reticulin - provide tensile strength
Elastic fibers- provide for restoration of shape after a deformation
c. Ground substance
glycosaminoglycans: hyaluronic acid, chondroitin sulfate, and dermatan sulfate.
This layer contains adipose tissue and serves to attach the dermis to its underlying tissues.
Some variations in human skin color
(Sub-Saharan African, Indian, Southern European, and Northwest European)
Skin color due to: Melanin, Carotene & Hemoglobin
Human complexions are generally classified into six skin types:
I -light skinned, burns easily, never tans
II - light skinned, burns easily, tans some
III - light skinned, burns occasionally, tans well
IV - light skinned, tans well, rarely burns
V - brown skinned (Asian, Indo-Asian, Chinese, Japanese), tans well, burns rarely, can sunburn after prolonged exposure to UVR
VI - black skinned (Afro-Caribbean), deeply pigmented, can burn after prolonged exposure to UVR
25% US pop
Normal mole Melanoma
Hair bulb in follicle
1st Degree: epidermal damage
2nd Degree: epidermis & upper dermis
3rd Degree: entire thickness of skin