Skin Cell Types

Keratinocytes Keratin producing cells Make up 90% of all epidermal cells

Melanocytes Epidermal cells (~8%) which produce melanin

Langerhans cells Participate in immune responses against microbes invading the skin

Merkel cells Least numerous epidermal cells, found in deepest layer Function in sensation of touch

Meissner corpuscles Receptors for fine touch located in dermal papillae of hairless skin

Thermoreceptors Detect changes in temperature

Mechanoreceptors Detect pressure, stretching, touch

Nociceptors Detect pain, usually as a result of physical or chemical damage to skin

Pacinian corpuscles Detect pressure

Fibroblasts Immature cells that secrete fibers and the matrix in loose and dense connective tissue

Macrophages Cells that remove foreign particles by engulfing them

Mast cells Cells that secrete histamine which dilates blood vessels during inflammation

Adipocyte Fat cell Stores fat to be used for energy/insulation

Functions of the Skin Function Regulations of body temperature Cells/structures maintaining homeostasis Regulations of body temperature High body temp – sweat  evaporates to cool Changes in blood flow regulate as well Sweat glands Blood vessels

Function of the Skin Function Protection Stratified squamous cells Cells/Structures maintaining homeostasis Protection From abrasion From bacterial invasion From dehydration From UV radiation Stratified squamous cells Macrophages Keratinocytes Langerhans cells

Function of the Skin Function Sensation Mechanoreceptors Nociceptors Cells/Structures maintaining homeostasis Sensation Detect stimuli Mechanoreceptors Nociceptors Merkel cells Meissner corpuscles Thermoreceptors Pacinian corpuscles

Function of the Skin Function Excretion Sweat glands Cells/Structures maintaining homeostasis Excretion Small amounts of water, salts, etc Sweat glands

Function of the Skin Function Immunity Macrophages Langerhans cells Cells/Structures maintaining homeostasis Immunity Fight foreign invaders of the body Macrophages Langerhans cells

Function of the Skin Function Synthesis of vitamin D melanocytes Cells/Structures maintaining homeostasis Synthesis of vitamin D Sun exposure initiates synthesis of vitamin D melanocytes