Melanocytes – produce melanin; irregularly shaped
INTEGUMENTARY cells; s. basale
SYSTEM Melanosomes – vesicles derived from GA where
melanin is produced
§ It consists of the skin, and accessory structures
such as hair, glands, and nails.
Factors of Melanin Production
Functions of the Integumentary S. (PSVTE) a. Genetic factors
1. Protection b. Exposure to UV light
2. Sensation c. Hormones
3. Vitamin D production
4. Temperature regulation Albinism - recessive genetic trait that causes deficiency
5. Excretion / absence of melanin
Skin Cyanosis - bluish skin color; decreased blood O2
Epidermis
Carotene – yellow pigment in plants (squash, carrots);
§ Most superficial layer
source of vitamin A
§ Stratified squamous epithelium
§ In deepest layers, mitosis occurs Birthmarks – congenital disorder of the capillaries in the
dermis
Keratinization – cells change shape and chemical
composition; cells become filed with the protein keratin Subcutaneous Tissue
(hard) § Attaches the skin to underlying bones
– transformation of the living cells
§ Also called the hypodermis
of the stratum basale into the dead squamous cells of the
stratum corneum § Loose connective tissue
§ Storage of our body’s fat (padding, insulation)
Stratum basale – deepest; cuboidal & columnar cells,
undergo mitosis every 19 days Accessory Skin Structure
Hair
Stratum corneum – most superficial stratum; dead § Columns of dead, keratinized epithelial cells
squamous cells filled with keratin (structural strength); § Produced in the hair bulb
lipids (prevent fluid loss); joined by desmosomes
Hair follicle – where each hair rises
Callus – thickened area Shaft – above the skin
Root – below the skin
Corn – bony prominence, thickened corn shaped Hair bulb – site of hair cell formation
structure Cortex – hard keratin
Medulla – soft central core
Dermis Cuticle – single layer of overlapping cells that holds the
§ Dense collagenous connective tissue, contains hair in the hair follicle
fibroblasts, adipocytes, macrophages
§ Nerves, hair follicles, smooth muscles, glands, Growth Stage
lymphatic vessels § Hair is formed by epithelial cells within the hair
bulb
Collagen (resist stretching) & elastic fibers – structural § Divide and undergo keratinization
strength § Hair root + shaft = columns of dead keratinized
epithelial cells
Cleavage lines/Tension lines – collagen fibers are
oriented in some directions; skin is most resistant to Resting Stage
stretch along these lines § Growth stops
§ Hair is held in the hair follicle
Stretch marks – skin is overstretched, leaving lines that
are visible Next growth stage
§ A new hair is formed
Dermal papillae – contain blood vessels that supply the § The old hair falls out
epidermis with nutrients, remove waste products, and
regulate body temperature Eyelashes – grow for about 30 days; rest for 105 days
Skin Color Scalp hairs – grow for 3 years; rest for 1 – 2 years
Melanin – pigments responsible for skin, hair, eye color
Arrector Pili – smooth muscles; contraction = hair to
Melanin pigments – yellow (Caucasian), brown stand on end; produces goose bumps
(Asians), black (African)
M o r a n o , M . A .
INTEGUMENTARY cells; s. basale
SYSTEM Melanosomes – vesicles derived from GA where
melanin is produced
§ It consists of the skin, and accessory structures
such as hair, glands, and nails.
Factors of Melanin Production
Functions of the Integumentary S. (PSVTE) a. Genetic factors
1. Protection b. Exposure to UV light
2. Sensation c. Hormones
3. Vitamin D production
4. Temperature regulation Albinism - recessive genetic trait that causes deficiency
5. Excretion / absence of melanin
Skin Cyanosis - bluish skin color; decreased blood O2
Epidermis
Carotene – yellow pigment in plants (squash, carrots);
§ Most superficial layer
source of vitamin A
§ Stratified squamous epithelium
§ In deepest layers, mitosis occurs Birthmarks – congenital disorder of the capillaries in the
dermis
Keratinization – cells change shape and chemical
composition; cells become filed with the protein keratin Subcutaneous Tissue
(hard) § Attaches the skin to underlying bones
– transformation of the living cells
§ Also called the hypodermis
of the stratum basale into the dead squamous cells of the
stratum corneum § Loose connective tissue
§ Storage of our body’s fat (padding, insulation)
Stratum basale – deepest; cuboidal & columnar cells,
undergo mitosis every 19 days Accessory Skin Structure
Hair
Stratum corneum – most superficial stratum; dead § Columns of dead, keratinized epithelial cells
squamous cells filled with keratin (structural strength); § Produced in the hair bulb
lipids (prevent fluid loss); joined by desmosomes
Hair follicle – where each hair rises
Callus – thickened area Shaft – above the skin
Root – below the skin
Corn – bony prominence, thickened corn shaped Hair bulb – site of hair cell formation
structure Cortex – hard keratin
Medulla – soft central core
Dermis Cuticle – single layer of overlapping cells that holds the
§ Dense collagenous connective tissue, contains hair in the hair follicle
fibroblasts, adipocytes, macrophages
§ Nerves, hair follicles, smooth muscles, glands, Growth Stage
lymphatic vessels § Hair is formed by epithelial cells within the hair
bulb
Collagen (resist stretching) & elastic fibers – structural § Divide and undergo keratinization
strength § Hair root + shaft = columns of dead keratinized
epithelial cells
Cleavage lines/Tension lines – collagen fibers are
oriented in some directions; skin is most resistant to Resting Stage
stretch along these lines § Growth stops
§ Hair is held in the hair follicle
Stretch marks – skin is overstretched, leaving lines that
are visible Next growth stage
§ A new hair is formed
Dermal papillae – contain blood vessels that supply the § The old hair falls out
epidermis with nutrients, remove waste products, and
regulate body temperature Eyelashes – grow for about 30 days; rest for 105 days
Skin Color Scalp hairs – grow for 3 years; rest for 1 – 2 years
Melanin – pigments responsible for skin, hair, eye color
Arrector Pili – smooth muscles; contraction = hair to
Melanin pigments – yellow (Caucasian), brown stand on end; produces goose bumps
(Asians), black (African)
M o r a n o , M . A .
