ANATOMY & PHYSIOLOGY
lecture
INTEGUMENTARY SYSTEM Melanocytes in stratum basale (produce melanin
pigment).
Functions of Integumentary System
Merkel cells
● Protection from: bumps, acids/bases, microbes, UV rays, heat/cold, drying in stratum basale (touch receptors).
out.
● Prevents water loss
● keeps essential molecules inside the body. Epidermal dendritic cells throughout epidermis (immune
defense).
EPIDERMIS (Outerlayer)
Desmosomes between keratinocytes (hold cells
together).
● Found as the outermost layer of skin.
● Made of keratinocytes = keratinization forms a protective barrier. Melanin granules inside melanocytes and keratinocytes.
LAYERS (DEEP to SUPERFICIAL)
DERMIS (Middle layer)
● Stratum basale – deepest layer, next to dermis; constant cell division.
● Strong connective tissue
● Stratum spinosum – just above basale; cells start keratinization.
● supports epidermis
● Stratum granulosum – middle layer; keratinized, flattened cells.
● Stratum lucidum – only in thick, hairless skin (palms of hands, soles of feet).
Regions:
● Stratum corneum – outer layer (exposed surface of skin); thick protective
barrier. ● Papillary layer → upper dermis (fingerprints, touch receptors).
● Reticular layer → deeper dermis (blood vessels, sweat/oil glands, deep
SPECIAL CELLS
pressure receptors).
● Elastic fibers → throughout dermis (provide elasticity).
SPECIAL CELLS LOCATION ● Blood vessels → dermis (for thermoregulation).
lecture
INTEGUMENTARY SYSTEM Melanocytes in stratum basale (produce melanin
pigment).
Functions of Integumentary System
Merkel cells
● Protection from: bumps, acids/bases, microbes, UV rays, heat/cold, drying in stratum basale (touch receptors).
out.
● Prevents water loss
● keeps essential molecules inside the body. Epidermal dendritic cells throughout epidermis (immune
defense).
EPIDERMIS (Outerlayer)
Desmosomes between keratinocytes (hold cells
together).
● Found as the outermost layer of skin.
● Made of keratinocytes = keratinization forms a protective barrier. Melanin granules inside melanocytes and keratinocytes.
LAYERS (DEEP to SUPERFICIAL)
DERMIS (Middle layer)
● Stratum basale – deepest layer, next to dermis; constant cell division.
● Strong connective tissue
● Stratum spinosum – just above basale; cells start keratinization.
● supports epidermis
● Stratum granulosum – middle layer; keratinized, flattened cells.
● Stratum lucidum – only in thick, hairless skin (palms of hands, soles of feet).
Regions:
● Stratum corneum – outer layer (exposed surface of skin); thick protective
barrier. ● Papillary layer → upper dermis (fingerprints, touch receptors).
● Reticular layer → deeper dermis (blood vessels, sweat/oil glands, deep
SPECIAL CELLS
pressure receptors).
● Elastic fibers → throughout dermis (provide elasticity).
SPECIAL CELLS LOCATION ● Blood vessels → dermis (for thermoregulation).
