Histology of Integumentary System Flashcards
integument
aka skin = cutaneous membrane
derma
skin
Integumentary System
organ because takes on more than one type of tissue
- largest in the body
includes: skin and derivatives (hair, nails, and glands)
Fans of Integumentary System
- protection (keeps stuff out, abrasion, toxins (if substance is fat soluble then it can move across skin)
- Hydroregulation- prevention in water loss
- temperature regulation- sweat glands and blood vessels
- vitamin D synthesis
- immune response
- sensory reception
- excretion (glands, lose sweat)
Two tissue layers
Epidermis and Dermis
Dermis
hypodermis aka subcutaneous layer
-mostly fat and areolar CT
Subcutaneous layer
connects skin to muscle
Epidermis (general)
- cells are keratinized squamous epithelium
- thickness varies 4-5 recognizable layers
- most cells are dead:deepest are alive (stratum basale)
- hairs and glands arise from epidermis that extends into dermis
Epidermal Layers (deepest to most shallow)
Stratum Basale Stratum Spinosim Stratum granulosum Stratum lucidum Stratum corneum (outermost)
Stratum Basale
- one layer of cuboidal cells on basement membrane
- main cell typesKeratinocytes- alive and produce keratin (constantly divides) -stem cells—-cells die as keratin accumulates (they end up in all cell layers)Melanocytes: produce pigment melanin; protects vs UVR (single cell pigment)Tactile Cells (merkel cells)- close contact with nerve ending
Stratum Spinosim
Some cell division- immune response cells (dendritic cells)
Stratum granulosum
keratinization begins here, and cells begin to die (immune response)
Stratum lucidum
in thick skin only not necessarily a callus
Stratum Corneum (outermost)
Cornfield cells (dried and flattened keratinized cells); are dead 20-30 layers of cells
- especially thick on palms of hands and soles of feet
- forms calluses and nail
Dermis (general)
Irregular dense CT- made of collagen fibers and some areolar CT
- Deeper and thicker layer than epidermis
- Dermal papillae interface with epidermal ridges
- Fingerprints and toe prints are caused by friction ridges
-CONTAINS: blood vessels, nerves, glands, hair follicles, and arrestor pili muscles
Glands in Dermis
Sweat Glands
Mammory Glands
Sebaceous Glands
Ceruminous glands
Sweat Glands
sudoriferous glands
Mammary Glands
specialized sweat glands
Sebaceous Glands
produce sebum (lipid material) makes sebum and oils and lubricates
Ceruminous Glands
Cerumen (ear wax) lubricates ear drum
