INTEGUMENTARY SYSTEM

• INTEGUMENTARY SYSTEM


  an organ system composed of the skin and its associated structures, including hair, nails, sweat glands, and sebaceous (oil) glands.
• SKIN


  the largest organ of the body. it is the first line of defense. Made up of 2 major tissue layers: EPIDERMIS & DERMIS
• EPIDERMIS


  the outermost layer of the skin Consists of 5 layers: STRATUM CORNEUM, STRATUM LUCIDUM, STRATUM GRANULOSUM, STRATUM SPINOSUM, and STRATUM BASALE
• KERATINIZATION


  the process by which keratinocytes, specialized epithelial cells found in the skin, undergo maturation and produce the protein keratin.
• AVASCULAR & ANEURAL


  does not contain blood vessels & nerves
• SPECIAL CELLS: MELANOCYTES


  produces melanin, which is responsible for skin color/ pigmentation
• SPECIAL CELLS: LANGERHANS CELLS


  immune cells
• SPECIAL CELLS: MERKEL CELLS


  they are involved in the perception of mechanical stimuli such as pressure and touch.
• STRATUM BASALE


  the deepest layer of the epidermis. Mitosis is active in this layer
• STRATUM SPINOSUM


  second deepest layer. keratinization takes place.
• KERATIN


  a type of protein that makes our skin tough
• STRATUM GRANULOSUM


  its texture- LAMELLAR GRANULES, an indication that the skin cell already has keratin within it. It plays a crucial role in forming and maintaining the skin's barrier function.
• STRATUM LUCIDUM


  • thinner cells; 50% alive skin cells, 50% dead skin cells
  • Found only in the thick skin of the palms and soles, this thin, clear layer helps reduce friction between the stratum granulosum and the stratum corneum.
• STRATUM CORNEUM


  the superficial layer of the epidermis. Dead cells filled with keratin
• MELANOCYTE


  produces melanin, which protects the skin from UV radiation
• MELANOSOMES


  a vesicle that comes from golgi apparatus of melanocytes
• SKIN PROBLEMS: ALBINISM


  A recessive genetic trait that causes a deficiency or an absence of melanin.

  
• SKIN PROBLEMS: VITILIGO


  a disease in which the pigment cells of the skin, melanocytes, are

  destroyed in certain areas.

  
• SKIN PROBLEMS: DANDRUFF


  Excessive sloughing (removal) of stratum corneum cells
• SKIN PROBLEMS: CALLUS


  Thickened area of the stratum corneum due to friction.
• DERMIS


  the thickest layer of the skin. Specialized cells: FIBROBLASTS, ADIPOCYTES, MACROPHAGES
• FIBROBLASTS


  produces collagen; a tough protein
• ADIPOCYTES


  adipose cells
• MACROPHAGES


  defensive cells
• LAYERS OF DERMIS: PAPILLARY LAYER


  has folds on its surface. The reason for fingerprints & footprints
• LAYERS OF DERMIS: RETICULAR LAYER


  the deepest layer of the dermis. Flesh of the skin. when it is stretched, it can not go back to its original form (stretch marks).
• HYPODERMIS 


  MINOR LAYER. also known as subcutaneous tissue. attaches skin to the underlying muscles & bones; Insulation; energy storage.
• EXOCRINE


  has a duct system. classified as: HOLOCRINE, MEROCRINE, and APOCRINE
• HOLOCRINE


  release their secretions by the entire cell disintegrating

  
• MEROCRINE


  release their secretions without loss of cellular material

  
• APOCRINE


  release their secretion along with portions of the cell's cytoplasm

  
• ENDOCRINE


  direct secretion
• SEBACEOUS GLANDS


  produces sebum (oil), a white substance rich in lipids (fats)
• SUDORIFEROUS GLANDS


  produces sweat. May be ECCRINE or APOCRINE
• ECCRINE


  sweat contains water & excess salts (ex: palms and soles of feet)
• APOCRINE


  sweat not only contains water and excess but also contains biomolecules
• HAIR SHAFT


  above skin surface; dead skin keratinized cells

  
• HAIR BULB & ROOT


  bulb- base of hair root. located beneath the skin
• HAIR PAPILLA 


  produces hair cells
• NAILS


  A thin plate consisting of dead stratum corneum cells that contain a very hard type of keratin.