MIDTERMS

• Skin is the outer covering of the body and is the largest organ of the integumentary system

  
• An inch of your skin has approximately 18 million cells and 6000 melanocytes and also 1000 nerve endings and 20 blood vessels

  
• Fitzpatrick scale or Fitzpatrick classification


  Used in 1975 to classify skin types based on skin color and its response to sun exposure, to determine proper sun protection factor or predict skin cancer risk

  
• Skin


  • In average adult, skin covers a surface area in excess of 2m2
  • With the exception of the skeletal muscles, the skin is the heaviest organ in the body
  • The skin varies in thickness between the palms and soles of the feet, where it is very thick, to the fine delicate skin on the face

  
• Fitzpatrick skin types


  • Type 1 - Light / Pale white skin tone
  • Type 6 - Brown / brown to black
• In adults, in our age, the skin covers 15% of our total body weight (e.g. 75kg person, 11kg was from the skin)
• Skin's primary physiological function

  Act as the body's first line of defense against exogenous agents
• Glabrous skin


  Non hairy skin
• The person who has more melanin has darker skin and less to develop skin cancer
• The skin should not be viewed as a flawless physicochemical barrier

  
• Normal skin


  Neither too dry nor too oily, has regular texture, no imperfections, clean and soft appearance, does not need special care
• Glabrous skin


  • Found on the palms and soles of the feet, lacks hair follicles and sebaceous glands but has a very thick epidermis and encapsulated sense organs in the dermis

  
• Dry skin


  Characterized by a feeling of tightness and roughness, may acquire an ashy gray color, with occurrence of desquamation, itching, redness and small cracks
• Oily skin


  Has a porous, humid and bright appearance, caused by excessive fat production by sebaceous glands, usually determined by genetic and/or hormonal causes
• Hairy skin


  In hairy skin, hair follicles and sebaceous glands are both present, but there are no encapsulated sensory organs
• Many low–molecular weight compounds are capable of penetrating this barrier
• Combination skin


  Presents characteristics of both dry and oily skin since the distribution of sebaceous and sweat glands is not homogeneous

  
• Sensitive skin


  More prone to react to stimuli to which normal skin has no reaction, fragile skin, usually accompanied by feelings of discomfort, such as heat, tightness, redness or itching
• When toxic agents (such as irritants or allergens in cosmetic products) permeate it, the resulting adverse effects may cause considerable discomfort to the consumer
• Facial skin has large sebaceous glands associated with fine vellus hairs, contrasting sharply with the scalp, which contains large hair follicles
• Cleanser


  Facial care product used to remove make-up, dead skin cells, oil, dirt, and other pollutants from the skin, helps unclog pores and prevent skin conditions like acne
• Thick skin


  • Thick epidermis, 0.6-4.5 millimeter, contains 5 layers (normal skin in thin skin has 4 only), lacks hair follicles, contains sweat glands

  
• Even minor disturbances of the skin surface can produce discomfort, especially in the facial area which has an extensive network of sensory nerves

  
• Using a cleanser designated for the facial skin is better than bar soap or another form of skin cleanser not specifically formulated for the face
• Facial cleansers


  • Cream cleansers
  • Foam cleansers
  • Oil cleansers
  • Clay cleansers
  • Micellar cleansers
  • Powder cleansers
  • Bar cleansers
  • Cleansing mitts/clothes/wipes
  • Charcoal cleansers
  • Honey cleansers
  • Vitamin C cleansers
• Because most cosmetics are applied to the highly permeable facial skin, the majority of reported cosmetic reactions occur in the face

  
• Thin skin


  • Thin epidermis, 0.1-0.15 millimeter, covered most of the body, four layers, hair follicles, sebaceous glands

  
• Exfoliation


  The process of removing dead skin cells from the surface of your skin using a chemical, granular substance, or exfoliation tool

  
• Skin


  • Serves as first line of defense against bacteria, viruses
  • Protects underlying structures from UV radiation dehydration
• Safety with regard to cosmetic products is a vital issue
• Exfoliating can improve the appearance of your skin by leaving it looking brighter, improving the effectiveness of topical skin care products, preventing clogged pores, and increasing collagen production

  
• Contact Dermatitis


  A nonspecific term used to describe any inflammatory skin disease resulting from contact with an irritant or allergenic substance
• Mechanical exfoliation


  Physically scrubbing the skin with an abrasive
• Vitamin D production


  Skin starts as a precursor to dehydro-cholesterol before it became vitamin D, needed to be absorbed to UVB – after absorbed it will convert to vitamin D3. Vitamin D3 will be metabolized to Kidney by hydroxy vitamin produce dihydroxy vitamin -> converted to Vitamin D (calcitriol – active form of Vit D ones needed to calcium absorption)
• Chemical exfoliation


  Using products containing salicylic acid, glycolic acid, fruit enzymes, citric acid, or malic acid to loosen the glue-like substance that holds dead skin cells together

  
• Alpha hydroxy acids (AHAs)


  Water-soluble acids that gently loosen the upper layer of the skin producing a peeling action or exfoliation, help fade pigmented spots, rough or bumpy patches, and hyperpigmentation
• Whatever the causative agent, the clinical features of contact dermatitis are similar: itching, redness, and skin lesions

  
• Vitamin D is the only vitamin that our body can produce naturally
• Beta hydroxy acids (BHAs)


  Oil-soluble acids that go deeper into the pores than AHAs to clear excess debris and sebum
• Sensation


  Sensory receptors, feeling of itchiness and pain etc