Anatomy Of The Skin Lecture

Anatomy Of The Skin Lecture

• 1.
  Anatomy of theSkinChapter 6 Prepared by: Lesley CastleFor the Baltimore School of MassageSeptember 30, 2009
• 2.
  What is containedin an inch of the skin?Millions of cells (9,500,000)Intricate network of blood vessels (19 yards)Nerves (78 yards)Pores for Sebaceous glands (95 -100)Pores for Sweat glands (650)65 hairsNerve endings to record pain (1,300)Sensory cells at the end of nerve fibers (19,500)Sensory apparatuses for heat (78)Sensory apparatuses for cold (13)Pressure Apparatuses (160 – 165)
• 3.
  Divisions of theSkin
• 4.
  Epidermis – cuticleor scarf skinEpidermis protects the delicate tissues of the body from injuryEpidermis is made of soft keratin, a proteinSoft keratin is found in the epidermis as flattened cells, or dry scalesOutermost layer of the skin; sheds daily with completely new cuticle layer by 28th day; tightly packed, scale like cells; turnover slows with age
• 5.
  Epidermis – cuticleor scarf skinContains no blood vessels, but has many small nerve endingsDispute over how many layers in epidermis, between 4 - 6Bottoms layers are sometimes classified together, known as the basal layerFor our purposes, there are 4 main layers in epidermis
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  Epidermis layers (4main + 2)1. Stratum corneum: horny layer; tightly packed, scale-like cells, continuously shed & replaced2. Stratum lucidum: clear layer; small, transparent cells through which light can pass (only on hands and feet; not present where there are hair follicles); horny zone3. Stratum granulosum: granular layer; cells that look like distinct granuals; these cells are dying; horny zone4. Stratum spinosum: basal layer - prickle cell layer; as cells undergo mitosis below, they are pushed upward into this layer; begins basal layer5. Stratum mucosum: basal layer - also called stratum germinativum, but stratum germinativum refers to lowest row of cells to make up basal layer; basal zone (living stratum)6. Stratum Germinativum: basal layer - composed of single layer of cells, lowest layer of cells to make up living stratum or basal layer; mitosis happens here and cells begin journey to surface, to replace older cells that are shed; approximately 28 days for journey; pigment granules produced here (melanocytes) to give skin color1.2.3.4.5.6.
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  Dermis – dermaor true skinMade of collagen and elastin (protein fibers); gives skin strength, form, flexibilityBlood vessels, fat cells, oil and sweat glands held together by collagenThickest layer of connective tissue; binds epidermis to subcutaneous tissueNetwork of nerves, blood and lymph vessels provide nutrition to itself and epidermisVital functions of skin; composed of sweat and oil glands, blood & lymph vessels, nerve fibers, sensory receptors, hair folliclesArrectorpili muscles (tiny muscles, generates heat when body is cold, contracts, causing hair to "stand up straight" on skin)Papillae (small, cone shaped projections of elastic tissue that point upward), contain nerve fiber endings for sense of touch
• 8.
  Dermis – 2layers1. Papillary Layer: superficial layerLies directly beneath epidermisHouses nerve endings (corpuscles) that provide body with sense of touch – pain, heat, cold, pressure, touchContains papillae, small, cone shaped projections of elastic tissue that point upwards Papillae contain looped capillaries or nerve fiber endings2. Reticular Layer: deeper layerContains fat cells, blood and lymph vessels, oil and sweat glands, hair follicles, arrectorpili muscles
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  Subcutaneous TissueFatty layer;attaches dermis to underlying structuresAlso called adipose, or subcutis tissueComposed of adipose and connective tissueServe as shock absorbers for vital organs, stores energyVaries in thickness according to age, sex, general health of individualGives smoothness, contour to body, contains fats for use as energy, heat insulatorCirculation is maintained by network of arteries, and lymphatics (removes bacteria and foreign materials, produces antibodies to fight infection)
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  How Skin isNourishedBlood and lymph supply nourishment to skinContribute essential materials for growth, nourishment, and repair of skinSubcutaneous arteries and lymphatics send smaller branches to hair follicles, skin glands, hair papillaeSkin “breathes” by taking in oxygen and discharging carbon dioxide
• 11.
  Thank you foryour Interest!Any questions?