Integumentary system


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Integumentary system

  1. 1. Integumentary System Main functions Organs/parts/cells and their functions Diseases and disorders
  2. 2. Main functions Multiple roles in homeostasis(e.g. temperature change, dehydration) Protects against invasion of infectious organisms, sunburn Protects the body’s internal tissues and organs Maintains the body’s form Generates vitamin D Stores fats, water, glucose and vitamin D
  3. 3. Major organsHairSkin Nail
  4. 4. Skin Its your bodys largest organ Average surface area 1.8-2.0m² (19.4-21.5ft² ) Releases around three gallons of sweat in a hot day There are at least five types of receptors in the skin thatrespond to pain and to touch White skin appeared just 20,000 to 50,000 years ago, asdark-skinned humans migrated to colder climes and lostmuch of their melanin pigment.
  5. 5. Three layers or structures of the skin Epidermis Dermis and hypodermis Sweat and oil glands; hair and nails
  6. 6. Epidermis cornified layer(stratum corneum) clear/translucent layer(stratum lucidum, onlyin palms and soles) granular layer(stratum granulosum) spinous layer(stratum spinosum) basal/germinal layer(stratum basale/germinativum)
  7. 7. Cells of epidermis 95% cells are keratinocytes Major function is the defense against environmental damage(pathogens, heat, UV radiation and water loss) Melanocytes ( melanin-producing cells ) Langerhans cells (antigen-presenting immunecells) Merkel cells (oval receptor cells ) Inflammatory cells (a cell participating in theinflammatory response to a foreign substance. )
  8. 8. First and last layers of epidermis basal/germinal layer Cell growth of keratinocytes, attached to basementmembrane. Melanocytes and Merkel cells also can be foundin this layer. cornified layer Keratinocytes are presented at final step of differentiation(corneocytes), surrounded by keratin proteins envelope. Mostof the barrier function are here
  9. 9. DermisTwo layers: Stratum papillare and Stratum reticulare
  10. 10.  Stratum papillare This region is composed of loose connective tissue withnetwork of blood capillaries and Meissners corpuscles(type of mechanoreceptors sensitive to light touch) Stratum reticulare Is composed of dense irregular connective tissue withcollagen, elastic and reticular fibers (strength, extensibility,and elasticity)
  11. 11. Hypodermis
  12. 12. Hypodermis orsubcutaneous tissue In hypodermis fibroblasts, adipose cellsand macrophages can be found Is used mainly for fat storage In arthropods, the hypodermis is an epidermallayer of cells that secretes the chitinous cuticle
  13. 13. Glands of skin Sebaceous Glands Sweat Glands Ceruminous glands Mammary Glands
  14. 14. Sebaceous Glands Secrete an oily/waxymatter, called sebum,to lubricate andwaterproof the skinand hair Greatest abundance onthe face and scalp
  15. 15. Sebaceous Glands Diseases Acne Hyperplasia - disorder of the sebaceousglands in which they become enlarged Sebaceous cysts Sebaceous adenoma - a slow-growing tumour Sebaceous gland carcinoma -aggressive malignant cutaneous tumor
  16. 16. Sweat Glands Apocrine Eccrine
  17. 17. Apocrine glands produce a viscous andodorous secretion.They begin secreting atpuberty discharge in the canalsof hair follicles may alsocontain pheromones
  18. 18. Eccrine glands smaller than apocrinesweat glands, andthey do not extend asdeep into the dermis discharge theirsecretions directlyonto the surface ofthe skin• highest density (>250 glands/cm2) being on soles,palms, and scalp
  19. 19. Sweat Glands Diseases Hidradenitis - The inflammation of asweat gland (usually of the apocrine type) Hyperhidrosis - Excessive sweating Hypohidrosis - diminished or absentperspiration Miliaria - A syndrome of cutaneouschanges associated with sweat retentionand extravasation of sweat at differentlevels in the skin.
  20. 20. Ceruminous glands specialized sweat glands located in hypoderm drain into the guard hairs produce cerumen, or earwax, by mixing their secretion with sebum and dead epidermal cells 
  21. 21. Ceruminous glands diseases Benign tumors (e.g. ceruminous adenoma - tumour of the external auditory canal in adults, 1% of all external ear tumors) Malignant tumors (e.g. Mucoepidermoid carcinoma - most common type of malignancy in adults. Can also be found in other organs, as bronchi, lacrimal sac and thyroid.
  22. 22. Mammary Glands An organ in women that produces milk Milk is produced by cuboidal cells surrounded by myoepithelial cells – thin layer above the basement membrane
  23. 23. Mammary Glands Diseases Fat necrosis - firm nodule in the breast Fibrocystic change - most common disorder Gynecomastia - bilateral breast enlargement in the male  Fibroadenoma:  most common benign tumor Breast cancer - most common type of cancer in women   
  24. 24. Some other common SkinDiseases Melanoma Eczema Otitis Externa Skin Cancer
  25. 25. Hair facts The fastest growing tissue in the body  90% of scalp hairs are growing and 10% are resting  Female hair grows more slowly  Lifespan of hair: 2 to 7 years  A single hair has a thickness of 0.02 - 0.04mm  The average scalp has 100,000 hairs  It is normal to lose 100 hairs per day from the scalp  A single hair can support up to 100 grams in weight and a whole head of hair could support up to 12 tonnes - the equivalent of two African elephants!
  26. 26. Hair Parts the hair root the hair shaft   Hair is composed primarily of proteins (88%). These proteins are of a hard fibrous type known as keratin.
  27. 27. Hair root Is surrounded by a pouch like structure called hairfollicle  The terminal part of the hair follicle is called a hairbulb (formed by actively growing cells )• consist of: • Fibrous connective tissue• External/internal root sheath 
  28. 28. Hair root At the base of each hair bulb is the dermalpapilla containing a vessel tuft (essential for the nourishment of the growing hairs).  Melanocytes – produce pigment melanin.  Receptors for the male hormones - androgens, are located on the cells of this structure. 
  29. 29. Hair shaft The newly divided hair cells in bulb push the previous cells up. The cells, which move upwards, die slowly forming hard hair shaft.  Has three layers: Cuticle Medulla Cortex
  30. 30. Hair diseases and disordersMainly associated with the follicles ofthe hair Hypertrichosis - an abnormalamount of hair growth on the body Alopecia Areata - one of the mostprevalent hair loss diseases
  31. 31. Nails Actually the same as hair Nails grow at the rate of 0.1 mm daily Womens nails grow slowly Toe nails are about twice thicker than finger nails The fastest growing nail is on the middle finger.The slowest – on the thumbnail Nails reflect your health status
  32. 32. (I) Nail structure 6 parts: The root (germinal matrix) - produces most of thevolume of the nail and the nail bed. Nail bed (sterile matrix) - part of the nail matrix.Contains the blood vessels, nerves, and melanocytes.Adds material to the undersurface of the nail making itthicker Nail plate - actualfingernail, made oftranslucent keratin
  33. 33. (II) Nail structure 6 parts : Eponychium (cuticle) – fuseskin and nail plate, providingwaterproof barrier Perionychium (paronychialedge) - the skin that overliesthe nail plate on its sides Hyponychium -the areabetween the nail plate and thefingertip
  34. 34. Nail diseases Fungal infection(Onychomycosis) Beaus Lines Nail Lifting (Onycholysis) Nail Splitting(Onychoschizia) Bacterial infection(Paronychia)
  35. 35. Integumentary System Functions Multiple roles in homeostasis(e.g. temperature change, dehydration) Protects against invasion of infectious organisms, sunburn Protects the body’s internal tissues and organs Maintains the body’s form Generates vitamin D Stores fats, water, glucose and vitamin DSkinHairNail
  36. 36. Thank you for your attention!
  37. 37. Sources