Eccrine glands by Aseem

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A descript about Eccrine Glands

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Eccrine glands by Aseem

  1. 1. ECCRINE GLANDS
  2. 2. OVERVIEW • Major Sweat Glands • Primates • ‘Atrichial’ • Temp Regulation • Grip • Minor Excretory
  3. 3. ETYMOLOGY Merocrine (Gk: Meros – Part + Krinien – Separate) Sudoriferous (Lat: Sudare – Sweat Fer – to carry / bear) Eccrine (Gk : Ekkrinien – to secrete) Exocrine Glands
  4. 4. DENSITY / DISTRIBUTION • Generalized distt INCL Glans / Prepuce EXCL Vermillion Border Lip Nail Bed Clitoris / Labia Minora Ext Aud Canal 02 – 04 Million Glands / BSA 30 – 40 mcg Indl Weight (Cum – 100 g) Males > Females > Pre-pubertal Distt
  5. 5. DISTRIBUTION (Glands/cm2) • Volar 600 – 700 • Forehead 181 • Forearm 108 • Back 64
  6. 6. EMBRYOLOGY • Epidermal downgrowths in Fetal Life (Ectodermal Origin) • 03 Months – Palms / Soles • 05 Months – Other Areas • 08 Months - Adult Morphology No Post-natal development
  7. 7. DEVELOPMENT
  8. 8. STRUCTURE • SIMPLE COILED TUBULAR Glands • Spiral Intraepidermal duct (ACROSYRINGIUM) • Straight Intradermal duct UPPER DERMIS • Coiled Terminal Portion (ACINUS / FUNDUS) 2/3rd SECRETORY 1/3rd DUCTAL
  9. 9. SECRETORY COIL • 02-05 mm Uncoiled Length ; 60-80 microns Dia Large CLEAR CELLS (CC) Secretory / Pyramidal / Rest on ME Lipofuschin Autofluoroscent Granules Aqueous Substance + Glycogen House Na+ - PUMP for Active Ion Tpt
  10. 10. SECRETORY COIL • Small DARK Cells (DC) Mucoid / Cuboidal / Rest on CC PAS – positive Glycoproteins Sialomucin secretion • Myo-Epithelial Cells (ME) Spindle / Rest on BM / Support CC Myofilaments / Mechanical Support ? Propel Sweat to the surface Non-Secretory COLLAGEN-RICH HYALINE BASEMENT MEMBRANE
  11. 11. ULTRASTRUCTURE OF SECRETORY COIL
  12. 12. INTRADERMAL SWEAT DUCT • LUMINAL Cells – Inner / Small / Cuboidal / Basophilic • DUCTAL Cells – Outer (Basal) / Na – K – ATPase Activity ? Ductal Reabsorption of Sweat Tonofilament – rich Pseudo-Cuticle Rigidity
  13. 13. ACROSYRINGIUM • Intraepidermal Ductal System • Rete Ridge  Corneal Surface • Single layer of Inner Luminal Cells • 02-03 Layers of Outer Basal Cells Cells contain Desmosomes, few Melanocytes and undergo Kertainization Final Propulsion of Formed Sweat to Surface via Pore
  14. 14. FUNCTIONS • SWEATING Heat Stress – Evaporative Heat Loss (1 L  585 kCal) Emotional Stimuli Gustatory Stimuli • MOISTURIZING For Improved Grip • EXCRETION Minor / Adjunct Organ except Certain Drugs MAINTAIN ELECTROLYTE-BALANCE ANTI-MICROBIAL PEPTIDES (DERMICIDIN - ‘Sweat Antibiotic’)
  15. 15. CONTROL OF ECCRINE SWEATING 03 PHYSIOLOGICAL STIMULI THERMOREGULATORY (Hypothalamus) EMOTIONAL (?Frontal) GUSTATORY (Medulla)
  16. 16. THERMOREGULATORY MECHANISM
  17. 17. INNERVATION OF ECCRINE GLANDS • Via Efferent Sudomotor Pathway through Postganglionic non-myelinated C fibres to Eccrine Glands • SKIN SUPPLY UPPER LIMB T2 – T8 TRUNK T4 – T12 LOWER LIMB L2 – L4 • Sympathetic nerve supply - MUSCARINIC & CHOLINERGIC R • Alpha / Beta Adrenergic Receptors
  18. 18. SUDOMOTOR PATHWAY
  19. 19. THERMOREGULATION • HEAT LOSS - radiation, convection, conduction and evaporation • Thermal Sweating keeps Body Temperature constant • High environmental Temp  Evaporational Heat Loss provides maximum regulation
  20. 20. THERMOREGULATION FACTORS : LOCAL SKIN TEMP 10 deg C Rise  3X Local Sweating CORE TEMP Similar Rise  9X Local Skin Temp
  21. 21. SWEATING • CLEAR ODOURLESS ECCRINE SECRETION  PERSPIRATION • Comprises WATER + electrolytes • SWEAT RATE No of Active Sweat Glands per area X Rate of Sweating / Gland (Max 02-20 micro L / gland) • 10 L SWEAT / DAY in Acclimatized indl
  22. 22. CONTENTS • pH : 4.3 – 4.7 • WATER • Inorganic ions – sodium, chloride, potassium • Lactate / Urea (Moisturizers) • Glucose +/- • Ammonia and amino acids • Proteins including proteases
  23. 23. MECHANISM OF SWEAT PRODUCTION • 02 STEPS : (1) SECRETORY COIL  ‘ULTRAFILTRATE’ ISOTONIC FLUID i/r/o Ach (2) DUCTAL SYSTEM  REABSORBS NaCl  HYPOTONIC SURFACE SWEAT
  24. 24. • ACh stimulates EG by inc intracellular Ca2+ • Opens K+ Cl- Channels in CC  Loss of K+ Cl- H20 • Eccrine Gland Shrinkage • Na K ATPase Pump Activated to facilitate Intracellular entry of Na+ K+ Cl- • Isotonic NaCl in Lumen of Coiled Tubule
  25. 25. DUCTAL REABSORPTION • Na+ Re-Entry via Na+ Channels and Transport across BDC by Na+ K+ ATPase Pump • SWEAT ACIDIFICATION by Carbonic Anhydrase
  26. 26. OTHER FACTORS AFFECTING SWEATING • Environmental conditions(Ambient Temp / Air Velocity • Clothing (Insulation and Moisture Permeability) • Degree of Acclimatization • Physical activity level • Emotional stress
  27. 27. EXCRETORY FUNCTION • MINOR ROUTE for Water / Electrolytes / Metabolic Wastes • ACTIVE EXCRETION of DRUGS : – Griseofulvin / Ketoconazole / ?Fluconazole – Ciprofloxacin / Sulpha Drugs – Phenobarbitol / Other AEDs – ?? Chemotherapeutic Agents / DMARDs ??
  28. 28. ECCRINE GLAND DISORDERS
  29. 29. THANK YOU

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