Eccrine glands are found all over the human body and are responsible for sweating and thermoregulation. They have a coiled secretory portion made up of clear and dark cells that secrete an isotonic fluid rich in water and electrolytes. This fluid travels through a duct system where sodium and chloride are reabsorbed, resulting in a hypotonic sweat that reaches the skin surface through acrosyringium pores. Eccrine glands are innervated by the sympathetic nervous system and sweat production is stimulated by heat, emotions, and gustatory factors to cool the body through evaporation.

1. ECCRINE GLANDS

2. OVERVIEW
• Major Sweat Glands
• Primates
• ‘Atrichial’
• Temp Regulation
• Grip
• Minor Excretory

3. ETYMOLOGY
Merocrine (Gk: Meros – Part + Krinien – Separate)
Sudoriferous (Lat: Sudare – Sweat Fer – to carry /
bear)
Eccrine (Gk : Ekkrinien – to secrete)
Exocrine Glands

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. DISTRIBUTION (Glands/cm2)
• Volar 600 – 700
• Forehead 181
• Forearm 108
• Back 64

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. DEVELOPMENT

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

10. 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

11. 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

12. ULTRASTRUCTURE OF
SECRETORY COIL

14. 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

15. 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

16. 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’)

17. CONTROL OF ECCRINE SWEATING
03 PHYSIOLOGICAL STIMULI
THERMOREGULATORY (Hypothalamus)
EMOTIONAL (?Frontal)
GUSTATORY (Medulla)

18. THERMOREGULATORY MECHANISM

19. 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

20. SUDOMOTOR PATHWAY

21. THERMOREGULATION
• HEAT LOSS - radiation,
convection, conduction and
evaporation
• Thermal Sweating keeps Body
Temperature constant
• High environmental Temp 
Evaporational Heat Loss
provides maximum regulation

22. THERMOREGULATION
FACTORS :
LOCAL SKIN TEMP
10 deg C Rise  3X Local Sweating
CORE TEMP
Similar Rise  9X Local Skin Temp

23. 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

24. CONTENTS
• pH : 4.3 – 4.7
• WATER
• Inorganic ions – sodium, chloride, potassium
• Lactate / Urea (Moisturizers)
• Glucose +/-
• Ammonia and amino acids
• Proteins including proteases

25. MECHANISM OF SWEAT PRODUCTION
• 02 STEPS :
(1) SECRETORY COIL  ‘ULTRAFILTRATE’
ISOTONIC FLUID i/r/o Ach
(2) DUCTAL SYSTEM  REABSORBS NaCl  HYPOTONIC
SURFACE SWEAT

26. • 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

27. DUCTAL REABSORPTION
• Na+ Re-Entry via Na+ Channels
and Transport across BDC by
Na+ K+ ATPase Pump
• SWEAT ACIDIFICATION by
Carbonic Anhydrase

28. OTHER FACTORS AFFECTING
SWEATING
• Environmental conditions(Ambient Temp / Air Velocity
• Clothing (Insulation and Moisture Permeability)
• Degree of Acclimatization
• Physical activity level
• Emotional stress

29. 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 ??

30. ECCRINE GLAND
DISORDERS

37. THANK YOU