Apocrine and eccrine glands

Apocrine and eccrine glands
by Dr. Jikisha Jain (1st year resident M.D. DVL)

1. Eccrine and apocrine glands, sebaceous glands by:- Dr.Jikisha J ain

2. Sweat Glands Eccrine sweat glands Apocrine sweat glands

3. Eccrine glands They are coiled tubular glands that open directly on skin surface via sweat pores.

4. Eccrine Sweat Glands Structure Secretory coiled portion Intradermal d u ct Intraepidermal duct

5. Secretory part is present in lower dermis & contains single layer of secretory cells. Straight dermal part contains two layers of cuboidal epithelial cells and eosinophilic pseudocuticle on luminal side. Intraepidermal part is spiral and here cells are derived from dermal duct cells hence called as acrosyringium or epidermal sweat duct unit.

6. Eccrine Sweat Glands Innervation Postganglionic sympathetic fibers that have acetylcholine . Under the control of hypothalamic sweat cent re. Activated by emotional & thermal stimuli . Sites All over the body skin surface with the highest density on the palms , soles & forehead .

7. Eccrine Sweat Glands Development As a downgrowth of surface epidermis during embryogenesis No developmental relationship with the pilosebaceous fol licule

8. Eccrine Sweat Glands Function it is a secretory & excretory orga n. Secretory coil secretes (Nacl, K, bicarbonate, glucose, lactate ) Thermoregulation through the continous secretion of sweat . Maintenance of electrolyte balance . Keep the thick stratum cor neum moist to e nsure fine tactile skills & pliability of the palms & soles .

9. Eccrine Sweat Glands Disorders Hyperhidrosis Causes: emotional , neurologic, infectious, neoplastic e.g. lymphoma, hypoestrogenemia H y pohidrosis or anhidrosis Acquired: neuropathy d.t. poral occlusion in patients with scleroderma- Congenital: hypohidrotic ectodermal dysplasia, neuropathy Sweat retention Milaria ( crystallina, rubra, profunda)

10. Apocrine Sweat Glands Apocrine glands are coiled tubular glands that open in hair root above the opening of sebaceous gland or directly on the skin surface. They are larger than sweat glands and extend upto SC tissue.

11. Apocrine sweat glands Structure Secretory portion Intraepidermal duct Intradermal duct

12. Apocrine G lands Secretory portion: Single layer of secretory cells with outer layer of myoepithelial cells and lie in SC tissue. Duct: Consists of outer basal cells and inner luminal c ells.

13. Apocrine sweat glands Earlier ,it was believed that secretion is due to the separation of apical cap which was formed during the maturation of gland hence the name apocrine but now it has been established that secretion occurs due to release of cytoplasm into lumen more like merocrine gland.

14. Apocrine G lands Sites: Axillae Genital region perianal region They are present as modified glands in:- External auditory canal ( ceruminous glands) Eyelids ( glands of Moll ) Breast (mammary glands)

15. Apocrine sweat glands Innervation Postganglionic sympathetic fibers that have adrenaline. Development As an outgrowths of the upper portion of hair follicle Enlargment of the glands occur with approach of puberty under hormonal stimulation primarily androgen The glands do not begin to function until puberty

16. Apocrine sweat glands C omposition of apocrine sweat cholesterol, triglycerides, FAs,…. Obstruction→apocrine miliaria ( Fox-Fordyce disease) Apocrine sweat is sterile & odorless Bacterial decomposition leads to specific odor( bromohidrosis Chromohidrosis : secretion of pigmented sweat{ yellow, green or black)

17. Sebaceous Glands Always associated with hai r follicles except at: Eye lids ( M eibomian glands) Female areolas (Montgomery tubercules ) Prepuce (Tyson’s glands) Buccal mucosa & vermilio n borde r of lips (Fordyce ‘s spot ) sebaceous gland along with hair follicle forms a pilosebaceous unit.

18. Sebaceous glands have multiple lobules with common excretory duct.

19. Function of sebum It keeps hair & skin from becoming dry, brittle & cracked by dehydration . Can inhibit the growth of microorganisms on the skin .

20. Sebaceous Glands Sites A ll over the body except palms & soles . They are found in great abundance on the face , scalp, upper trunk ,EAC, anogenital areas. Acne patients have larger sebaceous glands & produce more sebum than patients with normal skin

21. Sebaceous Glands Development As an outgrowth from the upper portion of the hair follicle Sebum production is an indicator of androgenic activity & increases at the time of puberty

22. Sebaceous Glands 2000 birth Puberty They are fully developed at birth and gradually decrease in size to enlarge again at puberty under the influence of androgens

23. Sebaceous Glands Sebaceous glands are rich in microorganisms: Malassezia spp., staphylococcus epidermidis & propionibacterium spp. Sebum consists of : FFAs, wax sterol esters, TG & squalene

24. Sebaceous Glands Produce sebum via holocrine secretion ( the cells themselves actually disintegrate, releasing the sebum)

25. Thank you