here is my presentation on dermatology... topic: skin basic info + histo pathological changes

1. Structure of the Skin,
histopathological changes
Presentation By: Samani Raj P.
Group no.23
Submit to: Ass. Shakirova A.T.
Dermatology | Course : 03

2. SKIN (Some basics)
2
 Skin is the largest organ in the body.
 In a 70kg individual, the skin weighs over 5 kgs and
coversa surface area approaching 2 square meter.
 Human skin is of two types:
 Non hairy (glabrous)skin : as seen on palms and soles.
 Hair bearing skin

3. 3
Human Skin Consists Of:
 Epidermis
 Dermis
 Hypodermis(subcutaneous fat )

4. Cells Other structures
Epidermis Keratinocytes,melanocyte
s,langerhans cells and
merkel cells
Hair follicles,apocrine
glands and sweat glands
which are derived from
epidermisand extend to
dermis
Dermis Fibroblasts,mast
cells,histiocytes,macroph
agesand lymphocytes
Matrix of polysaccharides
and protein

5. Epidermis
 It is stratified squamous epithelium which is terminally
differentiated.
 Thickness:0.05-0.1mm.
 Keratinocytes constitute more than 95% of epidermal cells.
 The “brick like “ shape of keratinocyte is provided by
cytoskeleton madeof keratin intermediate filaments.
 As epidermis differentiates, cells gets flattened. This process involves
the filament aggregating protein called filaggrin.
 Keratin and filaggrin comprises 90% of mass of epidermis.

6. The layers of the epidermis include the stratum basale (the
deepest portion of the epidermis), stratum
spinosum, stratum granulosum, stratum lucidum,
and stratum corneum (the most superficial portion of the
epidermis).

8. The epidermis has three main types of cell:
Keratinocytes (skin cells)
Melanocytes (pigment-producing cells)
Langerhans cells (immune cells).

9. Dermis
 It makes the bulk of skin.
 Unlike epidermis , it is highly acellular and consist of extracellular matrixof connective
tissue .
 Thickness varies from 0.5mm to 5mm.
 Thereare four majorcomponents:
o Collagen fibres : providetensilestrength.
o Elastic structures: :provideelasticityand resilience .
o Glycoproteins such as fibrillins,fibulins and integrins : organizersof matrix
o Proteoglycans /glycosaminoglycans (GAGs): provide hydration.

10. Organization Of Dermis
 Dermis is organized into :
 papillarydermis
 reticulardermis
A horizontal plane of vessels marks the boundary between them.
 The papillarydermisand periadnexal dermisare together known as
adventitial dermis.

11. Hypodermis
The hypodermis (also called the subcutaneous layer or
superficial fascia) is a layer directly below the dermis and serves
to connect the skin to the underlying fascia (fibrous tissue) of the
bones and muscles.

12. Histo-pathological changes in skin

13. Hyperkeratosis
• hyperplasia of the stratum corneum
• Psoariasis, eczema.

14. PARAKERATOSIS
Keratinization pattern characterized by retention of nuclei in the stratum corneum
(this is normal on mucous membranes)

15. ACANTHOSIS
• epidermal hyperplasia
• Eczema, psoriasis

16. Acanthosis:
•Psoriasiform (regular)
•Irregular
•Papillated
•Pseudoepitheliomatous
/pseudocarcinomatous

17. Acanthosis + hyperkeratosis:

18. Papillomatosis
• hyperplasia of the papillary dermis
• Neoplastic-verrucous ca, venous stasis, viral infections etc..

19. Dyskeratosis
Abnormal keratinization – carcinoma.

20. Acantholysis
• loss of intercellular connections
• Pemphigus

21. Spongiosis
• Intercellular edema in the epidermis
• Eczema, pempigus, seborrheic dermatitis.

22. Classification: (Morphologic)
• Epidermis:
• Epithelium: Psoriasis, pemphigus, Neoplasms.
• Pigment disorders: hyper, hypo,
• Dermis:
• Blood vessels - urticaria, contact dermatitis.
• Dermal connective tissue - systemic sclerosis
• Panniculus / Sub cut tissue: erythema nodosum,
• Neoplasms – fibroma, lipoma, sarcoma ..etc.
• Ultimately both Epidermis & Dermis involved *

23. Classification (Pathologic):
• Congenital: nevi
• Acquired:
• Traumatic: chemical, physical
• Infections: Bacterial, fungal, Viral, etc.
• Immune: Urticaria, Eczema.
• Neoplastic: Nevi…carcinoma
• Idiopathic diseases : Psoriasis

24. Skin injury - Pathogenesis
Normal Urticariam Wet Eczema Dry Eczyma
Normal Hyperkeratosis

25. Thank you
Presentation By: Samani Raj P.
Group no.23
Submit to: Ass. Shakirova A.T.