THE SKIN By P.D.Sanaa El-Sherbiny Mansoura University
Function of theskinand protects the body. Covers Control internal temperature. Produces vitamin D. Receptors to detect...
Skin structure Epidermis: is outermost layer. Stratified squamous keratinized epithelium.   Keratinization production o...
Types:1-THICK SKIN EPIDERMIS IS THICK:0.8mm in palm ,1.4    mm in sole.   Contains 4 types of cells:   1-keratinocytes ...
Epidermis anddermis         Epidermis (purple)           Dermal papillae         Dermis         •Superficial papillary lay...
Layers of epidermis are           Stratum basale           (germinativum)           Stratum spinosum           Stratum ...
Layers of epidermis             Stratum basale             (germinativum)               Single layer of cells on basal  ...
Layers of epidermis             Stratum spinosum              Several cells thick              Have cytoplasmic process...
Layers of epidermis              Stratum              granulosum                1 to 3 layers of fusiform               ...
Layers of epidermis             Stratum             lucidum              Present only in               thick skin       ...
Layers of epidermis                Stratum corneum                    Superifical keratinized layer                    ...
TYPES OF EPIDERMAL CELLS
The epidermal cells:1-keratinocytes                They are responsible                For keratin                 forma...
:Melanocytes Found inbetween cells of the basal layer & At the basal part of the hair follicles. Branched cells with ce...
:Langerhans cells -3 Found in upper layers of st.spinosum Have branched shape &central nuclei Represent 3-8%of epid. Ce...
Langerhans cells
Merkels cells-4 Found in basal cell layer Are modified epidermal cells Sensory nerve fibers                  form  term...
THIN SKIN ALLOVER THE BODY EXCEPT SOLE & PALMS. EPIDERMIS  ISTHINNER,ST.spinosum,2-4LAYERS,ST.GRA.  ONE INCOMPLETE LAY...
THIN SKIN
The dermis 1-Papillary layer : Forms dermal papillae Loose C.T rich in collagen type 111 Elastic fibers,C.T cells and ...
Meissner‘s )Tactile( Corpuscle Located in the dermlpapillae Receptor for light touch       28
Reticular layer -2 The thicker deep layer Formed of dense c.T rich in interlacing wavy    collage fibers   It is less c...
:Glands and skin appendages Sebaceous glands   Clumps of epithelial tissue distributed within dermis   Secrete “sebum”—...
sweat glands         Two types of sweat glands             Eccrine                Not associated with hair follicle     ...
SWEAT GLANDS Merocrine glands:              Apocrine glands: Allover the body               Axilla,groin,pubic Secret...
Histology (Skin) - Part 1
Histology (Skin) - Part 1
Histology (Skin) - Part 1
Histology (Skin) - Part 1
Histology (Skin) - Part 1
Histology (Skin) - Part 1
Histology (Skin) - Part 1
Histology (Skin) - Part 1
Upcoming SlideShare
Loading in …5
×

Histology (Skin) - Part 1

6,125
-1

Published on

0 Comments
9 Likes
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total Views
6,125
On Slideshare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
432
Comments
0
Likes
9
Embeds 0
No embeds

No notes for slide

Histology (Skin) - Part 1

  1. 1. THE SKIN By P.D.Sanaa El-Sherbiny Mansoura University
  2. 2. Function of theskinand protects the body. Covers Control internal temperature. Produces vitamin D. Receptors to detect environmental stimuli. Regulates the movement of substances into and out of the body Forms the largest organ of the body forms 16%of body weight Bio 130 Human Biology
  3. 3. Skin structure Epidermis: is outermost layer. Stratified squamous keratinized epithelium.  Keratinization production of a waterproof protein.  Pigments. Dermis: living portion of skin mostly dense connective tissue.  Contains :C.T fibers &cells ,vessels, sweat glands, sebaceous glands, hairs. Hypodermis :Adipose tissue Contains receptors Bio 130 Human Biology
  4. 4. Types:1-THICK SKIN EPIDERMIS IS THICK:0.8mm in palm ,1.4 mm in sole. Contains 4 types of cells: 1-keratinocytes (85% of cells) 2-Melanocytes 3-Langerhans cells 4-Merkel cells ِArranged in five layers.
  5. 5. Epidermis anddermis Epidermis (purple) Dermal papillae Dermis •Superficial papillary layer contains loose connective tissue, blood vessels, nerves, and lymphatics •Deeper reticular layer has dense fibrous irregularly arranged connective tissue
  6. 6. Layers of epidermis are  Stratum basale (germinativum)  Stratum spinosum  Stratum granulosum  Stratum lucidum (may not be present)  Stratum corneum
  7. 7. Layers of epidermis  Stratum basale (germinativum)  Single layer of cells on basal lamina  Stem cells which give rise to keratinocytes  Contain melanin transferred from melanocytes  May see mitotic figures  Desmosomes and hemidesmomes
  8. 8. Layers of epidermis  Stratum spinosum  Several cells thick  Have cytoplasmic processes (spines)  Desmosomes
  9. 9. Layers of epidermis  Stratum granulosum  1 to 3 layers of fusiform shaped basophilic cells  Keratohyalin granules contain cystine-rich and histidine-rich proteins that associate with keratin filaments
  10. 10. Layers of epidermis  Stratum lucidum  Present only in thick skin  Cells in which keratinization is advanced
  11. 11. Layers of epidermis  Stratum corneum  Superifical keratinized layer  Cells  Almost filled with keratin  Flattened, non nucleate  Coated with extra-cellular lipids that form water barrier of skin  Layer that varies most in thickness
  12. 12. TYPES OF EPIDERMAL CELLS
  13. 13. The epidermal cells:1-keratinocytes  They are responsible  For keratin formation  Formed of many layers that continuously shed  And regenerate every 2-4 weeks  They are arranged  In many layers.
  14. 14. :Melanocytes Found inbetween cells of the basal layer & At the basal part of the hair follicles. Branched cells with centeral nuclei By EM contains organells for protein synthesizes (rER, Golgi, mitochondria &melanosomes). They form melanin by tyrosinase from tyrosine amino acid By converting it to dioxyphenyl alanine DOPA
  15. 15. :Langerhans cells -3 Found in upper layers of st.spinosum Have branched shape &central nuclei Represent 3-8%of epid. Cells Mesodermal in origin. EM not connected to keratinocytes & contain Birbeck granules Stained with silver & vital stains Phagocytic & antigen presenting cells
  16. 16. Langerhans cells
  17. 17. Merkels cells-4 Found in basal cell layer Are modified epidermal cells Sensory nerve fibers form terminal disk under Merkels cells Function as touch receptors
  18. 18. THIN SKIN ALLOVER THE BODY EXCEPT SOLE & PALMS. EPIDERMIS ISTHINNER,ST.spinosum,2-4LAYERS,ST.GRA. ONE INCOMPLETE LAYER:NO ST LUCI. ,ST,COR.THINNERNUMEROUS SWEAT GLANDS.*CONTAIN HAIRE, SEBACEOUS GLANDS*AND ERECTOR PILLI MUSCLE
  19. 19. THIN SKIN
  20. 20. The dermis 1-Papillary layer : Forms dermal papillae Loose C.T rich in collagen type 111 Elastic fibers,C.T cells and rich in blood capillaries Contain meisssners corpuscles
  21. 21. Meissner‘s )Tactile( Corpuscle Located in the dermlpapillae Receptor for light touch 28
  22. 22. Reticular layer -2 The thicker deep layer Formed of dense c.T rich in interlacing wavy collage fibers It is less cellular &less vascular Contain many nerve receptors: Krause end bulbs Ruffini corpuscles Pacinian corpuscles
  23. 23. :Glands and skin appendages Sebaceous glands  Clumps of epithelial tissue distributed within dermis  Secrete “sebum”—oily, fat-based substance that is also anti-bacterial  Located all over body Sweat glands  Microscopic clumps of epithelial tissue distributed within dermis, duct extends out through dermis to pore their secretion.  More than 2.5 million glands per person  Eccrine sweat glands, concentrated on hands and soles of feet and forehead, secrete sweat to cool body, also at conditions of fear and emotion.  Apocrine glands, concentrated in armpits and groin, analogous with sexual scent glands of other animals, odor comes from bacteria that concentrate here.  Ceruminous glands: modified sweat glands in ear canal produce ear wax
  24. 24. sweat glands Two types of sweat glands  Eccrine  Not associated with hair follicle  Duct segment  less coiled, leads to epidermis  Stratified cuboidal epithelium  Secretory segment  in deep dermis or hypodermis  Secretory cells  Myoepithelial cells lie between secretory cells, contraction expels sweat  Apocrine  Found in limited areas  Empty into hair follicle
  25. 25. SWEAT GLANDS Merocrine glands:  Apocrine glands: Allover the body  Axilla,groin,pubic Secretory cells 2types region Clear cells cubical rich in  Secretory part similar glycogen granules.  To mero. With wider Dark with narrow basal part with apical  Lumen Glycoprotein granules  Their ducts are lined Myoepithelialt cells  With 2 layers of cubical cells Ducts lined by 2layers of but open into hair follicles cubical cells  Secretion stim.by sex  hormons
  1. A particular slide catching your eye?

    Clipping is a handy way to collect important slides you want to go back to later.

×