Download presentation
Presentation is loading. Please wait.
1
Skin Histology Epidermis J.F. Thompson, Ph.D.
Chapter 5 Skin Histology Epidermis J.F. Thompson, Ph.D.
2
The Architecture of the Skin
2 Principal portions Epidermis - epithelium Dermis – areolar and dense irregular fibrous connective tissue Hypodermis “beneath the dermis” the subcutaneous layer next to: adipose layer or muscle or bone
3
The Epidermis Stratified Squamous Epithelium 4 cell types
Keratinocytes - 90% filled with keratin (protein) waterproof barrier Melanocytes - 8% produce melanin (pigment) pass melanin to keratinocytes Langerhans cells phagocytes (from immune system) easily damaged by UV light Merkel cells in deepest layer of hairless skin sensory transduction - touch
4
Keratinocytes and Melanocytes
5
Merkel Cells
6
Langerhans Cells
7
Epidermal Cell Layers Stratum basale Stratum spinosum
A single layer of cuboidal/columnar cells Stem cells, melanocytes, Merkel cells Stem cells keratinocytes, mitosis pushes the other layers to the top Stratum spinosum 8 to 10 layers of closely packed cells Cell junctions - spot desmosomes Langerhan’s cells
8
Epidermal Cell Layers Stratum granulosum Stratum lucidum
3-5 layers of flattened, with keratohyaline granules beginning breakdown of nucleus, cell death initiated Stratum lucidum only in thick skin (palms, feet) 3-5 layers of clear, flat dead cells with keratin Stratum corneum 20-30 layers of flattened, dead, keratin-filled cells continuously shed and replaced 2-4 weeks for each cell to form and to move from the stratum basale to the surface
9
Thin Skin
10
Thin Skin Stratum Corneum Stratum Granulosum Stratum Spinosum
Stratum Basale
11
Thick Skin
12
Skin Histology Epidermis
End Ch 5 Skin Histology Epidermis
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.