Anatomy and Cell Biology 3309 Study Guide - Final Guide: Dense Irregular Connective Tissue, Stratum Corneum, Stratum Basale
22 May 2018
School
Department
Professor
Histology 3309
Lab 14
Skin, Hair, Nails
Thin VS Thick Skin
- Thin skin
o in the epidermis has 4 layers
o found all over the body
o if you see a hair follicle in a section, its automatically thin skin
- Thick skin
o Found in the palms of the hand and soles of the feet
o n the epidermis has 5 layers
o The extra layer in thick skin is called stratum lucidum
o The top layer is thicker and more compact (stratum corneum)
o Only found in palms of hand and soles of feet
o It thickening in response to walking around and using your hands all day its a very
responsive organ)
Layers of the skin
- Skin has 3 layers:
- A =most apical layer (green bracket)
o Epidermis
o Where you find the 4 or 5 layers (depending on whether its thin or thick skin)
- D = dermis (black bracket)
o Divided into 2 sublayers:
▪ Papillary layer: layer closest to the epidermis (loose connective tissue)
▪ Reticular layer: deep to the papillary layer (dense irregular connective tissue)
- H = hypodermis (big black bracket)
o Where you find a whole bunch of stuff
o The black circle at top: secretory portion of a gland
o Adipocytes
o Peripheral nerve
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find more resources at oneclass.com
o Blood vessels
o Collagen fibers etc
- Both thin and thick skin has these 3 layers (its within the epidermis where the differences are
found)
Thick Skin
- Thin skin will be the same except without the stratum lucidum
- Yellow bracket = epidermis
- Yellow outline at bottom = stratum basale
o One cell layer thick
o Cuboidal, plump cells
o Connected to the papillary layer of the dermis
o Cell body of the melanocyte will be in the stratun basale (if you can see melanocytes in
the section of cut)
- Smaller yellow bracket marked S= stratum spinosum
o You can tell bc its more than 1 layer (ranges from 5-15 cell layers thick) (depending on
where you are looking – but its always going to be more than 1 layer)
o As the cells approach the apical surface, the cells become more squamous shape
o The cells in this layers are linked together by desmosomes (macula adherens)
o With tissue preparation the cells are going to shrink but the desmosomes remain
constant (maintain their connections with each other)
o if we zoomed into the spinosum (40X) you would see a spiny appearance (like a ladder)
due to cellular shrinkage
- blue oval marked G= stratum granulosum
o 1-3 cells thick
o very dark and very basophilic bc the cells are jam packed with keratohyaline granules
(these granules are precursors to keratin)
- red outline marked L = stratum lucida
o pale, cloudy, whispy
o almost going to look negatively stained
o only seen in thick skin
o easy to identify bc prominent
- black bracket marked C = stratum corneum
o most apical layer
o jam packed with cells
o thicker and more compact in thick skin
o cells are eosinophilic due to keratin
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Thin skin in the epidermis has 4 layers found all over the body if you see a hair follicle in a section, its automatically thin skin. It thickening in response to walking around and using your hands all day (cid:523)it(cid:495)s a very responsive organ) A =most apical layer (green bracket: epidermis, where you find the 4 or 5 layers (depending on whether its thin or thick skin) D = dermis (black bracket: divided into 2 sublayers, papillary layer: layer closest to the epidermis (loose connective tissue, reticular layer: deep to the papillary layer (dense irregular connective tissue) H = hypodermis (big black bracket: where you find a whole bunch of stuff, the black circle at top: secretory portion of a gland, adipocytes, peripheral nerve, blood vessels, collagen fibers etc. Both thin and thick skin has these 3 layers (its within the epidermis where the differences are found) Thin skin will be the same except without the stratum lucidum.
