Skin Skin Color - Department of Anthropology - The University of
The skin#
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Transcript of The skin#
Thick skinFormed of
epidermis & dermis.
The epidermis keratiniezed str.sq.epith
formed of. Keratinocytes & non Keratinocytes
The Keratinocytes:85% of cells of epidermis form keratin 5 layers .
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•Basal layer together with Spinous layer are called malpighian layer
Basal cell layer or Germinal l. LM: •Single layer of columnar cells resting on clear wavy basement membrane . Have basal oval nucleus & basophilic Cytoplasm. •The nuclei show mitotic figures for renewal which take place every 2-4 weeks mostly at night .
EM: •Cells are joined together by “desmosomes” • to the basement membrane by “hemidesmosomes”. •Rich in ribosomes and polysomes
Spinous layer or Prickle cell l. LM:
•4-8 layers of polyhedral cells with central and rounded nuclei.•They have spine-like processes indicating sites of desmosomes as cells shrink during preparation.
EM:•The cells are joined by “desmosomes” & have interdegitating cell membrane.•The superficial cells contain membrane bound (coated) lamellar granules.•Langerhans cells are present in this layer