Skin Biopsy Specimen

Point and click for more information on a feature.

Features which can be seen in this image include:

• Stratum corneum, or cornified layer, of the epidermis
  • This layer consists of dead keratinocytes.
• Stratum granulosum, or granular layer, of the epidermis
  • This layer consists of maturing keratinocytes, which storing keratinohyalin.
• Stratum spinosum, or prickle-cell layer, of the epidermis.
• Desmosomal junctions should be clearly visible at high power in your microscope. It is the spiny or prickly appearance of these junctions which give this epidermal layer its name.')
• Stratum basale, or basal layer, of the epidermis
  • This layer includes mitotically active keratinocytes and melanocytes.
• Melanocytes in the basal layer of the epidermis.
  • Melanocytes are typically recognizable by the pale halo surrounding the nucleus.  This appearance results partly from pale (weakly staining) cytoplasm and partly from artifactual cell shrinkage.
  • (The cytoplasm of keratinocytes, which form the bulk of the epidermis, is much more basophilic.  Keratinocytes are also reinforced by intracellular fibers and are tightly attached to one another, so keratinocytes do not display this shrinkage characteristic.)
  • Although not obvious in this digitized micrograph, melanocytes also differ from keratinocytes in the appearance their nuclei.  Melanocyte nuclei are smaller, darker with grainier chromatin, and have less-conspicuous nucleoli.
• Connective tissue of dermis, with fibers and ground substance.
• Note the differing appearances of dermal papillae, depending on the plane of section.
• Small blood vessels.
• Many small features (such as individual fibroblasts and collagen fibers) are not individually labelled.

Comments and questions: dgking@siu.edu

SIUC / School of Medicine / Anatomy / David King

http://www.siumed.edu/~dking2/intro/skinbiop/du1SD3g2.htm
Last updated:  11 December 2007  / dgk