Thick skin, unknown magn.
- Welcome to the layers of the skin. The dermis is the pale staining
lower layer, containing connective tissue and vessels. It has projections
called the dermal papillae that interdigitate with epidermal projections
called epidermal ridges.
- The epidermis is a stratified squamous epithelium divided up
into 5 layers (the last 2 will be discussed on the next slide):
- stratum basale (germanitivum) - a single layer of basophilic
columnar or cuboidal cells resting on the basal lamina at the dermal/epidermal
junction. There are many mitoses in this layer. It is responsible for the
renewal of the epithelial cells, occuring every 15-30 days.
- stratum spinosum - cuboidal cells with filaments. They have
small cellular projections (tonofilaments) that insert into desmosomes
on neighboring cells. Role in cell cohesion, resistance to abrasion.
- stratum granulosum - flattened polygonal cells, central nuclei.
Their cytoplasm is filled with keratohyalin granules as well as EM detectable
What histological layer corresponds to our old anatomy friend:
|| Educational Computing Homepage
|| Curriculum Homepage
|| Histology Homepage
|| Histology Courseware
|| Study Modules Index ]
© New York University