Integumentry Ch 5 Flashcards
Epidermis
Keratinized stratified squamous epithilium with 4 cell types and 5 layers
(4 in thin skin)
4 cell types
Keratinocytes
Melanocytes
Dendrintic ( Langerhans cells)
Tactile (Merkel cells)
Keratinocytes
Produce keratin that gives epidermis its protective property. Most abundant epithelial cells.
Melanocytes
Spider shaped, synthesize pigment melanin.
Dendritic Cells
Langerhans cells, arise from bone marrow and migrate to epidermis. Ingest foreign substances and are key in immune defense.
Merkel Cell
Tactile, present at epidermal/dermal junction
Layers of the epidermis
Statum: Basal Spinosum (prickly layer) Granulosum Lucidium (clear layer) Cornuem (horny layer)
Layers of the Dermis
2nd major skin region
Papillary layer:Areolar connective tissue
Reticular layer:Dense fibrous connective tissue
Cleave tension lines
separations or less dense regions
Flexure lines
Skin markings, dermal folds that occur near joints
Skin color pigments:
Melanin, Carotene and Hemoglobin.
Hair
Hard kerotinized cells, do not flake off, strong and durable.
3 concentric layers of hair
Medulla: central core, soft keratin (matrix below produces hair)
Cortex: bulky, hard, layer surrounding the medulla
Cuticle : outermost
2 types of hair
Vellua: pale, fine, body hair
Terminal:coarse long hair of eyebrows and scalp
2 types of glands
Sebaceous (Oil)
Sudoriferous (Sweat Glands)
