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)
Sudoriferous - Sweat Glands
Merocrine: secrete sweat
Apocrine: secrete sweat + protein
Apocrine glands
Secrete products in hair follicles
Axilla, nipples, pubic region
Begin at puberty
Controlled by nervous system and hormones
Sebaceous gland
Secrete oil called sebum, kills bacteria on skin, lubricates and protects keratin, and conditions skin.
Sebaceous follicles are not associated with hair follicles, discharge onto the epidermis.
Protection
Chemical barriers: Acid mantle
Physical barriers:
Biological barries: dendritic cells, macrophages and DNA
Skin CA
Basal cell: most common least malignant
Squamous cell: 2nd most common, affects keratinocytes
Melanoma: least common most dangerous
Accessory structures of the integument:
hair follicles
nails
sweat glands
sebaceous glands
The portion of the hair follicles where cell division occurs s the
Matrix
Regeneration of injured skin:
1) Inflammation: bleeding and regeneration
2) Migratory phase: scab and granulation tissue formation
3) Proliferation phase: loss of granulation and undermining of the scab
4) Scarring phase
Skin Cancer A B C D
Asymmetry
Border
Color
Diameter
