2.1 The Skin Flashcards
5 Epidermis Layers
- Horny layer – stratum corneum
- Clear or translucent layer – stratum lucidum
- Granular layer – stratum granulosum
- Prickle cell layer – stratum spinosum
- Germinal or basal layer – stratum germinativum
2 Dermis Layers
- Papillary layer – stratum papillare
- Reticular layer – stratum reticulare
outer layer
Epidermis
it is also called squamous since superficial layers of cells have become flat and scaly
Epidermis
composed of several thicknesses of degenerated cells that have become mere scales with no cellular structure
Horny layer or outer layer
consists of tiers of cells that have lost their nuclei and cellular outlines die to the degenerative process
Translucent or clear layer
composed of two or three tiers of flattened cells containing granules
Granular layer
consists of several tiers of many-sided cells
Prickle cell layer
consists of a layer of columnar cells that forms the deepest part of the epidermis
Germinal or basal cell layer
contain a pigment that determines the darkness of skin
Germinal or basal cell layer
corium, or true skin
Dermis
it is composed of loose (areolar) connective tissue with widely separated cells, with fibrous bands and elastic tissue fibers between
Dermis
its outer surface is elevated into tiny projections with hollows between them
Papillary layer
the cells and fibers form an interlacing network
Reticular layer
blood vessels and nerves pass through this layer to reach the papillary layer
Reticular layer
APPENDAGES OF THE SKIN
- Nails
- Hair
- Sebaceous glands
- Sweat or sudoriferous glands
- Ceruminous glands
clear layer has thickened to form a hard protective covering
Nail
stratum lucidum
Nail
proximal part that is covered by a fold of skin, and hidden from view
Nail root
exposed part, with its free edge projecting over the tip of the digit
Body of the nail
is the white part of the nail body, shaped like a half-moon close to the nail root
Lunula
outer horny layer of epidermis at the base of the nail that tends to grow out over the nail body
Eponychium
modification of the epidermis
Hair
a small canal opening upon the skin surface and extending down the dermis or even the subcutaneous tissue
Hair follicle
part below the skin level lying in a hair follicle
Root of a hair
inner enlarged end of each hair root
The bulb
small secreting glands that lie beside and open into hair follicles
Sebaceous gland
Sebaceous gland secretes oily substance called _____
sebum
lubricates hair and skin
Sebaceous gland
simple tubelike glands consisting of a single canal or duct, and a coiled secreting part
Sweat or Sudoriferous glands
secrete watery solution containing sodium chloride and minute quantities of other waste products including urea
Sweat or Sudoriferous glands
modified sweat glands located in the external ear that secrete wax into the external acoustic (auditory meatus)
Ceruminous glands
consists of areolar (loose connective tissue) forms a layer between the skin and such structures as muscles, bones, or organs that lie deep to the skin
Subcutaneous tissue
FUNCTIONS OF THE SKINS
- Protective covering to prevent injury or destruction of underlying tissues
- Excretes water and some waste products
- Helps regulate body temperature
- Contains sensory receptors of sensory nerves, and transmit to the brain, sensations of the external environment
glands are organized units of epithelial cells that extract raw materials from capillaries and intercellular spaces and manufacture new substances or secretions
Secreting glands
secretes substance into the bloodstream (hormones)
Endocrine glands
secretes substances onto a surface, usually through a duct (enzyme)
Exocrine glands
CLASSIFICATION OF EXOCRINE GLANDS
- Simple tubular gland
- Branched tubular gland
- Simple saccular or alveolar gland
- Branched saccular or alveolar gland
- Combined tubualveolar gland
