Integumentary Flashcards
The scientific study and medical treatment of the integumentary system
Dermatology
Accessory organs of the skin are
Hairs nails oil and sweat glands
Functions of the skin
Protection, temperature, excretion, vitamin d synthesis, Sensory reception, storage
The body’s largest and heaviest organ
Skin
Two layers of skin are
Epidermis and dermis
Hypodermis
Below not part of skin
Thick skin is found
Palms of hand and sole of feet
Thin skin
Covers rest of the body (hair follicles, sebaceous glands and sweat glands
Epidermis is composed of
Dry keritanized stratified squamous epithelium
Five layers of epidermis and there functions
Stratum basale
Function- divide, mitosis of stem cells.
Stratum spinousum
Function- strength and flexibility
Stratum granulosum
Function strength and flexibility contains coarse dark staining kerathoyalin granules
Stratum lucidum
Stratum corneum
Function- protects underlying skin from infection dehydration h2o poss chemical and physical stress
3-5 layers of flattened, translucent dead cells found only in thick skin palms and soles
Accounts for 15% of body weight
skin
A pigment produced by melanocytes
Melanin
A red pigment found in hemoglobin of red blood cells
Heme
Epithelial tissue pinches off to form ductless endocrine glands found with in connective tissue
Endocrine glands
Hypodermic sub q injections are administered here because this layer is highly vascular and drugs are absorbed quickly
Hypodermis
Composed of a regular dense connective tissue you containing fibroblast bundles of collagen and of course elastic fibers
Reticular layer of dermis
Composed of areas ct capillary loops meissner corpuscles and free nerve endings
Papillary layer of dermis
Consists of 3-5 layers of flattened keratinocytes undergoing apoptosis
Stratum granulosum
Consists of 3-5 layers of flattened translucent dead cells found only in thick skin palms and soles
Stratum lucidum
Consists of 15-30 layers of dead, flattened cells filled with keratin ; flake off as tiny specs of dander every two weeks
Stratum corneum
Single layer of cuboidal to low columnar stem cells and keratinocytes that lie on basement membrane
Stratum basale
Consists of 8-10 layers of kerantinocytes held together by desmosomes; some maintain capacity to divide
Stratum spinosum
These glands are large And active at puberty
Apocrine (odiferous) glands
Simple tubular glands found over entire body
Eccrine (merocrine ) sweat glands
Found at base of hair follicle, secrete sebum into hair follicle
Oil (sebaceous) glands
Visible portion the projects from skin
Hair shaft
Dead keratinized threads of epidermal cells cemented together
Hair(pili)
Visible portion the projects from skin
Hair shaft
Below skin surface penetrates dermis and hyper dermis
Hair root
Sensory nerve endings (receptors) around hair follicle detect movement ( light touch)
Hair root plexuses
Smooth muscle attached half way down hair follicle
Arrector pili
What do eyelashes do
Screen out foreign agents
What do eyebrows do
Preevent sweat from dripping into eyes
Trap dust and other large particles
Nostrils
Prevent heat loss
Scalp
Visible portion flattened keratinized dead cellsof stratum corneum filled with harder type of keratin; pink due to underlying capillaries
Nail Body
Cemented plates of hard keratinized dead epidermal cells
Nails
Extends past finger appears white because no underlying capillaries
Free edge
Lies within nail fold
Nail root
Semilunar portion is white due to thickened stratum basale below
Lunula
Thin layer of stratum corneum at base of nail
Eponychium (cuticle)
Beneath free edge thickened region of stratum corneum that secures nail to fingertip
Hyponychium (nail bed)
Where new growth arises rate of nail growth is influenced by persons age health nutritional status and season
Nail matrix
Respond to pain and temperature
Free nerve endings
Receptors for light touch in papillary
Meissner a corpuscles
Receptors for sustained (deep) pressure
Pacinian corpuscles
specialized epithelial cells in stratum basale, in conjunction with nerve endings receptors for touch.
Merkel discs
Protect tips of fingers and toes and allow one to manipulate objects
Nails
What are the 3 layers of hair shaft and root
medulla- 2-3 rows of irregular shapes cells that contain soft keratin and melanin
Cortex- bulk of shaft; elongated cells contain hard keratin and melanin
Cuticle- single layer of thin, flat cells contain hard keratin and overlay to form shingles
