Integumentary System Flashcards
what are the characteristics of the integumentary system
- multiple layers
- maintains homeostasis
- provides a protective covering
- contains immune system cells
- has sensory receptors
- retards water loss by diffusion
- synthesizes chemicals
- excretes small amounts of water
what are the layers of skin in the integumentary system
- epidermis-outer layer
- dermis-inner layer
- subcutaneous layer
what are characteristics of the epidermis
- made of stratified squamous
- lacks blood vessels
- contains large amounts of keratin
- thickness varies by location
- contains melanocytes
the deepest layer of epidermis where rapid cell division takes place is called
stratum basale
superficial layer of epidermis where cell loss happens is called
stratum corneum
what is the purpose of keratin
to toughen and waterproof cells
where is keratin found
in the very outer layers of the stratified squamous epithelium or the stratum corneum
what is a characteristic of healthy skin
cell production equals cell loss
what is melanin
- protein with a very dark color
- produced by melanocytes found along basement membrane
- absorbs light
- functions to prevent damage, mostly from UV light
what are characteristics of the dermis
- binds epidermis to underlying tissues
- composed of irregular dense CT
- contains muscle fibers
what structures are located in the dermis
- nerve cell receptors
- blood vessels
- hair follicles
- glands
characteristics of subcutaneous layer
- also called hypodermis
- not actually apart of skin
- composed of loose & adipose CT
- contains major blood vessels
what are functions of the subcutaneous layer
- insulate the body
2. connect skin to underlying structures
what structures are found in the skin
- hair follicles
- nails
- sebaceous glands
- sweat glands
what epidermal cell forms hair follicles
stratified squamous
what type of depression does a hair follicle make
tube-like
what are the parts of a hair follicle
- hair root
2. hair shaft
what is the composition of hair
- tightly packed dead epidermal cells
2. melanin that imparts color
what are the associated structures of hair follicles
- Arrector pili muscle (smooth muscle)
2. Sebaceous glands
what is the function of nails
protects the most distal phalanges which can be easily damaged
what are the components of the nail
- nail plate
- nail bed
- lunula
what is the function of the nail plate
covers underlying skin
what is the nail bed
specialized epithelial cells that are continuous with the epidermis of the skin
what is the lunula
most active growing region of the nail, where cells divide and become keratinized
what are the characteristics of sebaceous glands
- usually associated with hair follicle
- is a holocrine gland
- secretes sebum
- are absent on palms & soles
what is a holocrine gland
a secretory gland where cells of the gland ruptures to release secretion
what is sebum
an oily secretion and cellular debris that coats hair
what are the types of sweat glands
- Eccrine
- Apocrine
- Ceruminous
what are the characteristics of the eccrine gland
- located in the dermis
- is the most common gland
- ducts open to surface
- helps with temperature regulation
what are the characteristics of the apocrine gland
- located in the dermis and subcutaneous layer
- opens to hair follicle
- found on: axilla (armpit), groin, face
- believed to secrete pheromones
what are the characteristics of the ceruminous gland
- found in the ear
- opens into ear canal
- secretion combines with sebum from a hair follicle to form a “waxy” secretion for protection
what are the mechanisms of sweat for body temperature regulation
- body temperature exceeds set point
- sweat forms & is evaporated into air
- evaporation of the sweat cools the skin
- cooled blood circulates back into the main circulation to maintain an acceptable internal temperature
what is the major method of heat loss
evaporation of sweat
what problems can be caused by water & electrolyte loss
- muscle cramps
- cardiac arrhythmias
- neuron dysfunction
examples of neuron dysfunction caused by water & electrolyte loss
- loss of control to organs/structures
2. altered mental status
what are factors that affect skin color
- genetics
- environmental
- physiological
what are environmental factors that affect skin color
- sunlight
- UV rays
- X-rays
how do environmental factors affect skin color
- darkening of existing melanin
2. stimulation of melanocytes to produce more melanin
how does physiological factors affect skin color
- dilation of dermal blood vessels
- constriction of dermal blood vessels
- accumulation of carotene
- Jaundice
first degree burns affects what
epidermis (superficial, partial-thickness)
second degree burns affects what
epidermis & dermis (deep, partial-thickness)
third degree burns affects what
epidermis, dermis, & subcutaneous (full-thickness)
what are the types of skin cancer
- Basal Cell Carcinomas~78%
- Squamous Cell Carcinomas~20%
- Malignant Melanomas~2%
characteristics of basal cell carcinomas
- arise from stratum basale
- rarely metastasizes
characteristics of squamous cell carcinomas
- arise from squamous cells of epidermis
- has a variable rate of metastasis
characteristics of malignant melanomas
- arise from melanocytes
- metastasizes quickly
- has high rate of mortality
what are genetic factors that affect skin color
- varying amount of melanin in cells
- varying size of melanin granules
- lack of melanin (albinism)
what are the four layers of the epidermis
- Stratum Basale
- Stratum Spinosum
- Stratum Granulosum
- Stratum Corneum
what is the possible 5th layer of epidermis found in thick skin
• Stratum Lucidum
what are the sensory receptors found in the dermis
- Ruffini
- Krause corpuscle
- Pacinian corpuscle
- Meissner corpuscle
- Free nerve endings
