Chapter 5 Flashcards
The integumentary system
-two major components
- The skin : cutaneous structures
2. Accessory structures
The skin
- how many layers
- name the layers
- 3
- Epidermis
- Dermis
- Hypodermis
- Epidermis
Epidermis
- type of tissue
- 2 types of cells
- layers (definition)
- Stratified squamous epithelium
- Keratinocytes and melanocytes
- Thick vs thin (refers to relative thickness of the epidermi
Keratinocytes
Make up most of the skin
Melanocytes
Provides pigment that protects
5 layers of the epidermis
- Stratum corneum
- Stratum lucidum
- Stratum granulosum
- Stratum spinosum
- Stratum germinativum
Stratum corneum
- how many rows
- are the cells dead or alive
- what occurs
- location
- function
- 15 - 13 rows
- dead
- keratinization or cornification (filled with keratin intermediate filaments)
- (top) superficial layer
- forms protective, waterproof covering
Stratum lucidum
- where is it found
- what color
- what do the cells look like
- thick skin only
- clear layer
- keratinocytes are flat, packed together, and filled with keratin
Stratum granulosm
- what color
- how many rows
- type of cell
- waterproofing proteins
- what happens here
- Darkly stained region
- 3-5 rows
- keratinocytes that have stopped dividing
- keratohyalin and keratin
- keratinocytes begin to die and dehydrate
Stratum spinosum
- how many rows
- what do the cells look like
- what are the cells held together by
- what type of cells are present
- 8-10 rows
- spiny shaped keratinocytes
- desmosomes
- Langerhans cells
Langerhans cells
-function
- immune response
- attack microorganisms that enter superficial layers
Stratum germinativum or Basale
- how many layers
- what is it attached to
- what does it separate
- what does it form
- can the cells divide
- what types of cells are present
- single layer
- basement membrane
- epidermis from dermis
- forms epidermal ridges that extend into dermis
- yes
- melanocytes
Dermis
- location
- type of tissues present
- what does it contain
- 2 layers
- between epidermis and hypodermis
- connective tissue
- blood vessels and accessory structures
1. Papillary layer
2. Reticular layer
Papillary layer
- what is it made of
- contains 3 things
- what does it look like on skin
- areolar connective tissue
- capillaries, sensory nerves and fingerlike projections called papillae
- gives ridge-like pattern (fingerprints)
Reticular layer
- what is it composed of
- contains 3 things
- what are the fiber bundles responsible for
- dense irregular CT
- sensory receptors, blood vessels and hair follicles
- “lines of cleavage”
Hypodermis
composed of areolar CT and adipose tissue
how are collagen and elastic fibers arranged and how are they oriented ?
- in parallel bundles
- oriented to resist forces applied to skin during movement
significance of lines of cleavage
-2 things
- A cut parallel to a line of cleavage will heal with a little scarring
- A cut across a line of cleavage creates scarring because wound will remain open
What causes stretch marks?
- when elastic properties of skin are exceeded
- damage to dermis occurs and prevents it from returning to its original size
Accessory structures
-3
- Hair
- Glands
- Nails
Hair
- location
- 2 types
- almost everywhere
1. Vellus hairs
2. Terminal Hairs
Vellus hair
fine hair located over much of the body surface
-some will become terminal hairs at puberty
terminal hair
heavy, deeply pigmented and sometimes curly
Hair follicle
-3 functions
- produces hair
- can alter structure of hair
- invagination of epidermis
7 hair and hair follicle structures
- Hair shaft
- sebaceous gland
- arrector pili muscle
- connective tissue sheath
- hair papilla
- hair bulb
- hair root
arrector pili muscle
contracts to pull hair upwards
connective tissue sheath
wraps each hair follicle
hair papilla
contains capillaries and nerves
hair bulb
beginning of hair root
hair root
contains germative layers of hair follicle
medulla of hair
core of hair
cuticle of hair
surface of the hair
hair color
- what determines it
- ranges
- what does white/gray hair mean
- determined by pigment produced by the melanocytes at the papilla
- dark brown, yellow brown or red
- lack of pigment production and presence of hair bubbles in medulla
Hair growth and replacement
- how much does the hair grow per day
- what do hair root cells do
- what happens in replacement
- ~0.33 mm
- absorb and incorporate nutrients into growing hair
- new hair will push out the old one
club hair
hair in an in-active follicle
3 functions of hair
- insulation
- protection from UV light (scalp)
- prevents entry of foreign particles
Glands
-2 types
- Sebaceous
2. Sudoriferous
Sudoriferous gland
- definition
- what do they produce
- holocrine glands that discharge oily lipid secretions into hair
- sebum
sebum
-2 functions
- inhibits growth of bacteria
2. lubricates and protects hair shaft
Sudoriferous gland
- defintion
- 2 types
- sweat glands
1. merocrine sweat glands
2. apocrine
merocrine sweat glands
- where do they secrete to
- what does it produce
- 2 functions
- what does it excrete
- directly to surface of skin
- watery perspiration (“sensible perspiration”)
- cooling surface of skin and protection from microorganisms
- water and electrolytes
apocrine sweat glands
- 3 locations
- where does it secrete to
- what does it look like
- when does this start happening
- armpits, nipples, pubic region
- into hair follicles
- sticky, cloudy, odorous secretion
- puberty
Nails
-function
protect exposed dorsal surface of tips of fingers and toes
Lunula
-area on nail where blood vessels are not seen
Nail fold
Boundaries for nail body
Eponychium
Area of stratum corneum on nail
Hyponychium
Area of thickened stratum corneum on nail
Nail root
Where nail production occurs
Integumentary system
-function
provides protection from dehydration, environmental stressors and impacts
Nervous system
Receptors in deep epidermis and dermis provide sensations of touch, pressure, vibration, temperature and pain
Cardiovascular system
can stimulate localized changes in blood flow
Lymphoid system
provides physical barriers that prevent entry of pathogens
Respiratory system
Guards nasal cavity
Assists in excretion of water and solutes can also limit fluid loss through the skin
Urinary system
Reproductive system
Covers external genitalia and provides sensations that stimulate sexual behaviors
