Integumentary Flashcards
Epidermis
- superficial region
- is avascular and made of epithelial tissue (duh)
5 parts of integumentary system
- skin
- nails
- hair
- sweat glands
- sebaceous glands
Dermis
underlies epidermis
- fibrous connective tissue and vascular
Hypodermis (superficial fascia)
- deep to skin
- not part of skin but shares function
- adipose tissue
-anchors skin to underlying structure
Function of Skin (5)
protection of underlying tissues and organs
- excretion of salts and water
- maintenance of body temperature
- production of melanin
- detection of pressure and pain
Keratin
Protein produced by skin for protection, has yellow pigment
Vitamin D
synthesis of Vitamin D
Lipids
Lipids are stored in skin
What is Epidermis made of? *3 cells
- Keratinocytes
- Melanocytes
- Dendritic (Langerhans) cells
Keratinocytes (function and traits)
- produce the fiber keratin
- connected by desmosomes
- very regenerative
Melanocytes
Produce pigment melanin, which is packaged into melanosomes
Dendritic (Langerhans) cells
Star-shaped macrophages that patrol deep epidermis and activate immune system
Tactile (Merkell) Cells
Sensory receptors that sense touch
Melanosomes
are transferred to keratinocytes, where they protect nucleus from UV damage
How many layers does the epidermis have?
- 4 or 5 (when thicker skin is needed for protection)
What are the five layers of the skin?
Stratum basale
Stratum spinosum
Stratum granulosum
Stratum lucidum
Stratum corneum
Which layer is only in thick skin?
Stratum lucidum
Stratum Basale
- deepest layer
- Consists of a single row of stem cells that actively divide (mitotic)
- also has melanocytes
Stratum Spinosum (Function)
- contain desmosomes
- Allows resistance tension and pulling
- growth
Stratum granulosum
- flat layer
- Cell appearance changes -Cells flatten, nuclei and organelles disintegrate
- Keratinization begins
here
Prickle Cells
Keratinocytes in this Stratum Spinosum appear spikey, so they are called prickle cells
Stratum Lucidium
- only in thick skin and stains clear
- is superficial
Stratum Corneum
- Skin cells here are dead but provide protection and prevent water loss
Tissue type of layers in dermis
- connective tissue that hold things in place
Papillary Layer (tissue and function)
Superficial layer of areolar connective tissue consisting of loose, interlacing collagen and elastic fibers and blood vessels
- contains dermal papillae
Dermal papillae
superficial region of dermis that sends fingerlike projections up into epidermis
Function of Dermal Papillae
- ## surface area
Dermal Ridges
Collectively ridges are called friction ridges
Function of Friction Ridges
- Enhance gripping ability
- Contribute to sense of touch
- Sweat pores in ridges leave unique fingerprint pattern
Reticular Layer
- Consists of coarse, dense fibrous connective tissue
- holds things in place
Cleavage Lines
-in reticular layer
-caused by many collagen fibers running parallel to skin surface
-Externally invisible
- imp to surgeons because incisions parallel to cleavage lines heal more readily
Flexure Lines
- Dermis is tightly secured to deeper structures
- Skin’s inability to slide easily for joint movement causes deep creases
- Visible on hands, wrists, fingers, soles, toes
Medical Name for Stretch Marks
Striae
Three Pigments
- Melanin
- Carotene
Freckle/Mole
accumulation of melanin
Carotene
- yellow to orange pigment
- accumulates in stratum corneum
Hemogoblin
- pinkish hue of skin
- lighter skin allows pink to show
Cyanosis
- blue
- lower oxygenation of hemoglobin
Pallor
-pale color
- fear, low bp, anemia
Erythema
- fever
- hypertension
- red color
Jaundice
- yellow cast because of liver disorders
Hair
dead hard keratinized cells
4 functions of Hair
-Warn of insects on skin
-Hair on head guards against physical trauma
-Protect from heat loss
-Shield skin from sunlight
Hard Kertatin vs Soft Keratin
Hard keratin is tougher and more durable, and cells do not flake off
Shaft
area that extends above scalp, where keratinization is complete
Root
area within scalp, where keratinization is still going on
3 parts of hair shaft
- Medulla
- Cortex
- Cuticle
Medulla
central core of large cells and has strength
Cortex
several layers of flattened cells surrounding medulla
Cuticle
gives hair its properties ; outer layer consisting of overlapping layers of single cells
What pigment does red hair have?
Red hair has additional pheomelanin pigment
Hair Bulb
expanded area at deep end of follicle ; the only part with DNA
Hair Follicle Receptors
sensory nerve endings that wrap around bulb
What is the sheath made of? Where is it derived from?
peripheral connective tissue sheath
- also called fibrous sheath
- dermis
Hair Matrix
actively dividing area of bulb that produces hair cells
Arrector Pili
small band of smooth muscle attached to follicle ; these are responsible for goose bumps
Human Hair Growth Cycle Stages
- Active Anagen
- Catagen
- Telogen
- Early Anagen
Active Anagen
active phase of hair growth
Catagen
- not enough blood flow to grow hair but enough to sustain hair follicles
Telogen
rest stage
- normal to lose 100 hairs a day
Early Anagen
the active growth phase of hair follicles
Alopecia
hair thinning in both sexes after 40
Telogen Effluvium
abrupt hair thinning caused by an abundance of hair follicles entering resting phase at same time
Causes of Telogen Effluvium
Can be due to stress-induced factors such as: hormonal changes, surgery, severe emotional trauma, or crash dieting
Hirsutism
excessive hairiness
What are nails made out of?
Hard Keratin
Function of Nail
Protection ; human nails have lost a lot of their function
Eponychium (cuticle)
nail fold that projects onto surface of nail body
Hyponychium
area under free edge of plate that accumulates dirt
Lunule
white moon shape ; thickened nail matrix
When will your nail not grow back?
if you damage the nail matrix and root
Nail Matrix
thickened portion of bed responsible for nail growth
What do yellow tinged nails indicate?
respiratory or thyroid gland disorer
Thickened yellow nails indicate?
fungal infection
Koilonchya *spoon nails
an outward concavity of nail may signal iron deficiency or early signs of a heart disease
Beau’s lines
horizontal lines across nails may indicate severe illnesses such as uncontrolled diabetes, heart attack or cancer chemotherapy, or that you were stressed
Sudoriferous glands
sweat glands that are present in all skin surfaces except nipples and parts of external genitalia
Two main types of glands
Eccrine and Appocrine
Appocrine glands
- Bacteria break down sweat, leading to body odor
- do not function until puberty
- produces fatty oily sweat
Sebaceous Gland
- oily secretion found in hair follicles
- produces waterproof barrier
Eccrine Sweat Glands
- watery sweat glands with little bit of salt
What are the modified apocrine glands
Ceruminous Glands
Mammary Glands
Ceruminous Glands
lining of external ear canal; secrete cerumen (earwax)
Mammary Glands
secrete milk
insensible perspiration
Under normal, resting body temperature, sweat glands produce about 500 ml/day of unnoticeable sweat
Sensible perspiration
If body temperature rises, dilation of dermal vessels can increase sweat gland activity to produce 12 L (3 gallons) of noticeable sweat ; designed to cool body
What does a cold external environment do to vessels?
- Dermal blood vessels constrict
2.Skin temperature drops to slow passive heat loss
Keloid
Scar Tissue
Fibroblast help wounds heal by
producing fibers (like collagen), that help close the wound
Morphology
how to describe what you see
What 6 things are identified by morphology
Palpability (indicated by shadow)
Color
Shape
Texture
Size
Location
Macule
it is flat spot in the skin ; you cannot feel it
Patch
it’s flat and larger than 1 cm
Papules
- raised lesions less than 1 cm
- caused by a proliferation of cells in epidermis or superficial dermis
Plaque
- greater than 1 cm
- caused by a proliferation of cells in epidermis or superficial dermis
- cast a shadow
Nodules
- small knot
- caused by a proliferation of cells into the mid-deep dermis
Vesicle
are fluid-filled papules (small blisters)
Bulla
Vesicle larger than 1 cm
Pus
made up of leukocytes and a thin fluid called liquor puris
Erosion
- loss of part or all of the epidermis
- can occur after a vesicle forms and the top peels off
- weep and become crusted
- do not heal with scars
Ulcers
complete loss of the epidermis in addition to part of the dermis
- heal with scars
Cyst
e round lumps, often filled with fluid or pus
Comedo
infected oil gland (blackhead)
Wheal
inflamataory raised area
Abscess
pocket of pus
Furnucles
A painful, pus-filled bump under the skin caused by infected, inflamed hair follicles.
Nevus
fancy birthmark
Cutaneous Sensations
Sensations based on the stimulation of receptors in the skin
Example of Cutaneous Sensations
Pressure, vibration, healing and cooling
Meisnener Corpuscle
Light Touch, Flutter, Movement
Pacinian
Vibration ; look like onions (ewwwwwwwwwwww)
Ruffini
Stretch
Merkel
Touch and pressure
Nerve Ending
pain and temperature
Hair Follicle
nerves wrap around hair follicle
Propioception
body sense - balancing the body
Kinesthesis
sense of position and movement
Dermatomes
one nerve ending
