Skin Unit Flashcards
integumentary system
skin and its components (oil and sweat glands, hair and finger/toenails)
The skin comprises ____ to _____ of adult weight and covers area of _____ to _____ square meters.
15% - 20% of adult body weight
covers an area of 1.5-2.0 m²/18ft²
largest and heaviest organ of the human body
skin
Skin is challenged by….
radiation, pollution, injury, infection, dangerous chemicals and immune system attack
Doctors can learn ??? from our skin
clues about our general health
nutritional status, and disorders present such as liver cancer, anemia, diabetes and heart failure
The skin organ renews itself every ______ days
30 – 45 days
How is skin protection/barrier:
tothings permeating or losing things:
- microorganisms
- fluid loss/gain
- mechanical(friction contact, ex.clothes)
- chemical irritants
How does skin assist in temperature balance?
Temperature Balance Via fluid releases from sudoriferous (sweat) glands and reflexes of skin blood vessels
Skin is excretion medium for:
Fatty substances(oils)
H20
salts
vitamin residue
Uric acid
ammonia
How is skin involved in production of Vitamin D
via 7- dehydrocholesterol + sun exposure
liver and the kidneys as well will play a role in completion of this vitamin production process
Scientists starting to look at VitD more as a horemone – calcium absorption, and other roles
3 layers that make “skin
epidermis
dermis
hypodermis/ subcutaneous layer
epidermis structure
loose, flat, dry cells, condensed
dermis
loose and tough connective tissue, lots of organs (blood vessels, pain receptors, nerve receptors, tubular growths – hair follicles, thick to hold all stuff
subcutaneous or hypodermis
- made of adipose or fat tissue with blood vessels
- not considered part of the skin but helps to bind the skin proper to underlying muscle, bone organs and
- barrier to heat loss. It also stores lipid molecules which can be used to meet the nutrition and metabolic needs of the body
- aedopous tissue and blood vessels; binds to other tissues, keeps warm
The “true skin” is composed of
two kinds of tissue,the epidermis (flat dry cells) and the underlying dermis (loose and tough connective tissue)
The Epidermis is made out of 5 layers
Top-Down
- Stratum corneum
- Stratum lucidum
- Stratum granulosum
- Stratum spinosum
- Stratum basale
Stratum corneum
1- uppermost layer
25 to 30 layers of dead heavily keratinized, nonliving scales, which become increasingly flattened as they approach the skin surface
slough off (desquamation)
new epidermis is produced every 30 -45 days (30 days up to 2 months)
Stratum lucidum
- 2nd layer from surface
- clear, translucent layer of flattened, non-nucleated (no organelles), dead or dying cells
- four to seven cells deep
Stratum granulosum
- 3rd layer from surface
- three to five cell layers filled with keratohyalin granules,(precursors of keratin)
- Keratin is a a tough, resilient protein that waterproofs/protects exposed skin surfaces
Stratum spinosum
4th layer
above stratum basale/ germinativum
cells with sharp pointed pieces coming off the cell to hold each other in place
5-Stratum basale (germinativum)
- at the very bottom
- “basale” means they are constantly going through cell cycling mitosis processing
- highly mitotic and produces continuous cells that move upward to the superior layers
- Melanocytes located here - produce a pigment called melanin that helps to color the skin/protect it from sun (genes determine melanin tones)
Basic Structure - Dermis
Layer under 5 layers of epidermis
Function: holds up epidermis and binds the epidermis to other tissues
thickest/busiest layer of the skin
primarily connective tissue, particularly collagen and elastic fibers in a gel – like substance
thickest and structurally busy layer of the skin
Contains: nerve fibers, sensory fibers/receptors, nail roots, erector pili muscles(goosebumps), hair follicles, sebaceous glands (oil) and sudoriferous glands (sweat glands)
blood vessels in dermis carry nutrients to upper layers of the skin and help regulate temperature
Damage and aging does what to skin?
dermis: (makes fewer cells) of these fibers causes wrinkling – loses taughtness which causes epidermis wrinkles
hypodermis:
Thins as we get older, this linked to wrinkling too, also cause sensitivity to temperature changes
How dermis helps regulate temperature
blood vessels in dermis carry nutrients to upper layers of the skin and help regulate temperature
Hypodermis layer of skin
- Not considered a “true skin” layer but still very important
- Made of adipose tissue, has lots of blood vessels in it and works to insulate body from heat loss
- Thins as we get older, this linked to wrinkling too and thus will also cause us to be extra sensitive to temperature changes
hypodermis
Fat suluble injections are put into what layer of skin?
Sebaceous Glands
- oil glands
- release sebum- a mixture of oils, waxes, and cell debris
- ducts hold then released (genes, timetables affect oil production)
- Serves as a skin softener - emoillent
- Serves as a film on the skin that blocks excessive water loss.
- Serves as a film on the skin that kills bacteria, bacteria hate it
Ceruminous Glands
release earwax, which traps debris entering the ear canal, “cerum” is clinical name for earwax
Sudoriferous Glands
- release sweat, a liquid mostly made of water, salt, vitamin C, fat molecules, proteins and metabolic wastes (uric acid, ammonia)
- acidic pH between 4 -6.
- Body has 2.5+ million sudoriferous glands antibacterial
- serves as a liquid coating that absorbs heat and evaporates as an aerosol leaving a cooling sensation across the skin
Mammary Glands (Modified sweat glands)
- in breast tissue and in women are sensitive to estrogen (increases gland size during pregnancy)
- prolactin (stimulates glands to pull together protein, vitD, phosphorous, and oxytocin hormones bind to muscles and mammary glands to squeeze out the milk out of the breast; which enhance their sizes during pregnancy and promote milk production and secretion after birth (Lactation)
sweat
- Sweat is antibacterial
- liquid coating that absorbs heat and evaporates as an aerosol leaving a cooling sensation across the skin
- Sudoriferous Glands (Sweat)
- release sweat, a liquid mostly made of water, salt, vitamin C, fat molecules, proteins and metabolic wastes (uric acid, ammonia)
- acidic pH between 4 -6.
- Body has 2.5+ million sudoriferous glands.
portion of hair above the skin
portion of hair in the hair follicle
shaft - above the skin/scalp surface
hair root- the portion in the hair follicle
living cells of hair are located
in and near the bulb
dermal papilla
vascular connective tissue near bulb of hair
Root and shaft of hair = 3 three layers of epithelium:
Cuticle: is the outer layer of scaly, dead cells
Cortex: the middle keratinized layer, forms the major portion of the shaft, contains pigment melanin, amount determines hair color
Medulla: thin vertical axis also known as the central axis, consists of two-three layers of cells, poorly developed and frequently absent, especially in blond hair
hair is ____% dead
95%
_______ and ______ glands release products into hair shaft to be released through epidermis
Sweat and oil glands
Anagen, catagen and telogen
Hair has a growth cycle that includes three stages:
Anagen stage varies from ____ to ____ years of growth
2-6 years of growth; people genetically programmed to a series of years hair growth pattern
when dead skin flakes off it is called ________ and the stuff that comes off is referred to as ______
exfoliating
dander
dandruff
clumps of dander stuck together by sebum (oil)
“prune fingers and toes” after pool
result of stratum corneum absorbing water and swelling but deeper layers do not so it causes the wrinkle look
Dermis layers and terms
wavy boundry between epidermis and dermis
- dermal papillae - upward waves, fingerlike extensions
- epidermal ridges are downward waves between papillae
papillary layer of dermis is what tissue?
thin zone of areolar tissue especially rich in small blood vessels
reticular layer of dermis
deeper and much thicker than papillary layer
dense connective tissue
blisters caused by
- damage of dermal blood vessels in dermis from friction or burns
- serous fluid seeps out of blood vessels andaccumulate as a blister
- separating epidermis from dermis until the fluid is reabsorbed or expelled
stretch marks are the result of
collagen in reticular layer of the dermis tearing
Baldness
a progressive deterioration of hair follicles
Short/long-term or permanent factors related to baldness
- sex influenced genetic traits expressed when testosterone levels are high stress (high mitotic cells slow down)
- fungal infection (block hair growth)
- autoimmune disease (lupis, MS)
- drug/alcohol abuse (damage/slow cell base)
- chemotherapy (kills normal cells too)
- chemical and mechanical injury (hair style with weight) to the scalp
No hair zones -
palms and soles, front/side surfaces of fingers and toes and the lips, nipples and parts of the genitals
About ________ hairs in a man’s 6” beard and about _______ to _______ hairs on the average person’s scalp.
About 30,000 hairs in a man’s 6” beard and about 100,000 – 300,000 hairs on the average person’s scalp.
arrector pili muscles
thin bands of muscle associated with hair follicles. Their contraction causes the hair to “stand on end” (skin/hair wall force field) to block cold air/skin contact, and as we also know, the
closing of skin pores (goose pimpling) and shivering and body heat production on a cold day. This contraction also
causes the secretion of oil from nearby sebaceous glands.
Hair texture is related to
the cross-sectional shape of the hair
straight hair is round
wavy hair is oval
tightly curled hair is relatively flat
Hair color
- is due to melanin pigment granules in the cortex
- black or brown hair is rich in darker pigmented eumelanin
- Red hair has a slight amount of eumelanin, higher pheomelanin
- Blond hair has some pheomelanin but very little eumelanin
- Gray and white hair from an absence of melanins in the cortex of hair and air in the medulla of the hair
vellus, terminal, and lanugo hair
Most hairs found on the body are vellus hairs, tiny colorless hairs. (can’t see generally)
Terminal hairs, (hairs you can see) which are coarse and easy to see are found confined to the scalp, eyebrows and eyelashes and with the onset of puberty, they appear on the armpit and pubic regions of the body and on the faces of men
Lanugo is hair that is present only prenatally, when baby born
Functions of hair include:
- thermal insulation
- protection from the sun and foreign objects
- sensation, facial expression (eyebrows move)
- signaling of sexual maturity
- regulating the dispersal of pheromones (trap pheromones, horemones that play a role in attraction)
Nails
root, eponychium, lunula, nail plate, hyponychium
- Fingernails and toenails are mostly dead/nonliving protective plates that arise from down growths of the epidermis into the dermis. These structures are only found in humans and primates
- Root is covered with skin – that is the living part, always making cells
- Eponychium (cuticle) Cuticle skin covers the root
- Lunula – the “moon” between the living and the dead (cells that are dying)
- Nail plate/body – dead cells
- Hyponychium – tissue growth beyond the plate under the nail (at tip)
Fingertips and nails in medical diagnosis:
- Swollen or clubbed fingertips may indicate long – term oxygen deficiency
- Dietary deficiencies, like that of iron, can be reflected in nails that become flat or concave
- Biotin deficiency may result in nails that are thin and easy to break (Vit B. deficiency)
All people have same # of melanocytes, _____ determines skin coloring
DNA determines coloring
Melanocytes and other factors of skin color
- (pheomelanin) responsible for reddish and yellow, lighter, beige like coloring (eumelanin) brownish and black tones
- hemoglobin, the red pigment of blood, reddish to pinkish hues to the skin as (artery based) O2 rich blood flows and shows through dermal blood vessels bluish tinge (veins) is offered from deoxygenated venous blood flow through the skin.
- Carotene, an orange - yellow pigment acquired from ingested foods such as egg yolks, carrots, squash and sweet potatoes can become concentrated in the upper layers of the epidermis and in the hypodermis/subcutaneous layer
- Weather and environmental factors may influence skin color too, such as consistent exposure to sunlight or the lack thereof and
- deposits over time from particulate matter and chemicals in work environments (coal mines/chemical and industrial plants, asphalt/tar application work environments-may have darker tint to the skin, hand to right)
Abnormal skin colors of medical diagnostic value
cyanosis
erythemia
pallor
Cyanosis: is the blueness of the skin resulting from a deficiency of oxygen in the circulating blood. (Seen in choking, drowning, cardiac arrest and various lung diseases)
Erythema is abnormal redness of the skin which can present during exercise, in hot weather, sunburn, during allergic reaction, anger or embarrassment
Pallor is (lost skin color) a pale or ashen color that occurs when there is little blood flow through the skin and the white color of the dermal collagen shows through. (Seen in times of emotional distress, low blood pressure, circulatory shock, cold temperatures or severe anemia) Anemia either too few red blood cells or they aren’t working correctly
Albinism
- genetic lack of melanin that usually results in milky white hair and skin and blue-gray eyes
- lack in the enzyme tyrosinase which is needed to turn the amino acid tyrosine into melanin
- Can get sun poisoning – like allergic reaction to sun
Jaundice
- is the yellowing of the skin and whites of the eyeballs (sclera)
- resulting from high levels of a pigment, bilirubin, in the bloodstream. (Bilirubin can accumulate enough to discolor the skin as a result of rapid erythrocyte destruction, and when diseases such as cancer, hepatitis and cirrhosis hamper liver function or in newborns whose livers aren’t developed enough to dispose of bilirubin efficiently
Basal cell
Stratum basal layer
Most common but “least dangerous”
Doesn’t spread
Shiny bump like a pearl, gets bigger over time, may shrink over time
Eventually a depression within it
Patches of discolored skin, caused by tumors of blood vessels
Hemangiomas or birthmarks
Gorbachov – port wine hemangioma on head
Flexion lines
Creases or lines on the skin on skin
– caused by flexing the skin
Tinea Pedia is also known as
- “athlete’s feet”
- Fungal infection of the feet
- Infection: usually sweating a lot with lots of friction; microabrasions caused in skin by function, fungus gets in the cracks and you get the painful lesion (breaking of normal structure)
- Treatment – cleaning, drying, creams, powders, and oral meds
Red to tan spots on the skin linked to genetics and sun
Freckles
moles
Elevated spots on the skin that are benign tumors
Immune system attacks the skin’s melanocytes
Vitiligo
Vitiligo
- Patches of depigmentation across the skin surface
- More noticeable in darker skin
- Runs in families
- may occur in conjunction with other diseases/disorders such as thyroid disease, diabetes, pernicious (harmful) anemia, and autoimmune disorders like multiple sclerosis, systemic lupus erythematosus etc.
Immune system attaching skin or scalp
Psoriasis
Psoriasis
- Red patches, Silvery scales
- Faster cell cycling skin flaking
- Runs in families – immune system related
- Psoriatic arthritis related- attacks cartilage
- Treatment – phototherapy, steroid med, Vitamin D based creams
Inflammation of the sebaceous glands (sebum)
Acne
Acne
- Inflammed sebaceous glands (sebum)
- Teens make more oils so more likely to have infections w/sebum
- Hair follicles blocked with keratinocytes (skin cells)
- White heads – bacteria on skin w/blockage
- Black heads – eventually turned from white heads
- Cleaning with soap/water, healthy eating, antibiotic creams/pills
- Are an infection
Impetigo
- Infection from Staphylococcus or Streptococcus bacteria
- Pus filled blisters; face, arms, legs
- Little kids in kindergarden – sweating on nap mats, microabrasions on skin
- HS atheletes – wrestling on mats, body to body contact, sports pads shared by team
- treatment: clean, dry, antibiotic
Cold sores/herpes
- Whitlow infection (infection on finger from Herpes II, image)
- Target host tissue (skin or glands)
- Herpes I – moist skin, around mouth (cold sores)
- Herpes II – genital tissue that’s moist
- Chicken pox – dry skin
- Itching, painful, virus can spread through blisters breaking
- Store themselves in spinal tissue
- 80% of adults have antibodies
- Kids, babies can get from kisses from infected individuals
- No cure, treatment is to keep clean/dry, meds to reduce itching and pain
Contact dermatitis
- Itching, redness
- swelling of skin, rash
- Usually contact with chemical or substance
- Treatment – doctor directed based on one’s age, causing agent, overall health and medical history
Burns
Skin tissue damage and death caused by intense heat, open flames, electricity, UV/sun radiation, friction injury and certain chemicals and steam/vapors.
Burns can also be classified as partial thickness or full thickness burns in clinical settings.
Partial – 1st and 2nd degree burns, Full – 3rd or 4th degree burns
Degree types of Burns
- First Degree – damage to the epidermis of skin with redness and slight pain. Usually heals in 2-3 days without any special treatment
- Second Degree – involves injury to the epidermis and the upper region of the dermis with skin redness and blistering and some moderate pain. Treatment includes applying cool running water to burn, cleaning and covering it with sterile gauze, and not breaking blisters.
- Third Degree – destruction of the epidermis, all of the dermis and hypodermis and sometimes deeper tissues like muscle and bone. Treatment includes initially covering the burned areas with cool, moist sterile bandages/towels and getting the victim to a hospital or clinic as serious medical treatment will be needed including cleaning and debridement of tissues, antibiotic therapy, fluid replacements, surgery and skin grafting and more likely than not, psychological and psychiatric support.
- Fourth Degree – destruction through all of the skin and injury well within underlying muscle and bone. This is incompatible with life and is an autopsy finding.
Rule of Nines
- Diagnostic tool for 3rd degree burns
- Used by MDs to determine how bad off a person has been impacted
- Divides skin surface into %s to estimate how much damage from burns
Most common skin cancer
Basal Cell Carcinoma
Sun precautions (5)
- Avoiding sun 10-4
- Clothing that covers, avoiding flip flops
- Suncreen 30+ and reapply every 2 hours
- Not tanning salons, type 1 carcinogenic experience
- Low dose asprin may help reduce malignant melanoma
Squamous cell carcinoma
- Lesions throughout epithelium
- Red raised crusty lesion that can flake off
- U shaped hollow ulcer in lesion
- Usually scalp, ears, lower lip, back of the hand
- Good recovery if early detection
- Can be deadly with time – if metasticized to lymphatic system
Malignant melanoma
- Changes in a preexisting mole
- Risk factors, lots of sunburns
- Must be caught early – most deadly skin cancer only 5-15% chance to live
Skin cancer
Malignant cell growths by exposure to UV rays
Skin tips for healthier skin:
- Don’t smoke – samages blood vessels and skin
- Limit alcohol intake
- Eat healthy diet (fruits, grains, fatty fish, lean meat)
- Water and green/black tea
- Manage stress – skin more sensitive with stress
- Treat skin gently – limit bath/shower time (depletes oil), avoid strong soaps, pat dry the body, use a moisturizer that fits your skin type
- Shaving carefully
- Exercise with supportive clothing
- Remove makeup and mild moisturizer on skin
- Inquire about sanitation, wiping tools is ineffective – need UV light and cold sterilization
ABCDE mole assessment
- Asymmetry – mole different top/bottom or L/R
- Border – change on surface
- Color – changes in
- Diameter – distance across the mole
- Elevation/evolution – new elevated surface, change in the mole over time
