2.2 Integumentary System Flashcards
Which other body systems are most closely integrated with the integumentary system?
Cardiovascular- lots of vessels
Nervous- lots of nerves
What makes up the integumentary system?
Cutaneous membrane (Skin) Epidermis Dermis Subcutaneous layer Accessory structures Hair Nails Glands
What are the many functions of the integumentary system?
Protection – pathogens, UV radiation, harmful chemicals
Waste Excretion – excess salts, water, organic waste
Body Temperature – insulation, cooling
Production of melanin – pigment against UV radiation
Production of keratin – tough, water repellant surface
Synthesis of Vitamin D3 – involved in calcium metabolism
Fat Storage – adipose tissue
Sensation – touch, pressure, pain, vibration, temperature
Immune Response – 1st layer of defense, inflammation
What are the layers of the epidermis?
"Come, let's get sun burned" superficial--> deep · From superficial to deep: Corneum Lucidum Granulosum Spinosum Basale
Describe the process of keratinazation
Keratinized stratified squamous only found in skin
Keratin a protei
Surface layers dead, lose most organelles, replaced with keratin
Film of glycoproteins that protect skin by waterproofing
Epithelium, therefore avascular, received everything from dermis below
*No bleeding from an injury contained to the epidermis (bc no vasculature)
Continually replaced by proliferative stem cells in stratum basale
What is they function of keratinocytes?
Majority (99.9%) of skin cells
Produce a protein called keratin
keratin: water resistant, tough, fibrous protein related to intermediate filament protein
Cells on surface have more keratin, cells on surface die from so much keratin
Keratinocytes is the stratified squamous epithelial cells
What is the function of melanocytes?
Produce a pigment called melanin
Cytoplasmic processes inject vesicles of melanin into keratinocytes
Melanin absorbs UV radiation, helps prevent tissue and DNA damage
Large cells, produce pigments, seen deeper in epidermis, towards stratum basale
Skin tone/hair color comes from levels of melanin in the tissue. Everyone has the same number of melanocytes, but the extent to how active they are is genetically derived
How are skin and hair colored? How does this capability vary between people?
All people have the same relative numbers and types of skin cells, but the levels of pigment production vary across individuals Skin and hair color are due to: melanin: yellow-black genetically determined pigment pheomelanin: red-yellow eumelanin: brown-black other influences on skin color bilirubin levels: yellow, jaundiced carotene (dietary): orange-yellow blood flow: increased circulation pink/red decreased blood flow pale, white lack of oxygen cyanotic (blue)
What is albinism?
genetic reduction in melanin pigment in skin, hair and/or eyes
sensitivity to light, optic conditions
range in severity and affected structures
sensitive to UV damage
difficulty with vision common with albinism, lack of melanin creates sensitivity
What is vitiligo?
Discolored patches of skin due to loss of melanocytes
acquired condition increased in autoimmune and thyroid dysfunction
A “patch” of melanocytes are killed, causing vitiligo.
What is melasma?
hyperpigmented areas of skin on face
common with pregnancy (aka chloasma), sun damage
What are lentigos?
large pigmented spots on hands, forearm, face
age and sun-exposure related, aka “age-spots”
What is the difference between thick and thin skin?
Thick skin: found on palms of hands, soles of feet
all 5 layers (strata), thicker stratum corneum
n palmar/plantar surface. Extremely thick stratum corneum. Thick skin doesn’t have hair.
Thin skin: found on rest of the body
4 layers (strata), no stratum lucidum, thinner stratum corneum
On the majority of the body. Only 4 layers. No stratum lucidum
What causes fingerprints?
Dermal ridges pressing upon the epidermis
What are the two layers of the dermis? What type of tissue is the dermis?
Papillary layer
Reticular layer
Mostly connective tissue
Describe the papillary layer
layer just underneath the epidermis
areolar connective tissue
Dermal papillae -form epidermal ridges
blood vessels, lymphatic vessels, nerves, sensory cells
forms bumps that push up unto epidermis, deep to epidermis, primarily areolar CT
BC areolar CT, has vasculature, nerves
Describe the reticular layer
deepest layer, dense irregular connective tissue
blood vessels, lymphatic vessels, nerves, sensory cells, base of hair follicles, glands
Describe the subcutaneous layer
(hypodermis or superficial fascia)
Deep to the dermis, mostly adipose and some areolar CT
Anchors skin to underlying muscle
Allows skin to slide relatively freely
Energy reserve, insulation, shock absorber
What is an abscess?
buildup of pus (inflammation, white blood cells, bacteria) in or on the skin, multiple causes
bacterial infection (often staphylococcus)
wound or injury
boils
folliculitis
warm compress, drainage, may need to be further cut open, cleaned and drained
if untreated, can spread to nearby areas, spread to the blood, other organs, lead to localized tissue death (gangrene).
What is a nevi?
“moles”, pigmented or depigmented benign skin tumors
What is the acronym for skin lesions/cancer?
ABCDE: asymmetry Border- irregular Color- varied Diameter- >6mm Evolving
What is actinic keratosis?
patches of rough, scaly, red plaques
common with fair skin and sun-damage
What are the three types of skin cancer?
Melanoma Basal cell carcinoma Squamous cell carcinoma -oma= tumor carcinoma= cancer of epithelial tissue
What is melanoma? What are some risk factors?
cancer of melanocytes, spreads to up epidermis, then through dermis where it can metastasize
brown, black, or light colored bump or growth
risk factors: fair skin, multiple moles, irregular moles, history of tanning or sunburn, family history, immunosuppression, age over 50.
most concerning when penetrates down to dermis- b/c mets can come from access to lymph/blood systems
What is basal cell carcinoma? What is its prevalence?
cancer of stratum basalis cells, epidermis
shiny, pearly, white, light pink bump or growth
90% of skin cancer cases, slow growing
What is squamous cell carcinoma?
cancer of non-basal layers of epidermis
red, crusted, scaly patch, can ulcerate
can be disfiguring, aggressive, metastatic
What is a common fungal skin infection? Consequences?
Tinea (ringworm)- skin, hair and nail infection can cause scaling, nail disintegration, broken hairs
topical and antifungal agents
invasive fungi can lead to blood infection, septicemia
viral:
What is the common viral skin infection?
Verrucae (warts)- benign lesions caused by human papilloma virus (HPV)
on genital areas can increase risk of cervical, anal, rectal cancer
What causes lyme disease? What is the cutaneous manifestation?
transmitted by ticks carrying Borrelia burgdorferi
characteristic bull’s eye red rash, erythema migrans
fever, chills, headache, abdominal pain, vomiting
What are the signs, sx of spider bites?
small puncture wounds, minor pain, redness, itching, swelling, up to severe reactions: cramping, nausea, vomiting, weakness, fever, sweating, difficulty breathing, increased blood pressure
What is scabies? In which layer of the skin are they found?
transmitted by mites, mites burrow under stratum corneum,
common irritation sites: interdigital areas, skin folds, nipples, genitalia
common in low hygiene, impoverished conditions
What are the accessory structures in skin? From what are they derived?
Accessory structures of the skin are: hair follicles & hair sebaceous glands suderiferous (sweat) glands nails Most are derived from the infolding of the epidermis during development
What is male pattern baldness? Causes?
hair loss on front, crown, sides of head
genetic and hormonal causes
What is telogen effluvium? Causes?
decrease in active hair follicles, not well understood
nutritional deficiency and chronic stress
What is alopecia areata? Causes?
loss of hair in patches of scalp
fungal or bacterial infections
autoimmune related
What do sebaceous glands do?
Secretes oily secretion (sebum) into hair follicle
Secretes oil onto skin surface
Keeps hair and skin supple, kills bacteria
What are the two types of sweat glands? Differences?
Merocrine (eccrine) glands – coiled tubular gland, duct opens to the skin surface
Watery secretion, “perspiration”
Widely distributed: abundant on hands, feet, and face
Apocrine glands – ducts empty into hair follicles
Confined to axillary and genital regions
Produce milky sweat – water with lipids and protein
What other glands derive from sweat glands?
Ceruminous glands– waxy secretion, found in ear canal
Mammary gland- breastmilk secretion in lactating mothers
What is hyperhydrosis?
excessive sweat production, usually palm, sole of foot, axilla
associated with: febrile diseases, hyperthyroidism, diabetes, sympathetic nervous system stimulant drugs
What is anhydrosis?
decreased sweat production
associated with: head injury, trauma, occlusion of sweat ducts, decreased sympathetic activity with peripheral neuritis, burns, radiotherapy, anticholinergic drugs
What is acne vulgaris? What types of lesions are associated?
inflammation of sebaceous glands commonly seen on face, chest, back
papules: small raised lesion
pustules: small pus-filled lesion
nodules: larger, solid, raised lump
comedone: typical acne lesion, near hair follicle, plugged with sebum, cellular material
blackhead (open)
whitehead (closed)
common in puberty, when hormones increase activity of sebaceous glands
topical agents and antibiotics recommended
What is the vitamin D pathway? Why is this important?
Vitamin D3 (cholecalciferol) is produced by epidermal cells when exposed to UV light, it is necessary for calcium absorption.
Process integrates the skin, liver, kidneys, and digestive system:
Vitamin D3 is made in the skin, a pre-cursor to the steroid hormone calcitriol.
Vitamin D3 is converted by the liver and kidneys to produce Calcitriol (active Vitamin D)
Calcitriol is necessary for absorption of calcium and phosphorous in the small intestine
What is rickets?
low calcium or phophorous levels in children causes softening and weakening of bones
bone tenderness, dental problems, increased fracture, bone deformity, growth problems, muscle weakness or spasms, tetany, seizures, cardiomyopathy, enlarged spleen and liver, overgrowth of cartilage
varus deformity (leg bowing)
“rickety rosary” (costochondral swellings)
lumbar lordosis
greenstick fractures
lack of Vitamin D or lack of calcium
low UV (sunlight) exposure (10-30 mins per day recommended)
low dietary intake of Vitamin D (400-1000 IU recommended)
breastfed infants
malnutrition
lack of absorption due to other medical conditions
gastrointestinal malabsorption
renal disorders
