2.2 Integumentary System

Question 1

Which other body systems are most closely integrated with the integumentary system?

Answer 1

Cardiovascular- lots of vessels

Nervous- lots of nerves

Question 2

What makes up the integumentary system?

Answer 2

Cutaneous membrane (Skin)
Epidermis
Dermis
Subcutaneous layer
Accessory structures
Hair
Nails
Glands

Question 3

What are the many functions of the integumentary system?

Answer 3

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

Question 4

What are the layers of the epidermis?

Answer 4

"Come, let's get sun burned" superficial--> deep
· From superficial to deep:
Corneum
Lucidum
Granulosum
Spinosum
Basale

Question 5

Describe the process of keratinazation

Answer 5

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

Question 6

What is they function of keratinocytes?

Answer 6

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

Question 7

What is the function of melanocytes?

Answer 7

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

Question 8

How are skin and hair colored? How does this capability vary between people?

Answer 8

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)

Question 9

What is albinism?

Answer 9

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

Question 10

What is vitiligo?

Answer 10

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.

Question 11

What is melasma?

Answer 11

hyperpigmented areas of skin on face

common with pregnancy (aka chloasma), sun damage

Question 12

What are lentigos?

Answer 12

large pigmented spots on hands, forearm, face

age and sun-exposure related, aka “age-spots”

Question 13

What is the difference between thick and thin skin?

Answer 13

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

Question 14

What causes fingerprints?

Answer 14

Dermal ridges pressing upon the epidermis

Question 15

What are the two layers of the dermis? What type of tissue is the dermis?

Answer 15

Papillary layer
Reticular layer
Mostly connective tissue

Question 16

Describe the papillary layer

Answer 16

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

Question 17

Describe the reticular layer

Answer 17

deepest layer, dense irregular connective tissue

blood vessels, lymphatic vessels, nerves, sensory cells, base of hair follicles, glands

Question 18

Describe the subcutaneous layer

Answer 18

(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

Question 19

What is an abscess?

Answer 19

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).

Question 20

What is a nevi?

Answer 20

“moles”, pigmented or depigmented benign skin tumors

Question 21

What is the acronym for skin lesions/cancer?

Answer 21

ABCDE: 
asymmetry
Border- irregular
Color- varied
Diameter- >6mm
Evolving

Question 22

What is actinic keratosis?

Answer 22

patches of rough, scaly, red plaques

common with fair skin and sun-damage

Question 23

What are the three types of skin cancer?

Answer 23

Melanoma
Basal cell carcinoma
Squamous cell carcinoma
-oma= tumor
carcinoma= cancer of epithelial tissue

Question 24

What is melanoma? What are some risk factors?

Answer 24

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

Question 25

What is basal cell carcinoma? What is its prevalence?

Answer 25

cancer of stratum basalis cells, epidermis
shiny, pearly, white, light pink bump or growth
90% of skin cancer cases, slow growing

Question 26

What is squamous cell carcinoma?

Answer 26

cancer of non-basal layers of epidermis
red, crusted, scaly patch, can ulcerate
can be disfiguring, aggressive, metastatic

Question 27

What is a common fungal skin infection? Consequences?

Answer 27

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:

Question 28

What is the common viral skin infection?

Answer 28

Verrucae (warts)- benign lesions caused by human papilloma virus (HPV)
on genital areas can increase risk of cervical, anal, rectal cancer

Question 29

What causes lyme disease? What is the cutaneous manifestation?

Answer 29

transmitted by ticks carrying Borrelia burgdorferi
characteristic bull’s eye red rash, erythema migrans
fever, chills, headache, abdominal pain, vomiting

Question 30

What are the signs, sx of spider bites?

Answer 30

small puncture wounds, minor pain, redness, itching, swelling, up to severe reactions: cramping, nausea, vomiting, weakness, fever, sweating, difficulty breathing, increased blood pressure

Question 31

What is scabies? In which layer of the skin are they found?

Answer 31

transmitted by mites, mites burrow under stratum corneum,
common irritation sites: interdigital areas, skin folds, nipples, genitalia
common in low hygiene, impoverished conditions

Question 32

What are the accessory structures in skin? From what are they derived?

Answer 32

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

Question 33

What is male pattern baldness? Causes?

Answer 33

hair loss on front, crown, sides of head

genetic and hormonal causes

Question 34

What is telogen effluvium? Causes?

Answer 34

decrease in active hair follicles, not well understood

nutritional deficiency and chronic stress

Question 35

What is alopecia areata? Causes?

Answer 35

loss of hair in patches of scalp
fungal or bacterial infections
autoimmune related

Question 36

What do sebaceous glands do?

Answer 36

Secretes oily secretion (sebum) into hair follicle
Secretes oil onto skin surface
Keeps hair and skin supple, kills bacteria

Question 37

What are the two types of sweat glands? Differences?

Answer 37

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

Question 38

What other glands derive from sweat glands?

Answer 38

Ceruminous glands– waxy secretion, found in ear canal

Mammary gland- breastmilk secretion in lactating mothers

Question 39

What is hyperhydrosis?

Answer 39

excessive sweat production, usually palm, sole of foot, axilla
associated with: febrile diseases, hyperthyroidism, diabetes, sympathetic nervous system stimulant drugs

Question 40

What is anhydrosis?

Answer 40

decreased sweat production
associated with: head injury, trauma, occlusion of sweat ducts, decreased sympathetic activity with peripheral neuritis, burns, radiotherapy, anticholinergic drugs

Question 41

What is acne vulgaris? What types of lesions are associated?

Answer 41

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

Question 42

What is the vitamin D pathway? Why is this important?

Answer 42

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

Question 43

What is rickets?

Answer 43

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