Integumentary system Flashcards
3 main sections of the skin
Epidermis
Dermis
Hypodermis
Epidermis:
Type of epithelium:
Functions of:
Keratinocytes
Melanocytes
Lengerhans’ cells
Merkel cells
Stratified squamous epithelium
Keratinocytes: produce keratin
Melanocytes: produce melanin
Lengerhans’ cells: protect skin from infection (macrophages)
Merkel cells: touch receptors
4 layers of epidermis (acronym)
Come Let’s Get Sun burned
Stratum Corneum
Stratum Lucidum (only in thick skin)
Stratum granulosum
Stratum spinosum
Stratum basale
Stratum basale
Only layer with which cells?
Melanocytes/merkel cells
Stratum spinosum
what kind of granules present?
what cells present?
Keratohyaline (strength) + lamellar (water proofing)
Langerhans’ cells
Stratum granulosum
what happens to cells here?
All cells above stratum granulosum are?
Cells “toughen up”
all cells above are dead
Where is stratum lucidum found?
Palms/Feet
Stratum corneum
How much of epidermis?
Functions
What is exfoliating?
3/4 of epidermis
waterproofing + protection
Exfoliating: removing superficial layer of dead keratinocytes from stratum corneum
Merkel discs
Deep/supercficial?
Fast/slow adapting?
Superficial
Slow
Meissner’s corpuscles
Deep/supercficial?
Fast/slow adapting?
Superficial
Fast
Pacinian corpuscles
Deep/supercficial?
Fast/slow adapting?
Deep
Fast
2 layers of dermis? which is bigger/position?
Papillary layer: smaller, superficial
Reticular layer: larger, deeper
Papillary layer:
what type of tissue
Areolar connective tissue
Reticular layer
what type of tissue
how much of skin does it make up?
Dense irregular connective tissue (stretches in different directions)
80% of skin
Hypodermis
what type of tissues?
purpose?
Adipose (insulation) + areolar
Regulates temperature
what 3 pigments contribute to skin colour?
Melanin
Carotene
Hemoglobin
Melanin:
pigment colours
produced by?
cause what abnormalities
Yellow -> black
melanocytes (in stratum basale)
freckles/moles
Carotene
pigment colours
where is it obvious
yellow -> orange
palms/feet
Hemoglobin
pigment colours
excess released when?
red pigment (cause pink hue in skin)
when low oxygen in blood (cyanosis)
Apocrine glands:
activated when?
colour of secretion
Sexual foreplay
milky yellow
Eccrine glands
merocrine/holocrine?
AKA?
high number where
merocrine
SWEAT glands (hypotonic sweat, to cool sin)
High in armpit (acilla)
Ceruminous glands
Combination of which 2 glands
produce what
purpose
Apocrine + eccrine
Ear wax
Block entry of foreign material into ear
Mammary glands: purpose
secrete milk
Sebacous
merocrine/holocrine?
secrete what
what point of life are they activated?
holocrine
sebum
puberty (clogging = acne)
Which type of skin cancer is most dangerous? why
Melanoma
highly metastatic, resistant to chemo
Which skin cancer is least dangerous? why
Basal cell carcinoma
least malignant, surgery is reliable cure
Melanoma: ABCD rule
A: assymetrical
B: border irregular
C: colour is black/brown/tan sometimes blue/red
Diameter: >6mm (pencil eraser)
Burn reaches which layer for each?
1st degree
2nd degree
3rd degree
4th degree
5th degree
1st degree: epidermis (mild sun burn)
2nd degree: papillary dermis
3rd degree: reticular dermis
4th degree: subcutaneous fat (hypodermis)
5th degree: possibly bone/muscle (all sensation lost)
Rule of nines: what % for each?
1 side of 1 leg:
1 side of 1 arm:
1 side of trunk:
1 side of head/neck:
Groin:
1 side of 1 leg: 9%
1 side of 1 arm: 4.5%
1 side of trunk: 18%
1 side of head/neck: 4.5%
Groin: 1%
What constitutes critical burn
> 25% 2nd degree
10% 3rd degree
3rd degree on face or hands or feed
What part of hair produces new hair? How
Hair matrix
Cells are pushed up + keratinized, die
What part of hair causes colours
Melanocytes
What colour is each melanin for? Who is it found in high amounts in?
Eumelanin
Pheomelanin
Eumelanin: balck (black/brown hair)
Pheomelanin: red (blonde/red hair)
3 steps of hair growth?
Growth stage
Resting stage
After resting stage
A person has naturally short hair, how long is their growth stage?
Longer for long hair, shorter for short hair
How long can hair remain in resting stage?
~3 months
How does male pattern baldness (AKA?) occur
AKA androgenic alopecia
Delayed action gene switches on in adulthood, causes increased response of hair follicles to DHT (testosterone)
2 med options for androgenic alopecia
Minoxidil: hair regrowth
Finasteride: prevents hair loss
What part of nail produces new nail?
Nail matrix
