Derm- pp1 Flashcards
what are the basics of the skin?
- largest organ
- temp, insulation, sensation control
- physical/ immunologic barrier
what do the skin components include?
epidermis
dermis (oil, hair, nails)
subcutaneous fat
epidermis layers: (bottom to top)
basal cell stratum spinosum stratum granulosum stratum corneum * includes melanocytes & langerhans cells
why is the job of the basal cells?
how long does it take for cells to migrate up & shed?
- undifferentiated proliferating cells
- as they migrate up, they begin the process of differentiation
2. FOUR WEEKS
why is the stratum spinosum important?
contains keratinocytes
why is the stratum granulosum important?
cell differentiation occurs here.
cells acquire more keratin and become flatter
polysaccharides, glycoproteins and lipids are found in this layer, holding the corneum together.
- why is the stratum corneum important?
2. what do these cells look like?
- major physical barrier
2. cells are large, flat, filled with keratin, stacked in vertical layers.
in the stratum corneum, how many layers are on most surfaces of the body?
palms and soles?
15- 25 on most layers
100 on palms and soles
what are two types of cells found in the epidermis?
melanocytos
- pigment producing cells found in basal cell layer
- protect from UV
langerhans cells
- immunologic function, found in none marrow
what are langerhans cells identical to ?
tissue macrophages and present antigens to lymphocytes
what is the dermis?
- next layer down, tough, elastic.
- contains nerves, blood vessels, appendages
- contains collegen
how this is the dermis?
1-4mm
what do the appendages consist of?
- eccrine sweat glands
- appocrine sweat glands
- hair follicles
- sebaceous glands
- nails
what do eccrine sweat glands do ?
regulates body temp
cools body by sweat evaporation
triggered by emotional and temp stimuli
- about how many sweat glands do we have in our body?
2. how much sweat can the body secrete a day?
- two- three million
2. 10 liters
- what does the appocrine sweat glands do ?
2. where are they found?
- no purpose, produces body odor
odor caused by surface bacteria - axillae, anogenital areas: located deep in the dermis, reaching skin via hair follicle
- what does the hair follicle do?
- where are they located?
- what are the 2 types of hair?
- protective and decorative
- everywhere except palms & soles
- -vellus hair (peach fuzz)
- terminal hair
what are the 3 cycles that hair grows?
- anagen growth
- catagen growth
- telogen growth
* hair varies person to person
- what to sebaceous glands produce?
- where are they located?
- how is size & activity of these glands regulated?
- sebum.
- wherever hair follicle is present, mainly scalp & face
- androgen control, reaches full size at puberty
what are nails made up of?
how fast do nails grow?
- keratin, formed from dividing epidermal cells
2. 0.1 mm/day (toe nails grow slower)
what does the proximal nail fold do?
protects nail matrix
contains cuticle
what does the nail matrix do?
produces nail plate
most of matrix lies under prox. nail fold
where does subcutaneous fat lie?
what is fat for?
- between dermis & fascia
2. insulation, cushion, & energy reserve
what is the term for ‘feeling itchy’
what is the term for scratching?
puritis
excoriation
