Chapter 5: The Integumentary System Flashcards
hypodermis
the layer just deep to the skin; not officially part of the skin, but shares some of the skin’s protective function including shock absorption and insulation
epidermis
most superficial layer of the skin, made up of 4-5 distinct layers; Protection with stratified squamous epithelium
layers of the epidermis (deep to superficial)
Basal Layer, Prickly Layer, Granular Layer, Clear Layer, Horny Layer
cells of the epidermis (4 types)
keratinocytes, melanocytes, epidermal dendritic cells, tactile cells
keratinocytes
produce keratin, a fibrous protein that helps give the epidermis its protective properties
melanocytes
spider-shaped epithelial cells that synthesize the pigment melanin, found in the stratum basale
epidermal dendritic cells (Langerhans cells)
arise from bone marrow and migrate to the epidermis, ingest foreign substances and are key immune system activators
tactile (Merkel) cells
present in the epidermal junction, intimately associated with a sensory nerve ending and serve as sensory touch receptors
thick skin
contains all five epidermal layers, found on the palm, fingertips and soles of feet
thin skin
lacks the stratum lucidum layer, covers the rest of the body
dermis
the second major skin region deep to the epidermis, made up of strong flexible connective tissue
cells of the dermis
typical connective tissue cells; fibroblasts, macrophages, and occasional mast and white blood cells
layers of the dermis (deep to superficial)
reticular layer, papillary layer
melanin
polymer made of tyrosine amino acids which is produced in melanocytes and is one of the main contributors to skin color
carotene
yellow to orange pigment which accumulates in the stratum corneum
skin appendages
nails, sweat glands, sebaceous glands, hair follicles, hair
sweat glands
distributed over the entire skin surface, except the nipples and genitalia, used to regulate temperature
sebaceous (oil) glands
simple branched alveolar glands that are found all over the body expect in the palms and soles; secrete an oily substance called sebum
hairs (pili)
flexible strands produces by hair follicles, constituted of largely dead, keratinized cells
hair follicle
fold down from the epidermal surface into the dermis; deep end is expanded to form a hair bulb. A group of sensory receptors, the root hair plexus, wraps around each hair bulb
hirsutism
excessive hairiness which may result from over production of androgens
nail
scalelike modification of the epidermis that forms a protective covering on the fingers and toes
basal cell carcinoma
the least malignant skin cancer and most common
squamous cell carcinoma
second most common skin cancer which arises from the keratinocytes of the spiny layer
melanoma
cancer of the melanocytes which is highly metastatic
ABCDE rule
A - Asymmetry
B - Border Irregularity
C - Color
D - Diameter
E - Evolution
burn
tissue damage inflicted by intense heat, electricity, radiation, or certain chemicals
rule of nines
divides the body into 11 areas, each accounting for 9% of the total body area, plus 1% for the genital area
first-degree burns
only the epidermis is damaged
second-degree burns
the epidermis and upper region of the dermis is damaged
Third Degree burns
The entire epidermis and dermis are damaged, requires skin grafting to heal.
