Integumentary System
when injury occurs, bleeding generally occurs followed by inflammation resulting in enhanced blood flow to the surrounding region. then: 1. blood clot, scabs 2. blood proteins, fibrin form 3. granulation tissue(clot, fibroblasts, capillaries) form 4. scar tissue forms
How do skin injuries heal?
fibrin
a blood clot, or scab, is made mostly of an insoluble network of ____ produced by blood proteins during the clotting process
"goose bumps"
activated arrector pilli
stabilize the position of the skin in relation to underlying tissues
an important function of the hypodermis is to
a third-degree burn
burn all the way down to the hypodermis, damages nerves and vessels, need skin graft
melanin is not produced by the melanocytes
even though melanocytes are of normal abundance and distribution, in the inherited condition of albinism
base of a hair follicle
hair production begins at the
decreased melanocyte activity
hair turns gray or white due to
subcutaneous layer
hypodermis
melanocyte activity
in older Caucasians, the skin becomes very pale because of a decline in
glandular activity
in older adults, dry and scaly skin is usually a result of a decrease in
stratum lucidum
in thick skin, such as the palms of the hands and soles of the feet, the epidermis contains an additional layer called the
melanoma
life-threatening skin cancer
nail root
nail production occurs at an epithelial fold not visible from the surface called the
sweat glands
natural body odor is produced by the
epidermis
no blood vessels
decreased sensitivity of the immune system
one factor that can lead to increased skin damage and infection in the elderly is
sweat glands
perspiration is produced by the
a decrease in the elastic fiber network of the dermis
sagging and wrinkling of the integument results from
a first-degree burn
severe sunburn, epidermis
Vitamin D3
small amounts of ultraviolet(UV) radiation are beneficial because it stimulates the synthesis of
new cells are generated and skin colors are synthesized
stem cells and melanocytes dominate the stratum basale, making it the layer where
round, flat
straight hairs are ____ in cross section; curly hairs are more ____
a second-degree burn(epidermis and maybe dermis)
the appearance of blisters and very painful sensations is indicative of
nail bed
the body of the nail covers an area of epidermis called the
keratin
the dead epithelial cells that make up the stratum corneum have accumulated a large amount of ____, an extremely durable and water-resistant fibrous protein
1. protection 2. temperature maintenance 3. synthesis and storage of nutrients 4. sensory reception 5. excretion and secretion
5 functions of the Integumentary System
1. cutaneous membrane(skin)- an organ composed of superficial epithelium or epidermis and the underlying connective tissue of the dermis 2. accessory organs- including hair, nails, and some exocrine glands
2 components of the Integumentary System
1. blood supply 2. concentrations of melanin and carotene
2 factors that the color of pigmentation depends on
1. carotene- orange/yellow pigment, less evident in individuals with darker skin, can be converted to vitamin A which is required for epithelium tissue 2. melanin- brown, yellow/brown, or black produced, melanocytes protect stem cells from UV light, freckles represent greater than average melanin production
2 types of pigment in the skin that help give the skin its unique color
1. thick skin- found on palms and soles of feet and contains 5 layers 2. thin skin- covers the rest of the body, 4 layers thick, similar to the wall of a plastic bag
2 types of skin in the epidermis
1. hair- nonliving structures that extend from the surface of the skin; functions: protection from UV light, guard entrances from foreign particles; pigment production decreases with age and hair lightens hair follicle- extends deep into the dermis and usually hypodermis, covered by connective tissue and base contains nerves and capillaries; functions: nerve stimulation, blood supply, connects to arrector pili muscle for hair to stand up 2. sebaceous glands- oil glands, discharge oily lipid secretion; , contraction of arrector pili muscle squeezes the gland and forces secretions onto hair follicles; secretions accelerate at puberty, which may lead to acne 3. sweat glands- release fluid(99% water and 1% electrolytes), lower body temperature, dilutes harmful environmental chemicals found on skin 4. nails- kertainizes epidermal cells that protect the fingers and toes. the nail body is dead cells. nail production occurs at the nail root. underlying blood supply gives the nail its pink appearance
4 types of accessory organs found in the integumentary system
1. skin injuries and infection became more common 2. sensitivity of the immune system reduced 3. muscles become weaker, bone strength decreases 4. sensitivity to sun exposure decreases 5. skin becomes dry and scaly 6. hair thins and changes color 7. skin becomes saggy and wrinkly 8. ability to lose heat decreases 9. skin repairs proceed more slowly
What are the effects of aging on the skin?
1. lies beneath the epidermis 2. consists of areolar tissue that supports and nourishes the epidermis and dense, irregular connective tissue called elastic and collagen fibers that connect dermis layer to hypodermis 3. contains capillaries and nerves, hair follicles, sweat glands
characteristics of the dermis layer
1. contains connective tissue fibers that attach the dermis to the hypodermis and areolar tissue 2. contains adipose cells, arteries, and veins
characteristics of the hypodermis or subcutaneous layer
papillary layer(dermis)
contains capillaries and nerves
nerve fibers
control of blood flow, adjustment of glandular secretion rates, and monitoring of sensory receptors in the dermis is regulated by
decreased blood supply to the dermis and decreased sweat gland activity
dangerously high body temperatures occur sometimes in the elderly due to
produce skin color
dermal blood supply and epidermal pigmentation are the two basic factors interacting to
levels of melanin synthesis
differences in skin color among individuals reflect
developing acne(oil clog)
during adolescence, the sebaceous glands are especially prone to
reduction of melanocyte activity(no coloration)
the development of gray hair is due to the
stratified squamous epithelium
the epidermis consists of ____ cell layers which consists of 2 types of skin
a blood clot, fibroblasts, and an extensive capillary network
the granulation tissue that appears during the healing process is a combination of
calcitrol
the hormone essential for the normal absorption of calcium and phosphorus by the small intestine is
areolar tissue(loose connective tissue) and adipose cells
the hypodermis consists of
bleeding occurs(cut capillary), and mast cells trigger an inflammation response
the immediate response by the skin to an injury is that
basal cell carcinoma
the most common form of skin cancer caused by exposure to UV radiation and sunlight is
the type of pigment present
the natural factor responsible for various shades of hair color is
melanin
the pigment that absorbs ultraviolet radiation before it can damage nuclear DNA is
cuticle
the portion of the stratum corneum of the epithelial fold that extends over your exposed nail, nearest the root, forms the
scar tissue(last stage of healing)
the practical limit to the healing process in the skin is the formation of inflexible, fibrous, noncellular
limited number of capillaries and no vital organs
the reason the hypodermis(lower level of skin) is useful for subcutaneous(skin) injection by hypodermic needle is that it has a
hard keratin
the shaft of the hair is stiff due to the presence of a protein substance called
carotene and melanin
the two pigments contained in the epidermis in variable amounts are
nail body
the visible dense mass of dead keratinized cells is the
keloid
thickened area of scar tissue
blood vessels, lymphatic vessels, nerve fibers
what allows the dermis to communicate with other organ systems?
1. basal cell carcinoma- most common, looks like a waxy bump 2. squamous cell carcinomas- involves superficial layer of epidermis 3. malignant melanomas- begins from a mole, cancer cells metastasize quickly through the lymphatic system
what causes skin cancers?
vitamin D3
when exposed to ultraviolet radiation, epidermal cells in the stratum basale convert a cholesterol-related steroid into