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