SENIOR INTEGUMENTARY

SYSTEMJ.J.NELSON RN,CMAEdited by B. Speck, RN

You are likely to shed some 40 pounds of skin in a lifetime.

Average head holds around 120,000 hair. Freckles are called “ephelides” One square inch of skin has 65 hair, 100 oil

glands, 650 sweat glands and more nerves and blood vessels than you can count.

The skin leaks about one pint of fluid/day. This is called “insensible perspiration”

Did you know?

INTEGUMENT SKIN WITH ASSOCIATED SEBACEOUS

AND SWEAT GLANDS

HAIR

NAILS

FUNCTIONS Protection-How? Temperature Regulator-How? Excretion of water and salts. Sense Organ-Which senses? Storage- What? Production and Secretion? – What Absorption-How?

Protection Intact skin is the body’s first line of defense

Covering for underlying deeper tissues

Protects against dehydration

Protects against injury

Doesn’t allow the invasion of microorganisms

Temperature Regulation Body Temperature is regulated by controlling the

amount of heat loss Increased body temp—BV dilate and sweating increases Skin evaporates water from skin as perspiration to get rid

of heat Low body temp=chilling to produce heat & BV constrict One pint of water is lost in 24 hrs-called insensible

perspiration—occurs by way of diffusion Strenuous workout=millions of pours open to cool you You can sweat 3 gals or 11.4 L in 24 hrs Heavy sweating can be harmful—depletes vital body salts Sweating makes you thirsty-you drink=diluting salt reserves

and possible leading to heat exhaustion

Excretion of Water & Salt The skin is meant to excrete water and salts This is a normal function Also excretes a small amount of waste

through skin; ammonia and urea.

Sense Organ Skin well supplied with nerves: allows us to be

sensitive to hot/cold, pain, pressure, & touch Touch is vital for emotional growth Sense of touch protects us…..heat, cold, pain,

pressure & touch Hair acts as antenna’s Areas without hair have “special alarm

systems”….lips, nipples, external sex organs supplied with extremely sensitive receptors

Sense Organ Cont. Deep in skin are receptors that record

continuing pressure on skin….palpation Receptors that sense vibration, hot and cold

Pulse vibration, Hot and cold temperature of skin on others

Storage Skin has tissues for temporary storage of fat,

glucose, water and salts Some of these can be later reabsorbed by

blood as needed in body Skin turgor=normal tension of skin and fluid

storage in skin

Skin Turgor

Production and Secretion Skin produces Melanin Also produces Keratin=a flexible protein that

forms a formidable barrier to skin Horny=hard=rough=keratinized=epidermis It protects underlying tissue from

microorganisms, bars entry of chemicals & minimized mechanical injury

Our skin tissue is abundant with bacteria due to the oil and sweat in them

Absorption Skin absorbs certain drugs and chemicals The administration of drugs through the skin

is called?........ What if our skin absorbs harmful chemicals?

Structure of Skin

Epidermis (stratified squamous)

Dermis (dense fibrous CT)

Subcutaneous(loose ordinary CT)

What is a blister?

View Animation http://www.pennmedicine.org/encyclopedia/e

m_DisplayAnimation.aspx?gcid=000029&ptid=17

THICK SKINThe thickness of skin outer layer of the epidermis (Stratum Corneum) isDetermined by the amount of stimulation on the surface. Such as weight bearing and abrasion. Hence the soles of the feet and palms of the hands are the thickest.

Thick and Thin Skin

EPIDERMIS Stratum

Corneum Stratum Lucidem Stratum

Granulosum Stratum

Spinosium Stratum Basale

Stratum Corneum Outermost layer: 20-30 cells layers thick Accounts for ¾ thickness of epidermis Cytoplasm in SC is replaced with Keratin. Keratin are hard non-living protein (dead skin

cells) SC is referred to as horny layer, horny cells

or cornified These dead cells are surrounded by lipids

which help to prevent fluid loss

Video of keratinization https://www.youtube.com/watch?v=OKosGS

m7Ps4

The SC rubs & flakes off slowly & is replaced by the cells from the Stratum Germinativum in Basale layer

We have a “new” Epidermis every 35-45 days!

SC is first line of defense from bacteria due to being slightly acidic, thus killing bacteria

What is a callus? What is a corn?

Stratum Lucidum “clear layer”—this layer is absent in thin skin,

but is apparent on sections of thick skin like soles of feet and palms of hands.

SL is layer of 1-2 cells thick Made of squamous flattened cells Helps with water repellant of skin

Stratum Granulosum A very thin layer consisting of 2-3 cell layers

of flattened squamous cells This is were keratinization begins. Cells appear granular-thus giving name to

this layer.

Stratum Spinosum “Prickly layer”—consists of several rows of

cells with slender projections or spiny processes that connect them with other layers.

Helps to maintain one of the daugther cells from mitosis that occurs in Basal layer

Forms Stratum Germinativum with Basal layer

Stratum Basal Deepest & most important layer of skin Contains cells capable of mitotic division,

thus this layer makes the new skin cells This process of making and moving new cells

up to SC takes about 26 days. This layer gives rise to outer layers of

epidermis This layer is also the basement membrane

which offers further protection from environment.

Color of Skin Skin pigmentation is found in germinativum

cells called melanocytes Melanocytes contain a skin pigment called

Melanin. The amount of melanin in the melanocytes

determines the various shades of skin color. Exposure to sunlight stimulates the

melanocytes to produce melanin, thus=?

Skin Color

• What happens when you tan?

•What is a freckle?•What is a nevus?

• What is the conditionof not producingmelanin?

What is an albino?

http://www.youtube.com/watch?v=oWTgu1paGDs

What are fingerprints?

epidermal ridges - The series of unique genetically determined patterns of narrow, raised strips of epidermis which are located on the palms of the hands and soles of the feet which increase friction and, therefore, traction of the foot and gripping ability of the hand; the pattern of these ridges is regulated by heredity.

Fingerprints Lower edge of S. Spinosum & Basale (=S

Germinativum) are thrown into ridges. Ridges are known as papillae of skin Also called ‘friction ridges” to help reduce

slipping when gripping or grasping things Fingerprints remain the same all life, unless

the S. Germinativum is destroyed or major injuries

Simian fold

Dermis (Corium) Thicker, inner 2nd layer of skin. Our “hide” Thickness & Thinness of skin varies over

body It is the strong, stretchy envelope that holds

body together. Has 2 layers: Papillary Layer & Reticular

layer

Functions of Dermis Gives mechanical strength to skin

Protects against mechanical injury

Storage for water and electrolytes

Sensory for nerve receptors

Papillary Layer of Dermis Is upper part of dermis Has fingerlike projections called papillae,

which project into lower part of Epidermis. Composed of loose connective tissue, thin

collagenous & elastic fibers Makes ridges of fingerprints & holds nerve

endings for pain receptors and touch receptors

Reticular Layer of Dermis Thicker layer, which lies beneath papillary

layer. Contains network of interlacing cells & fibers

for BV, sweat & oil glands and deep nerve receptors

Composed of collagenous fibers & elastic fibers for toughness & stretch

Nerve Receptors Raffini Corpuscles=Heat

Krause Corpuscles=Cold

Meissners Corpuscles=Touch

Pacinian Corpuscles=Pressure

“E” End Organ of Ruffini= Heat

“D” End Organs of Krause=Cold

“B” Meissners Corpuscles=Touch

“C” Pacinian Corpuscles=Deep Pressure

Structure

STRIAE

Fresh tears of the elastic fibers look pink (or slightly bluish) with ragged edges. Healed the marks look silver-white.

HAIR

S.Pocklington

HAIR

Hair is mainly composed of a protein called keratin (about 88%). Keratin starts out as a soft substance arising from the follicle and keratinizes (hardens) as it rises up and out into the hair shaft. Keratin is insoluble, very tough, and highly elastic.

Functions of Hair Cushions Insulation Antenna Filter Sweat Bands

The Three Layers

The cuticle

The Cortex The medulla

S.Poklington

The cuticle

The cuticle is the outer layer of the shaft.

Keratinized simple squamous tissue

The closed cuticle feels smooth

Split Ends

Split ends are a result of cuticle wearing away at the tip of the shaft

The cortex Cortex comprised of

elongated keratinized nonliving cells.

Comprising 75- 80% of the hair’s protein structure.

Gives hair its strength and elasticity

The hair pigment is located in the cortex

S.Pocklington

Medulla

MedullaThe central axis of hair, containing a column of soft keratinized cells interspersed with air pockets, helping to give hair its elasticity.

HAIR

Hair is a complicated structure that comprises of the root and the shaft (the visible part of hair). The root is enclosed in the hair follicle, submerges into the skin in inclination and ends down to the bulb

Hair is produced in the hair bulb which rest on a nipple like papilla (tuft of tissue).

These biological structures are very important to the follicle, as they bear capillary vessels which send nutritive elements from blood to cell.

Hair grows in stages. Some hair bulbs are active while others are at rest.

Hair is formed by epithelial cells in the bulb are keratinized as they push upwards. Thus the hair root and shaft consist of columns of dead keratinized epithelial cells

HAIR COLOR

The melanocytes present in the hair bulb are responsible for hair color.

Age causes fading of melanin.

Arrector Pili muscle contraction results in “goose bumps”

NAIL The visible part of the nail

(nail body or nail plate) consists of layers of stratum corneum cells that are keratinized.

Nails function: Protection of fingers/toes Antennae Assist with delicate task

Nail Root is beneath the skin. The stratum basale and spinosum of epidermis are present

here forming nail matrix cells which synthesize the nail plate.

These cells contain no melanocytes…so are seen as white. The crescent shaped structure is called the lunula.

Nail bed: As the nail is being produced by the root, it streams down

along the nail bed which adds material to the undersurface of the nail to make it thicker.

Smooth nails depend on a smooth nail bed.

Eponychium (cuticle) is the junction between skin stratum corneum and base of nail plate.

The term hyponychium refers to area between the nail plate and the fingertip. It provides a waterproof barrier

REALLY?

SUDORIFEROUS GLANDS Sweat glands are simple

tubular glands found in most parts of the body.

MEROCRINE (also called Eccrine) secrete sweat, a mixture of 99 percent water and 1 percent salts and fats. “Sensible perspiration”

APOCRINE glands, become active at puberty, are larger, deeper, and produce thicker secretions than eccrine glands.

Located in axilla, and genital-anal areas. Unlike eccrine glands that respond to heat,

apocrine glands respond to stress and sexual activity by secreting sweat with a characteristic odor. This odor differs from body odor that results from bacteria decomposing skin secretions on the skin.

Sweat gland animation http://www.pennmedicine.org/encyclopedia/e

m_DisplayAnimation.aspx?gcid=000127&ptid=17

CERUMINOUS GLANDS

Ceruminous glands are modified apocrine glands in the external ear canal lining. They secrete cerumen (earwax), a sticky substance that is thought to repel foreign material.

Mammary glands in female breasts are modified apocrine glands. These glands are adapted to secrete milk instead of sweat.

SEBACEOUS GLANDS

Sebaceous glands are all over the body except on the palms of hands and soles of feet.

The glands empty via ducts into the bases of hair follicles and secrete sebum (a lipid substance).

Sebaceous glands are numerous on the face and scalp.

Sebaceous Gland

Terms: Alopecia

DERMATOLOGY TERMS

THE END.