lec 4 integument system

the four organs of the integument system are the __________

Organs

a. Skin

b. Hair

c. Nails

d. Glands

the largest organ of the integument system is ______

the skin (and is the largest organ in the body)

5 functions of the integument system are

1. Protection from:

• Abrasion

• Infection

• UV light

• Dehydration

2. Thermal regulation

• insulation (adipose layer)

• cooling (sweat glands)

3. sensory reception

4. vitamin d production

5. communication

3 layers of skin

epidermis

dermis

hypodermis

characteristics of the epidermis

provides:

strength

protection

has NO vasularization

the epidermis gets nutrients through __________

absorbing nutrients from the tissues deep to it

nails are made in the ____________ layer of skin

epidermis

epidermis layers

All epidermis has four layers (thick skin has a fifth

layer):

Stratum basale (deepest layer of epidermis)

Stratum spinosum

Stratum granulosum

Stratum lucidum (only in thick skin)

Stratum corneum (most superficial layer of

epidermis)

four cell types found in the STRATUM

BASALE

1. Main cell type=KERATINOCYTES

Keratin=protein:

• provides waterproofing

• strength to

• keratinocytes do not start producing keratin until they get closer to the surface

2. MELANOCYTES

• produce MELANIN (dark

brown pigment)

3. MACROPHAGES

• ingest and destroy cells

4. MERKEL CELLS=nerve fibers

• sensory receptors for light touch

characteristics of the stratum spinosum

cells stop dividing and are attached to each other by desmosomes

provides strength to the epidermis

where Langerhans cells are found

Langerhans cells

found in stratum spinosum

Red bone marrow, along with other white blood cells

characteristics of the stratum granulosum

cells start to die in this layer from lack of nutrients—they are too far from the nutrient source in connective tissue

characteristics of stratum corneum

the main difference between thick skin and thin skin relates to the thickness of this layer

it takes _________—______ days for a cell to migrate from the stratum basale to the stratum corneum

about 15-30 days

dead cells remain in the stratum corneum layer about _____ weeks before they shed

about 2 weeks

characteristics of the stratus lucidum

only in palms and soles

has cells that provide protection from uv radiation

directly under stratum corneum

when you get a blister, these two areas seperate from eachother

stratum basale tears away from the basement membrane

vesicle

blister smaller than 5 mm

bulla

blister larger than 5 mm

the skin is capable of repair even after serious damage because

stem cells persist in both the dermis and epidermis

3 major types of skin cancer are

1) BASAL CELL CARCINOMA:

• most common, least

deadly

• symptoms are easily seen shiny nodules on the

nose

2) SQUAMOUS CELL CARCINOMA

3) MELANOMA

• least common, most deadly

a major risk for skin cancer is

UV light

a skin cancer that is most easily cures and usually doesnt matastasize

basal cell carcinoma

a skin cancer that is most likely to matastasize

melanoma

medical term for a mole

nevus (plural =nevi)

medical term for freckle/other pigmented area that is flat/doesn’t stick upwards from skin

macula

medical term for scratch marks

Excoriations

medical term for dry skin

Xerosis

medical term for inflamed skin

Dermatitis

itchy red skin that comes and goes, caused by an autoimmune reaction

Eczema

most frequent eczema: dermatitis

3 things that might trigger Atopic dermatitis

• allergens like:

  • soaps

  • cosmetics

  • clothing

  • detergents

  • jewelry

  • sweat

• changes in weather

• stress

poison ivy causes what type of skin condition

Contact dermatitis

the name for severe dandruff

Seborrheic dermatitis

Seborrheic dermatitis is caused by

an allergy to the fungus that we all

have around our hair roots

cause of Psoriasis

an autoimmune disease of the skin

symptoms of psoriasis

silvery flakes on the elbows, knees, and scalp

NOT itchy

the skeletal condition which psoriasis associated with

arthritis and a pencil-in-cup appearance on x-ray

the two layers of the dermis

1. PAPILLARY LAYER

• Papillary = “Pimple” (has

bumps)

• more superficial layer.

2. RETICULAR LAYER = deeper layer

this layer is responsible for fingerprints

PAPILLARY LAYER is in the DERMIS

strongest layer of the epidermis

Stratum spinosum

strongest layer of the dermis

Reticular layer

strongest layer of the skin

Epidermis

layer of the SKIN responsible for stretch marks

Dermis

all glands of the body are located

DERMIS

the layer of the skin is the area that a transdermal patch must reach

DERMIS

the layer of the skin that generates the pink color seen in Caucasian people

DERMIS

Doctors make incisions on the body based on the lines of cleavage of this layer of skin

DERMIS

nerve fibers in the reticular layer of the dermis for vibration and pressure

Pacinian corpuscles

nerve fibers in the papillary layer of the dermis for light touch

Meissner's Corpuscles

causes of stretch marks

During expansion of skin, collagen fibers in the DERMIS separate = stretch marks

• Caused by Sudden weight gain (often seen in

pregnancy)

Layer in the skin that consists of fibrous tissue, blood vessels and nerves; sits on top of the muscles

hypodermis

functions of the HYPODERMIS

1) Stores fat

2) Cushions

3) Insulation of heat from blood vessels in this layer.

4) Stabilizes the position of the skin in relation to

underlying tissues

cosmetic surgical procedure is performed in the hypodermis

Liposuction

cellulite is what kind of tissue

there is no such thing as cellulite!

it is not a type of adipose or connective tissue—it is not a specific region of skin

3 types of burns

FIRST DEGREE: Minor burn to the epidermis;

sunburn

 SECOND DEGREE: Dermis separates from

epidermis; blister

 THIRD DEGREE: Hypodermis is burned. (most

severe type of burn; needs a skin graft)

2 reasons why deep burns are so dangerous

1)Infection

2) Dehydration: nothing to keep fluid in body.

when epidermis is destroyed, and underlying tissue is exposed

DECUBITUS ULCERS

the pigment that produces brown coloration to the skin

MELANIN: (dark brown pigment). More melanin,

darker the skin

this pigment accumulates more in Asian skin types

CAROTENE: (a yellowish/orange pigment).

Accumulates more in Asian skin types

darker-skinned people have lighter palms and soles because

the thick stratum lucidum layer of the palms and soles blocks the appearance of the melanin pigment in the deeper layers

the pink color of caucasian skin comes from

HEMOGLOBIN in red blood cells in the blood vessels in the DERMIS

Melanin, carotene, skin thickness, and hemoglobin all determine:

skin color

medical term for a bruise is a:

contusion

Bluish color to skin caused by superficial blood vessel constriction in the

dermis OR lack of blood flow to skin

cyanosis

4 things that cause cyanosis

1) Cold

2) Not enough oxygen in body to go around.

• oxygen is conserved for the vital organs, so oxygen to

skin and nails is shut down.

3) Certain medicines

4) Certain chemicals may cause cyanosis

wrinkles form because:

collagen fibers align themselves more and more as they are always being pulled in the same direction: smile, frown.

Skin begins to sag because body makes less elastin.

botox is:

1. a deadly poison (botulism) which paralyses the muscles, making them sag

2. Without muscle tension, wrinkles relax.

3. In 3 months, new muscle cells are made, so wrinkles

come back, and need new injection

COLLAGEN INJECTION is used for cosmetic reasons by:

being injected into hypodermis to fill out deep

wrinkle lines.

• Can last a couple of years.

• Collagen can also be injected into the lips to make them

appear fuller, but in this area, it degrades faster, so new

injections are needed more often.

ink is injected into this layer for tattoos

dermis

vitamin _____ is produced by the dermis

vitamin D

tiny muscles that make the hair stick up when you are cold, as in “goosebumps”

Arrector Pilli

the _________are destroyed during electrolysis so hair won’t grow back

dermal papillae

hair is made of:

dead skin cells

qualities of the hair matrix

part of the hair follicle that is the site of hair growth

the location of the melanocytes that determine hair

color

differences in uncut hair length are caused by

variations in hair growth rate and duration of the hair growth cycle

glands that are found all over the body

SEBACEOUS (oil) and ECCRINE (sweat) GLANDS

sebaceous glands secrete __________

sebum (oil that coats the hair and epidermis)

glands that secrete sweat

Eccrine and apocrine glands

this gland (found all over the body) secretes the most sweat

eccrine

this gland (found only in the pubic and axillary regions) secretes sweat

apocrine

pimples begin when..

oil gland ducts (sebaceous glands) become blocked by viscous (thick) sebum

the black part of a blackhead is caused by:

oxidized sebum

boils are caused by…

bacteria that enter a gland and invade the hypodermis

boils differ from pimples because:

boils invove hypodermis and are larger

the layer of skin that gives rise to nails is the

eponychium

the white half moon visible under the proximal part of the fingernail is the..

lunula

4 classifications of skin glands

SEBACEOUS (oil)

 ECCRINE (MEROCRINE) GLANDS (sweat)

 APOCRINE GLANDS (sweat land that produces a

secretion to coat pubic and axillary hairs, and also

produce pheromones)

oMAMMARY GLANDS (special type of

apocrine gland, but produces milk)

 CERUMINUS GLANDS (wax)

apocrine glands are found in the ________ _______ and the special protein they secrete is ______________

APOCRINE GLANDS= in the axilla and pubic

region

• they produce a secretion to coat the hairs

  • hairs function as a wick to draw the secretions to

the surface.

• also produce a type of protein called a

hormone known as PHEROMONES.

• Modified apocrine glands are also found in breast

milk ducts (mammary glands)

this gland secretes milk

mammary glands (Modified apocrine glands) secrete milk

_____________ are found in the ear, and secrete _________________

Ceruminus glands secrete wax

2 characteristics of exocrine glands

secrete substances into the cell itself

OR

onto the epidermis by way of a DUCT.

2 characteristics of endocrine glands

Endocrine glands do not have ducts

They secrete hormones directly into the blood

plasma cells secrete

a type of blood cell that secretes antibodies

Goblet Cells secrete

mucus

are goblet cells unicellular or multicellular

unicellular

Leukemia

cancer in blood-forming cells

Lymphoma

tumor developing in lymphatic tissues

Carcinoma

tumor developing in any part of the epithelium

Melanoma

tumor developing in the pigment-forming cells

(melanocytes) of the skin