Skin

Name the four organs of the INTEGUMENT

SYSTEM

Organs

a. Skin

b. Hair

c. Nails

d. Glands

What is the largest organ of THE INTEGUMENT

SYSTEM?

SKIN is the largest organ of the integument system.

Also the largest organ in the body!

What are the five Functions of the Integument

System?

Functions

a. Protection

 Abrasion

 Infections

 UV light

 Dehydration

b. Thermal regulation (maintaining proper body temp)

 Insulation = adipose layer

 Cooling = sweat glands

c. Sensory reception (touch, temp, pain, etc)

d. Vitamin D production (discussed in physiology)

e. Communication (Smile, frown, etc are forms of

communication)

What are the 3 layers of the skin?

a. EPIDERMIS

b. DERMIS

c. HYPODERMIS

What layer of the skin provides strength to the skin?

Epidermis

What layer of the skin provides protection to the

skin?

Epidermis

Which layer of the skin has no vascularization?

Epidermis

How does the epidermis get its nutrients?

It absorbs nutrients from the tissues deep to it

What layer of the skin are nails made in?

epidermis

How many layers does the epidermis have and what

are they?

10. What is the deepest layer?

11. What is the most superficial layer?

12. What layer is only present in thick skin?

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)

What are the four cell types found in the STRATUM

BASALE?

14. What protein provides waterproofing and strength to

the skin?

15. What pigment is produced in this layer?

1. Main cell type is KERATINOCYTES

Keratin is a protein, provides waterproofing and

strength to skin However, 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 are nerve fibers (sensory

receptors) for light touch

What layer has cells attached to each other by

desmosomes?

Stratum spinosum

In what layer of the epidermis do cells stop dividing?

In what layer of the epidermis do cells stop dividing?

Stratum spinosum

What are Langerhans’ cells and where are they?

White blood cells (immune function) in the stratum

spinosum of the epidermis

Where do Langerhans cells arise from?

Red bone marrow, along with other white blood cells

In what layer of the epidermis do cells start to die?

Startum granulosum

Why do most cells in the epidermis die?

Lack of nutrients because they are now too far from

nutrient source in connective tissue

The main difference between thick skin and thin skin

relates to the thickness of this layer

Stratum corneum

How long does it take for a cell to migrate from the

stratum basale to the stratum cornuem?

About 15-30 days

How long do the dead cells remain in the stratum

corneum layer before they are shed?

About 2 weeks

This layer of the epidermis is only on the palms and

soles and it is directly under the stratum corneum?

Which layer has cells that provide protection from uv

radiation?

Stratum Lucidum

What two areas separate from each other in a blister?

The stratum basale tears away from the basement

membrane

What is a vesicle?

Blister smaller than 5 mm

What is a bulla?

Blister larger than 5 mm

Why is the skin capable of repair, even after serious

damage?

Stem cells persist in both the epidermis and dermis

What are the 3 major types of Skin Cancer?

Which is most common, least common?

Which is the most deadly, least deadly?

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)

What is the major risk factor for skin cancer?

Major risk factor is UV light

Which type of cancer is most easily cured and almost

never metastasizes?

Which skin cancer is the most likely to metastasize?

BASAL CELL CARCINOMA usually doesn’t

metastasize

MELANOMA usually metastasizes

What is the medical term for a mole?

Nevus (plural = nevi)

What is the medical term for a freckle or any other

pigmented area that is flat and does not stick upwards

from the skin?

Macula

What is the medical term for scratch marks?

Excoriations

What is the medical term for dry skin?

Xerosis

What is the medical term for inflamed skin?

Dermatitis

What is Eczema?

What causes it?

What is the most frequently occurring form of

eczema?

• Itchy red skin that comes and goes.

• Caused by an autoimmune reaction.

• The most frequently occurring form of eczema

is atopic dermatitis.

Name three things that might trigger Atopic

dermatitis?

• Triggered by allergens like soaps, cosmetics,

clothing, detergents, jewelry, or sweat.

• Can be triggered by changes in weather or stress.

Touching poison ivy causes what type of skin

condition?

Contact dermatitis

What is the name for severe dandruff?

What causes it?

• Seborrheic dermatitis

• Caused by an allergy to the fungus that we all

have around our hair roots.

What is Psoriasis caused by?

An autoimmune disease of the skin

What are the symptoms of psoriasis?

silvery flakes on the elbows, knees, and scalp which are

NOT itchy

What skeletal condition is psoriasis associated with?

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

What are the two layers of the dermis?

1. PAPILLARY LAYER (Papillary = “Pimple” Has

bumps). This is the more superficial layer.

2. RETICULAR LAYER is the deeper layer

What specific layer is responsible for fingerprints,

and what layer of the skin is it in?

The PAPILLARY LAYER is in the DERMIS and is the

actual layer responsible for the fingerprints.

What is the strongest layer of the epidermis?

Stratum spinosum

What is the strongest layer of the dermis?

Reticular layer

What is the strongest layer of the skin?

epidermis

what layer of the skin is responsible for stretch marks?

dermis

Where are all the glands of the body located?

What layer of the skin is the area that a transdermal

must patch reach?

What layer of the skin generates the pink color seem

in Caucasian people?

Doctors make incisions on the body based on the

lines of cleavage of the skin. This is based on the

structure of which layer of the skin?

The DERMIS

What are Pacinian corpuscles?

nerve fibers in the reticular layer of the dermis for

vibration and pressure

What are Meissner's Corpuscles?

nerve fibers in the papillary layer of the dermis for light

touch

What are stretch marks and what causes them?

 Caused by Sudden weight gain (often seen in

pregnancy)

 During expansion of skin, collagen fibers in the

DERMIS separate = stretch marks.

What is the hypodermis?

Layer in the skin that consists of fibrous tissue, blood

vessels and nerves; sits on top of the muscles

What are 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

What cosmetic surgical procedure is performed in the

hypodermis?

Liposuction is performed in the hypodermis.

What type of tissue is cellulite?

There is no such thing as cellulite. Therefore, it is not a

type of adipose or connective tissue, and it does not

exist as a particular region of the skin.

70. What are the three types of burns?

71. Which is the most serious?

72. Which is a sunburn?

73. Which is a blister?

74. Which needs a skin graft?

Three types:

 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)

What are 2 reasons why deep burns are so

dangerous?

1)Infection

2) Dehydration: nothing to keep fluid in body.

What are DECUBITUS ULCERS

DECUBITUS ULCERS

Epidermis is destroyed, underlying tissue is

exposed.

What pigment produces brown coloration to the

skin?

MELANIN: (dark brown pigment). More melanin,

darker the skin.

What pigment accumulates more in Asian skin

types?

CAROTENE: (a yellowish/orange pigment).

Accumulates more in Asian skin types.

Why do darker-skinned people have lighter palms and

soles?

In darker-skinned people, the thick stratum lucidum

layer of the palms and soles blocks the appearance

of the melanin pigment in the deeper layers

What causes the pink color of skin in Caucasians?

HEMOGLOBIN in red blood cells is a red pigment.

Since the DERMIS is the skin layer that contains the

blood vessels, that is the layer that causes the pink skin

color of Caucasians.

What things determine skin color?

Melanin, carotene, skin thickness, and hemoglobin.

What is the medical term for a bruise?

CONTUSION: “Bruise”

What 4 things cause cyanosis?

Occurs for several reasons, including:

1) Cold

2) Not enough oxygen in body to go around. The

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.

How do wrinkles form?

Over time, 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.

86. What is BOTOX?

87. Why do people use it?

a. Why do people need repeat injections?

This is a deadly poison (botulism) which paralyses the

muscles, making them sag.

Without muscle tension, wrinkles relax.

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

come back, and need new injection.

What is one example of how a COLLAGEN

INJECTION is used for cosmetic reasons?

Collagen is 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.

Into what layer of the skin is ink injected for

TATTOOS?

Pigment is injected into the dermis.

What vitamin is produced by the skin?

Vitamin D is produced by the skin (dermis)

What is the function of Arrector Pilli?

They are tiny muscles that make the hair stick up when

you are cold, as in “goosebumps”.

92. What are destroyed by electrolysis?

93. What is hair made of?

The dermal papillae are what are destroyed by

electrolysis, so hair won’t grow back.

 Hair is just dead skin cells.

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

and the location of the melanocytes that determine hair

color?

the hair matrix

What causes differences in uncut hair length?

variations in hair growth rate and duration of the hair

growth cycle

What glands that are found all over the body?

SEBACEOUS (oil) and ECCRINE (sweat) GLANDS

What do sebaceous glands secrete?

Produce sebum (oil that coats the hair and epidermis)

What glands secrete sweat?

Eccrine and apocrine glands

Which of the above glands secretes most of the

sweat, and is found all over the body?

Eccrine

Which of the above glands only secretes sweat in the

public and axillary regions?

Apocrine

How do pimples begin?

Pimples begin when oil gland ducts (sebaceous glands)

become blocked by viscous (thick) sebum.

What is the black part of a blackhead caused by?

The black part of a blackhead is oxidized sebum

What causes boils?

Boils are caused by bacteria that enter a gland and

invade into the hypodermis.

How do boils differ from pimples?

Boils involve the hypodermis and are larger than

pimples

What layer of skin gives rise to the NAILS?

The EPIDERMIS gives rise to the nails.

What are nails made of?

Nails are made of keratin (not calcium or collagen)

What is the proximal nail fold called?

Eponychium

What is the white half-moon visible under the

proximal part of a fingernail?

lunula

What 4 classifications of SKIN GLANDS are there?

Which ones produce sweat?

 SEBACEOUS (oil)

 ECCRINE (MEROCRINE) GLANDS (sweat)

 APOCRINE GLANDS (sweat land that produces a

secretion to coat pubic and axillary hairs, and also

produce pheromones)

o MAMMARY GLANDS (special type of

apocrine gland, but produces milk)

 CERUMINUS GLANDS (wax)

110. Where are Apocrine Glands found?

111. What special protein do they secrete?

APOCRINE GLANDS are only in the axilla and pubic

region, where they produce a secretion to coat the hairs.

The hairs function as a wick to draw the secretions to

the surface.

 These glands also produce a type of protein called a

hormone known as PHEROMONES.

 Modified apocrine glands are also found in breast

milk ducts.

112. What are Mammary Glands?

a. What do they secrete?

Modified apocrine glands.

They secrete milk.

What do Ceruminus Glands secrete, and where are

they found?

Only found in the ear, and they produce wax.

What are Exocrine Glands?

Exocrine glands secrete substances into the cell itself, or

onto the epidermis by way of a DUCT.

What are Endocrine Glands?

Endocrine glands do not have ducts. They secrete

hormones directly into the blood.

What do Plasma Cells secrete?

A type of blood cell that secretes antibodies.

117. What do Goblet Cells secrete?

118. Are they unicellular or multicellular?

 Goblet cells secrete mucus.

 They are unicellular

What is Leukemia?

A cancer in blood-forming cells

What is Lymphoma?

A tumor developing in lymphatic tissues.

What is Carcinoma?

A tumor developing in any part of the epithelium

What is Melanoma?

A tumor developing in the pigment-forming cells

(melanocytes) of the skin.

What is Sarcoma?

A tumor developing in muscles and connective tissues.

What are 3 CHARACTERISTICS OF CANCER

CELLS

1. LACK DIFFERENTIATION-Normal cells have

specialized functions, but cancer cells do not

differentiate and do not contribute to the function of the

body.

2. ABNORMAL NUCLEI-They have large or multiple

nuclei with mutated chromosomes.

 3. FORM MALIGNANT TUMORS-Cancer cells

grow and divide rapidly until they accumulate and

form a lump of cancer cells called a tumor. A

BENIGN tumor is an accumulation of non-

cancerous cells because they stay in their own

capsule (encapsulated) and do not invade. If a

tumor is benign, it is not cancer.