Ch 5: The Integumentary System

BIOL 2301 - Margarita Bracamonte - HCCS

What are the two parts of the integumentary system?

1. Cutaneous membrane

2. Accessory structures

What is another name for a cutaneous membrane?

Skin.

What are the accessory structures?

Hair, nails, and glands.

What are the two layers of skin?

1. Epidermis

2. Dermis

What are the functions of the skin?

• Physical protection from the enviornment

• Excretion of wastes

• Regulation of body temperature

• Prevention of water loss

• Prevention of pathogen entry

• Detection of touch, pressure, pain, and temperature

What type of tissue makes up epidermis?

Keratinized stratified squamous epithelial tissue.

What is the function of the epidermis?

Protection against microorganism entry, loss of water, and maintaining body temperature.

Is epidermis vascular or avascular? How do you know?

Avascular, it is made up of epitheial tissue.

What are the layers of the epidermis in order from superficial to deep?

1. Stratum corneum

2. Stratum lucidum (can be missing)

3. Stratum granulosum

4. Stratum spinosum

5. Stratum basale

When is the stratum lucidum missing?

In thin skin.

Where is thick skin found?

The feet and the palms.

How many layers of epidermis are in thick skin?

Five.

Is the stratum corneum thick or thin in thick skin?

Very thick.

What is not found in thick skin that is found in thin skin?

Hair follicles, apocrine sweat glands, and sebaceous glands.

Where can thin skin be found?

Everywhere in the body except for the palms and the feet.

How many epidermis layers are in thin skin?

Four.

Is the stratum corneum thick or thin in thin skin?

Thin.

What is not found in thin skin that is found in thick skin?

Hair follicles, apocrine sweat glands, and sebaceous glands.

What is the stratum corneum?

The top most layer of the skin.

What is the stratum corneum made up of?

About 15-30 layers of dead keratinocytes.

What is the function of the stratum corneum?

Resists water loss and protects from abrasion and penetration of microorganisms.

What are keratinocytes?

Cells in the skin that are filled with a hydrophobic protein called keratin that provides protection from UV rays, pathogens, radiation, waterloss, etc.

What is the stratum basale?

The bottom layer of the epidermis that attaches to the basement membrane, separating the epidermis to the dermis.

What is the stratum basale made up of?

A layer of cuboidal/low columnar st3em cells that form keratinocytes.

What does skin pigment come from?

Pigments like carotene and melanin as well as blood circulation in the dermis.

What color is carotene?

Orange-yellow.

What foods contain carotene?

Carrots, corn, squash.

What happens if one eats too much carotene?

Their skin would turn orange.

What color is melanin?

Brown-black.

What is melanin made from?

Melanocytes.

Where are melanocytes found?

The stratum basale of the epidermis.

What are the two functions of melanin?

1. Skin color

2. UV ray protection

How does melanin relate to a persons skin color?

The more melanin a person has, the darker the skin color and vise versa.

What is the difference between melanin and melanocytes in terms of skin color?

Melanocytes create melanin but do not in themselves pigment the skin.

How does melanin relate to UV ray protection?

The more melanin a person has, the more protection they have and vise versa.

Where does blood circulate in the skin?

The dermis.

What color is oxygenated blood?

Bright-red.

What happens to the skin in the heat?

Blood vessels in the dermis dialate causing the skin to redden.

What happens when blood flow in the dermis decreases?

The skin becomes pale.

What is jaundice?

The yellowing of the skin caused by liver disease like cancer or hepatitis.

What is vitiligo?

An autoimmune disorder that attacks melanocytes and limits their melanin production in certain spots.

What does vitiligo skin look like?

Has white patches.

What is cyanosis?

A lack of blood flow to the skin causing it to appear blue.

What is albinism?

A genetic recessive disorder that lacks enzymes that allow for melanocytes to make melanin.

What color is al1bino skin?

White/without pigment.

What type of tissue is the dermis made out of?

Connective tissue.

Is the epidermis superior or inferior to the dermis?

Superior.

Is the dermis superior or inferior to the dermis?

Inferior.

What structures are found in the dermis? Blood vessels

sweat/oil glands

What are the two major regions of the dermis in order from top to bottom? 1. Papillary layer 2. Reticular layer

What is the papillary layer of the dermis made out of?

Areolar connective tissue.

What is the thickness of the papillary layer of the dermis?

Thin.

What does the papillary layer of the dermis contain?

Many blood vessels

What are phagocytes?

A type of white blood cell that helps fight pathogens.

What is the reticular layer of the dermis made out of?

Dense irregular connective tissue.

What is the thickness of the reticular layer of the dermis?

Thick.

What does the papillary layer of the dermis contain?

Most other parts of the skin like the sweat/oil glands

What are collagen used for in the skin?

Use to keep the elasticity

What can be used to increase collagen in the skin?

Topicals and injections.

What do collagen fibers form?

Net-like networks.

What is the hypodermis?

A layer of tissue under the skin.

What is the hypodermis made out of?

Mainly adipose connective tissue.

What is another name for the hypodermis?

Subcutaneous membrane.

What is subcutaneous fat?

Another name for the adipose tissue that is in the hypodermis since it is mostly made up of fat.

Is the hypodermis a layer of skin?

No.

How much of the human body is made up of subcutaneous fat?

80%.

What are the functions of the hypodermis?

Bind the skin to the underlying tissues

Why is medicine given with a hypodermic injection?

The layer is supervascular so it has many arteries slash veins that supply blood to the dermis.

What contributes to the rise of skin cancer?

The deteriorating ozone layer and the societal want to be tan like in tanning beds.

What are the three types of skin cancer?

1. Basal cell carcinoma

2. Squamous cell carcinoma

3. Melanoma.

Is skin cancer common?

Yes

Is skin cancer treatable?

they usually are if caught early enough.

What is the most common kind of skin cancer?

Basal cell carcinoma.

Where does basal cell carcinoma start?

In the stratum basal of the epidermis.

What are the main causes of basal cell carcinoma?

UV rays and wounds from open sores

What is the best kind of treatment for basal cell carcinoma? What are the other options?

The best is surgery

What is the second most common type of skin cancer?

Squamous cell carcinoma.

What layers of the epidermis does squamous cell carcinoma affect?

Statum spinosum.

What does squamous cell carcinoma present itself as?

Lesions

What is the usual treatment for squamous cell carcinoma?

Surgery or radiation as it is precancerous.

What is the most dangerous form of skin cancer?

Melanoma.

Why is melanoma the most dangerous kind of skin cancer?

It is highly metastatic.

Which cell in the skin becomes cancerous that causes melanoma?

Melanocytes.

What does melanoma usually develop from?

A mole.

How does melanoma appear in the skin?

As black patches with uneven orders that are raised.

What is the usual treatment for melanoma?

Surgical cell extraction/excision and immunotherapy.

What is the ABCDE mnemonic for?

A way to detect early stage melanoma.

What does the A in the ABCDE mnemonic stand for?

Asymmetry - the two sides of a mole are not symmetrical.

What does the B in the ABCDE mnemonic stand for?

Borders - the edges are irregular in shape.

What does the C in the ABCDE mnemonic stand for?

Color - it is varried shades of black/brown.

What does the D in the ABCDE mnemonic stand for?

Diameter - it is larger than 6mm.

What does the E in the ABCDE mnemonic stand for?

Evolution - it is changing shape over time.

What can cause burns in the skin?

Intense heat

What serious threats can occur to a burned person?

Dehydration

How are burns classified?

By depth of tissue injured.

What are the four classifications of burns according to depth or severity?

First-degree burns

Which layers of the skin are involved in a first-degree burn?

Only the epidermis.

What are the signs of A first-degree burn?

Pain

What is an example of a first-degree burn?

A mild sunburn.

How do first-degree burns typically heal?

Typically by themselves with moisturizing.