Intergumentary System

Name the 3 layers of the skin

"Epidermis, Dermis, Hypodermis"

What is the epidermis?

The outermost layer of the skin.

What is the epidermis made of?

Stratified squamous epithelial cells.

What does keratinocytes help with in the skin?

Provide protection and waterproofing.

Describe the functions of the epidermis:

"Protection, barrier against pathogens, UV radiation protection, and water loss prevention."

What is the most abundant cell type in the epidermis?

Keratinocytes.

How many layers are in the epidermis?

4-5 layers.

Name the layers of the epidermis:

"Stratum corneum, Stratum lucidum (in thick skin), Stratum granulosum, Stratum spinosum and Stratum basale"

What is the stratum corneum?

The outermost layer of dead keratinized cells.

What is stratum lucidum?

"A clear, thin layer found only in thick skin (e.g., palms, soles)."

Where is stratum lucidum found on the body?

Palms of the hands and soles of the feet.

What is the stratum granulosum?

A layer where keratinocytes begin to die and form granules.

What is the stratum spinosum?

A layer with spiny-shaped cells providing strength and flexibility.

What is stratum basale?

The deepest layer where new cells are produced.

Where are melanocytes found?

In the stratum basale.

What do melanocytes produce and help with?

Produce melanin; help with skin pigmentation and UV protection.

Where are the two places that Merkel cells are found?

Stratum basale and hair follicles.

What are Merkel cells?

Sensory cells for touch.

What is the dermis?

"The middle layer of the skin containing connective tissue, blood vessels, and nerves."

Name the two layers of the dermis:

Papillary layer and Reticular layer

What does the dermis help the skin do?

"Provide strength, elasticity, and nourishment."

What does the papillary layer do?

Provides nutrients and contains sensory receptors.

What does the reticular layer do?

Provides structure and elasticity with collagen and elastin fibers.

Which layer of the skin is thicker and thinner?

Dermis is thicker; epidermis is thinner.

Where is fibroblast located?

In the dermis.

What does fibroblast produce?

Collagen and elastin fibers.

What do collagen and elastin fibers provide to the skin?

Strength and elasticity.

What is the hypodermis?

The deepest layer of the skin containing fat and connective tissue.

How does hypodermis help the skin?

"Insulation, energy storage, and shock absorption."

What tissue is found in the hypodermis?

Adipose tissue.

What is adipose tissue used for in the hypodermis?

Fat storage and insulation.

Where are the sweat glands located?

In the dermis and hypodermis.

What does sweat contain?

"Water, salts, and waste products."

What do sweat glands help do?

Regulate body temperature through perspiration.

Where are the sebaceous glands?

Attached to hair follicles in the dermis.

What do sebaceous glands produce?

Sebum.

What is sebum?

An oily substance that lubricates and waterproofs the skin and hair.

Where are nerve endings located?

In the dermis and epidermis.

What are nerve endings also known as?

Sensory receptors.

What are nails made of?

Keratin.

Where is mitosis found?

In the stratum basale of the epidermis.

What does mitosis produce?

New skin cells.

What type of connective tissues does the hypodermis have?

Loose connective tissue and adipose tissue.

What does the connective tissue do for the hypodermis?

Provides insulation and cushioning.

What type of connective tissue does the dermis have?

Dense irregular connective tissue.

What does the connective tissue do for the dermis?

Provides strength and elasticity.

What is epithelial tissue?

Tissue that forms the outer layer of the skin and lines body cavities.

What are dermal papillae?

Projections of the dermis that interlock with the epidermis.

Where are hair follicles located?

In the dermis.

What is atrophied?

Decreased in size or wasting away of tissue.

Where are nerve fibers and blood vessels located?

In the dermis.

What are nerve fibers and blood vessels located?

Provide sensation and nourishment to the skin.