Integumentary System

What is the primary function of the epidermis?

Protection from water, air, infection, chemicals, and UV radiation.

What sensations does the epidermis provide?

Sensations such as pressure, heat, cold, and pain.

How does the epidermis regulate temperature?

Through sweat and blood flow near the surface.

What is produced by the epidermis that is essential for health?

Vitamin D.

What type of tissue makes up the epidermis?

Stratified squamous epithelial tissue.

What is the stratum corneum?

The outermost layer of the epidermis composed of dead, keratinized cells.

Where is the stratum lucidum found?

Only on the palms of the hands and soles of the feet.

What happens to cells in the stratum granulosum?

Cells begin to flatten and disintegrate.

What is the role of melanocytes in the epidermis?

They produce melanin, which gives skin its color and protects against UV radiation.

How do melanocytes differ in dark-skinned and light-skinned individuals?

They produce the same amount of melanin, but dark-skinned individuals have melanin that is more effective.

What type of skin cancer is associated with uncontrolled division of melanocytes?

Melanoma.

What are the two layers of the dermis?

The papillary layer and the reticular layer.

What is the function of dermal papillae?

They create fingerprints and increase friction for gripping objects.

What is the hypodermis also known as?

The subcutaneous layer.

What is the composition of the hypodermis?

Loose, fatty connective tissue that connects the skin to muscle or bone.

What are the two types of sudoriferous glands?

Eccrine (merocrine) and apocrine glands.

Where are eccrine sweat glands found?

All over the body, including feet, back, chest, forehead, and palms.

What is sebum and its function?

Sebum is an oily substance produced by sebaceous glands that lubricates skin and hair and kills bacteria.

What are the four basic parts of a nail?

Free edge, nail body, root, and nail matrix.

What is the function of the eponychium (cuticle)?

It provides a protective seal for the nail matrix.

What causes lines of cleavage in the skin?

The arrangement of collagen fibers in the dermis.

Why are lines of cleavage important for surgeons?

Cuts should be made parallel to the lines of cleavage to minimize scarring.

What happens to the skin when blood vessels in the dermis swell?

The skin appears red as heat from the blood dissipates.

What can happen if blood supply to the skin is restricted for a prolonged time?

Decubitus ulcers (bedsores) can form.

What is the role of hair on the body?

It keeps heat in, protects from the sun, alerts to insects, and prevents entry of objects.

What is the hair follicle?

The root of the hair located within the dermis where hair cells divide.

What is the function of arrector pili muscles?

They make hair stand on end.