Ch.3: Skin Structures & Growth Practice Flashcards

Comprehensive practice questions covering Ch.3 Skin Structures & Growth, including the layers of the epidermis, dermis, nerve fibers, pigmentation, and skin functions.

What is the definition of dermatology?

The study of skin, its nature, structure, diseases, functions, and treatment.

According to the notes, what are the characteristics of healthy skin?

Healthy skin is free of any visible signs of disease, infection, or injury; it is $50$ to $70$ percent water, slightly moist, soft, smooth, and slightly acidic.

What are the three main components of the skin?

The epidermis, dermis, and subcutaneous layer.

How is the Epidermis described in the transcript?

The outermost and thinnest layer of the skin which contains no blood vessels and is made of five layers called Strata.

What is the Stratum Corneum (Horny layer)?

The layer we see when looking at the skin, made of Keratin, a fibrous protein which is the principal component for hair, skin, and nails.

Where is the Stratum lucidum located and what are its characteristics?

It is a clear, translucent layer under the Stratum Corneum consisting of small cells which light can pass through; it is located on the palms, soles, and digits.

What occurs in the Stratum Granulosum?

It is composed of cells that look like granules filled with keratin; cells die here as they are pushed to replace dead cells shed from the Stratum Corneum.

What are the unique features of the Stratum Spinosum?

It is known as the spiny layer, located above the stratum germinativum, where skin cell shedding begins; it is the largest layer of the epidermis.

What is the function of the Stratum Germinativum (Basal cell layer)?

It is the deepest layer where new skin cells and the growth of the epidermis originate; it contains Melanocytes which produce the skin pigment melanin.

What structures are found within the Dermis?

Blood vessels, lymph vessels, nerves, sudoriferous (sweat) glands, sebaceous (oil) glands, hair follicles, and arrector pili muscles.

Identify the two layers of the Dermis and their locations.

The Papillary layer is the outer superficial layer beneath the epidermis, and the Reticular layer is the deepest layer that supplies the skin with $O_2$ and nutrients.

What is the function of the Arrector Pili Muscles?

These are small involuntary muscles attached diagonally to the side of the hair follicle that cause "goose bumps."

What are the functions of Subcutaneous Tissue?

This fatty tissue below the dermis gives the body smoothness and contour, contains fat for energy, and acts as a protective cushion for the skin.

Explain the role of Motor Nerve Fibers.

They convey impulses from the brain or spinal cord to the muscles or glands to stimulate muscles.

What is the function of Secretory Nerve Fibers?

These are motor nerves attached to sweat and oil glands that regulate excretion from sweat glands and control sebum output.

What sensations do Sensory Nerve Fibers react to?

They send messages to the central nervous system and brain to react to heat, cold, touch, pressure, and pain.

What are the two types of Melanin and their characteristics?

Pheomelanin (red to yellow tones; rosy skin with red or neutral hair) and Eumelanin (dark brown to black; cooler hair and skin tones).

What SPF is recommended for Broad Spectrum Sunscreen to help melanin protect the skin?

An spf of $15$ or higher.

Contrast Collagen and Elastin.

Collagen is fibrous connective tissue that gives the skin form and strength; Elastin is a protein base that forms elastic tissue interwoven with collagen to provide flexibility and elasticity.

Compare the functions of Sudoriferous and Sebaceous Glands.

Sudoriferous glands excrete sweat to detoxify the body and regulate temperature; Sebaceous glands are connected to hair follicles and secrete Sebum to lubricate skin and preserve hair softness.

List the six principal functions of the skin.

1) Protection, 2) Sensation, 3) Heat Regulation, 4) Excretion, 5) Secretion, and 6) Absorption.

What specific temperature is mentioned regarding Heat Regulation?

$$98.6^{\circ}F$$