a&p ch.7 slides

Which skin region consists of epithelial tissue?

Epidermis

The layer deep to the skin that anchors it to underlying muscles is the

Hypodermis

What tissue type primarily makes up the hypodermis?

Adipose tissue

The epidermis is vascularized.

False

Order the epidermal strata from deepest to most superficial:

Stratum basale; Stratum spinosum; Stratum granulosum; Stratum lucidum; Stratum corneum

The protein that gives skin its protective properties is

Keratin

What is the function of tactile (Merkel) cells?

Sensory receptors for touch

Which epidermal cells function as macrophages to activate the immune system?

Dendritic cells

What is the most abundant cell type in the epidermis?

Keratinocytes

Which layer is also known as the stratum germinativum?

Stratum basale

How long does it take for a cell to travel from the basal layer to the surface?

25-45 days

The stratum corneum consists of living, nucleated cells.

False

In which layer does active mitosis occur?

Stratum basale

Which layer of the epidermis is found only in thick skin?

Stratum lucidum

What are the two distinct regions of the skin?

Epidermis and dermis

What structures tightly connect keratinocytes together?

Desmosomes

Controlled cell death that occurs as cells move to the surface is called

Apoptosis

Where is thick skin typically found?

Hands and feet

What percentage of the epidermal thickness is accounted for by the stratum corneum?

Three-quarters

What granules in the stratum granulosum help prevent water loss?

Lamellar granules

The process where cells fill with protein and disintegrate their nuclei is

Keratinization

What are the 'prickle cells' found in the stratum spinosum?

Keratinocytes

What are the fingerlike projections of the dermis into the epidermis?

Dermal papillae

What tissue makes up the reticular layer?

Dense irregular connective tissue

What tissue makes up the papillary layer?

Areolar connective tissue

What are the two layers of the dermis?

Papillary and reticular

What is the deepest layer of the epidermis?

Stratum basale

Which layer contains a weblike system of intermediate pre-keratin filaments?

Stratum spinosum

Where are melanosomes transferred to protect the nucleus from UV?

Keratinocytes

What sensory receptors are found in the dermal papillae?

Tactile corpuscles

What are dermal folds found near joints?

Flexure lines

Which dermal layer contains the cutaneous plexus?

Reticular layer

What is a fluid-filled pocket that separates epidermal and dermal layers?

Blister

What is the term for 'stretch marks'?

Striae

What causes cleavage (tension) lines in the dermis?

Parallel collagen fibers

What structures in the dermis contribute to fingerprints?

Friction ridges

What condition causes blue skin due to low oxygen?

Cyanosis

What color does hemoglobin impart to fair skin?

Pinkish hue

Where does carotene primarily accumulate?

Stratum corneum and hypodermis

What enzyme is required to produce melanin?

Tyrosinase

Melanin is produced from which amino acid?

Tyrosine

What pigment is only actually made in the skin?

Melanin

The hypodermis is considered part of the skin.

False

What is the oily secretion of sebaceous glands called?

Sebum

Which type of gland produces earwax?

Ceruminous glands

What causes odor with apocrine sweat?

Bacterial breakdown

Where are apocrine sweat glands primarily located?

Axillary and genital areas

Which sweat glands are most numerous and used for thermoregulation?

Eccrine glands

What is the term for 'bruises'?

Ecchymoses

A yellow skin cast usually indicates a disorder of which organ?

Liver

What are the three parts of the hair shaft?

Medulla, cortex, cuticle

What type of keratin is found in hair and nails?

Hard keratin

What is the term for 'cradle cap' in infants?

Seborrhea

What are modified apocrine glands that secrete milk called?

Mammary glands

What is the primary function of sebum?

Soften hair and skin

What stimulates sebaceous glands at puberty?

Androgens

Sebaceous glands are found on palms and soles.

False

What percentage of total blood volume can the skin hold?

5%

What is the actively dividing area of the hair bulb?

Hair matrix

What is the area of the hair within the scalp?

Root

Which hair pigment is found in red hair?

Pheomelanin

What are Beau's lines?

Horizontal lines across nails

What do 'spoon nails' (koilonychia) potentially indicate?

Iron deficiency

What is the white, crescent-shaped area of the nail?

Lunule

What is the 'acid mantle' of the skin?

Low pH surface

What is the coarse, long hair of the eyebrows and scalp?

Terminal hair

What is the term for hair thinning after age 40?

Alopecia

What is the pale, fine body hair of children?

Vellus hair

Which muscle is responsible for 'goose bumps'?

Arrector pili

What is the function of the chemical barrier provided by melanin?

Shield DNA from UV

Which nitrogenous wastes are secreted in limited amounts by the skin?

Ammonia, urea, uric acid

What is the most common and least malignant skin cancer?

Basal cell carcinoma

What enzyme does the skin make to prevent wrinkles?

Collagenase

Which substances can penetrate the skin's physical barrier?

Lipid-soluble substances

How does the skin respond to a cold environment?

Dermal blood vessels constrict

What is 'insensible perspiration'?

Unnoticeable sweat (500 ml/day)

What vitamin is synthesized by the skin using sunlight?

Vitamin D

Which cells provide a biological barrier by engulfing invaders?

Dendritic cells

What hormone is associated with male pattern baldness?

DHT

What is acne?

Inflammation of sebaceous glands

What does the 'E' stand for in the ABCDE rule?

Evolving

What is the primary risk factor for skin cancer?

UV radiation exposure

What is the condition of depigmented skin patches?

Vitiligo

What is the genetic inability to produce melanin?

Albinism

What diameter size is a warning sign for melanoma?

Larger than 6 mm

A in ABCD rule for melanoma

Asymmetry

B in ABCD rule for melanoma

Border irregularity

C in ABCD rule for melanoma

Color

D in ABCD rule for melanoma

Diameter

What is the most dangerous type of skin cancer?

Melanoma

Which skin cancer involves the keratinocytes of the stratum spinosum?

Squamous cell carcinoma

What is another name for the eponychium?

Cuticle

What part of the nail is responsible for growth?

Nail matrix

Why is a third-degree burn not painful?

Nerve endings are destroyed

Which burn degree is characterized by blisters?

Second-degree

Which burn degree involves only the epidermis?

First-degree

Most skin tumors are benign.

True

What is a blackhead?

Oxidized blocked sebaceous gland

What are first- and second-degree burns collectively called?

Partial-thickness burns

When is a burn considered critical?

25% second-degree; 10% third-degree; Third-degree on face/hands/feet