Ch5 A&P lect

Which of the following statements about third- degree burns is INCORRECT?

-Third-degree burns are often treated with skin grafts. -Third-degree burns destroy hair follicles and nerves. -Third-degree burns burn through the epidermis, dermis, and into the subcutaneous layer. >Third-degree burns decrease perspiration, so there is no danger of dehydration.

Which of the following is a characteristic of the epidermis?

-contains fat stored in adipose tissue -is well vascularized >consists of keratinized stratified squamous epithelium -contains collagen fibers

The continual life cycle of keratinocytes being sloughed and replaced by cells undergoing mitosis takes about _________.

40-50 days

During Laura's follow-up visit for the biopsy results, her doctor recommended that she visit a dermatologist, a physician who specializes in the integumentary system. Laura has several moles, or nevi, that could be malignant melanoma. Which characteristic of the moles raised the doctor's suspicion?

A diameter the size of a dime

What does cyanosis signify?

A person has oxygen-starved skin.

What is the medical term used for baldness?

Alopecia

What stands hairs on end, causing piloerection?

Arrector pili muscle

What is the most common type of skin cancer that results in the formation of a nodule with a central "crater" that ulcerates?

Basal cell carcinoma

Which of the following characteristics is not part of the ABCDE rule?

Border regularity

Which of the following molecules is responsible for yellow-orange skin pigment?

Carotene

What modified apocrine glands secrete ear wax?

Ceruminous glands

What cells of the epidermis function as phagocytes of the immune system?

Dendritic cells

What tissue composes the reticular layer of the dermis?

Dense irregular connective tissue

Where are blood vessels housed that nourish the epidermis?

Dermal papillae

The skin surrounding Laura's wound is much warmer than the unaffected skin. Heat radiates from the infected tissue due to increased blood flow. Blood vessels, specifically capillaries, are found in which of the following layers and structures of the dermis?

Dermal papillae in the papillary layer of the dermis

What are the main components of the cutaneous membrane?

Epidermis and dermis

Which of the following sensations is not detected by the skin?

Equilibrium

Which of the following characteristics is typical of a first-degree burn?

Erythema

Which of the following cells is associated with the dermis?

Fibroblast

Which of the following structures is not found in thick skin?

Hair follicles

In which of the following locations are dead keratinized cells found?

Hair shaft

What is the main tissue of the epidermis?

Keratinized stratified squamous epithelium

What is the most numerous cell type in the epidermis?

Keratinocyte

What type of hair does a fetus have?

Lanugo

The __________ is the opaque crescent-shaped area near the proximal nail fold.

Lunula

What is the primary pigment found in skin?

Melanin

The surgical resident has examined Laura's legs and feet, and used his knowledge of skin coloration to help him make recommendations for her treatment plan. Which of the following statements is true in reference to using skin color as a diagnostic tool?

Pallor is a skin color change most easily observed in lighter skin tones in which the blood supply in the dermis has decreased to the point where the skin assumes the color of the collagen in the dermis.

Which of the following components do vellus hairs lack?

Pigment

What is the oily waxy substance secreted by sebaceous glands called?

Sebum

What stimulates the secretion of sebum?

Sex hormones

From superficial to deep, what is the correct order of the layers of the epidermis in thick skin?

Stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, and stratum basale

Which layer of the epidermis is not present in thin skin?

Stratum lucidum

Which of the following describes the effector response of sweat glands and blood vessels?

Sweat glands release sweat and blood vessels dilate.

Which type of sensory receptor in Laura's skin will respond to the doctor lightly touching her foot?

Tactile (Meissner's) corpuscles in the dermis

What are the sensory receptors in the dermal papillae that respond to light touch stimuli called?

Tactile (Meissner) corpuscles

What is the thicker, coarser, more pigmented hair found on the scalp?

Terminal hair

Why do keratinocytes in the superficial strata of the epidermis die?

They are too far away from the blood supply in the dermis.

What would happen if the eccrine sweat glands found in the skin of Laura's legs lost their blood supply?

They would no longer provide protection by producing slightly acidic secretions that deter the growth of some pathogens.

What is the primary function of melanin?

To protect the DNA of keratinocytes from mutations induced by ultraviolet (UV) radiation

What enzyme plays a major role in skin color?

Tyrosinase

Which of the following functions is not associated with the skin?

Vitamin A synthesis

What is the primary function of vitamin D?

Vitamin D is required for calcium absorption from the small intestine.

The signs of malignant melanoma are the following:

an asymmetrical shape, border irregularity, blue-black uneven coloration, a diameter generally larger than 6 millimeters, and changing shape and size.

Glands that secrete products into hair follicles are called __________.

apocrine glands

Humans often purchase antiperspirants and deodorants to suppress and mask the odors of secretions from the __________.

apocrine glands

Keratinocytes in the stratum corneum __________.

are dead and filled with keratin

The majority of cells in the epidermis arise from mitotic activity in stratum __________.

basale

The rule of nines is used to estimate the percentage of body surface area affected by __________.

burns

The bluish coloration of skin due to reduced levels of oxygen is called __________.

cyanosis

We have unique patterns on our fingers, toes, palms, and soles created by __________.

epidermal ridges

The most superficial component of the skin is the __________.

epidermis

Tommy fell and skinned his knee. The scrape did not bleed. He must have only damaged the __________.

epidermis

Part complete If you administer a subcutaneous injection, the needle will penetrate the layers in which of the following orders, starting from the skin surface? If you administer a subcutaneous injection, the needle will penetrate the layers in which of the following orders, starting from the skin surface?

epidermis, papillary layer of dermis, reticular layer of dermis, subcutaneous layer

The cuticle around a nail is the __________.

eponychium

The unique, characteristic pattern of epidermal ridges is visible as __________.

fingerprints

What type of secretion do sebaceous glands use?

holocrine secretion

If the dermis did not have dermal papillae, __________.

it would be harder to supply the epidermis with nutrients and oxygen

Squamous cell carcinoma arises from __________.

keratinocytes in stratum spinosum

What is the pigment that protects the DNA of keratinocytes from mutations induced by UV radiation?

melanin

Which of the following is NOT a skin pigment?

melanin >keratin hemoglobin carotene

The ABCDE rule is used to distinguish normal moles from ____________________.

melanomas

The nail body covers the __________.

nail bed

The __________ is the part of the nail root that contains actively dividing cells.

nail matrix

Sebum is a(n) __________.

oily mixture that lubricates skin and hair

Predict which of the following regions of the body will have predominantly thick skin.

palms

The most superficial layer of the dermis is the __________.

papillary layer

Extreme stretching of the reticular layer of the dermis results in_______________.

permanent stretch marks

An oily secretion that coats and conditions the skin and hair is secreted by the __________.

sebaceous glands

The ____________ is the largest organ in the body.

skin

The _______________ is a location of thick skin.

sole of the foot

Dividing stem cells that give rise to keratinocytes are located in the __________.

stratum basale

Where are melanocytes located?

stratum basale of the epidermis

The most superficial layer of the epidermis is called the __________.

stratum corneum

What is the thickest layer of the epidermis?

stratum spinosum

Eccrine glands produce __________.

sweat containing mostly water

Mammary glands are specialized __________.

sweat glands

Skin without keratin would be more likely to __________.

tear upon being mechanically stressed

A second-degree burn damages the epidermis and parts of the dermis and causes pain, blistering, and possibly scarring.

true

The reticular layer is the deeper layer of dermis and is composed mainly of dense irregular connective tissue.

true

Melanin is produced upon exposure to __________.

ultraviolet (UV) radiation

Which of the following is NOT one of the functions of the integumentary system?

vitamin C synthesis