BSC 215 Chapter 5

Actively dividing cells in a nail are found in the

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

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

vitamin C synthesis: The skin plays a role in the synthesis of vitamin D, not vitamin C. Return to Assignment

he dermal papillae are labeled

A. The dermal papillae house tiny blood vessels where oxygen and nutrients diffuse into the extracellular fluid of the dermis and up into the cells of the avascular epidermis.

Max and Breanna go to the beach, and Max tells Breanna that she does not need sunscreen because she is African American and individuals with dark skin cannot get sunburns or skin cancer. What should Breanna tell him in response?

Breanna should inform Max that people with darker skin are still susceptible to both sunburns and skin cancer

You are a researcher for a cosmetics company, and the company wants you to devise a product that makes eyelashes grow longer. How could this be achieved?

By increasing the rate of mitotic division of keratinocytes: Prolonging the phase of growth stage will allow keratinocytes to keep dividing and pushing the older keratinocytes superficially.

The reticular layer of the dermis is labeled

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

While woodworking, your friend Lily cuts her forearm with a saw. You examine the wound and see large quantities of adipose tissue at its base. Her wound extends down to the

Deeper than the cutaneous membrane

Vitiligo is a condition characterized by death or dysfunction of scattered groups of melanocytes in the skin. How might vitiligo cause the skin to appear?

It may cause dark patches along with lighter patches.

A hypothetical drug causes blood vessels to grow from the dermis into the superficial stratum granulosum of the epidermis. What effect would you see in the most superficial epidermal layers?

It will thicken the epidermis.

Paper cuts often involve only the epidermis. You may get a paper cut and notice that it doesn't bleed, but you can still feel it. Why can you feel it but the cut isn't bleeding?

Merkel cells are found in the stratum basale and the cut is not extensive enough to reach the dermis.

Which of the following is a true statement?

Products with amino acids for hair and nails could affect future hair and nail growth: These products may affect hair and nails during the growth stage.

Lily gets a wound that is located on her left anterior forearm and cuts straight across the width of her arm. Select the correct statement.

Scarring may occur because the cut runs perpendicular to the tension lines.

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

Stratum basale

In which layer of the epidermis are stem cells located?

Stratum basale

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

Sweat glands release sweat and blood vessels dilate: In response to increase in body temperature, sweat glands will release sweat for evaporative cooling and blood vessels will dilate so that heat can dissipate.

Predict what would happen to the cells of the epidermis if blood vessels in the dermis constricted and decreased blood flow for several hours.

The cells of the epidermis will reduce activity and potentially die: Cells of the epidermis do not get adequate nutrient/waste exchange.

A hypothetical poison prevents oxygen from binding to hemoglobin. How would this affect skin color in a fair-skinned person?

The skin would appear to have a faint bluish tint.

Burn victims often suffer damage to large portions of the integument. Predict the complications these patients may develop.

There may be increased activity in damaged nerves: Imagine how there would be a prolonged pain sensation. This is due to damaged tissue that surrounds or include damaged nerves that send signals of pain.

Glands that release sweat into hair follicles are called

apocrine sweat glands: The secretions from apocrine glands are metabolized by microbes and create a characteristic odor.

Keratinocytes in the stratum corneum

are dead and filled with keratin

In order, from deep to superficial, what are the five strata of the epidermis?

basale, spinosum, granulosum, lucidum, corneum

The epidermis receives nutrients and oxygen from:

capillary networks in the dermis: The avascular epidermis receives nutrients and oxygen by diffusion from the dermis, an example of the gradients core principle. This limits how thick the epidermis can be.

Which of the following best describes holocrine gland secretion?

cell rupture and die to secrete their product: In holocrine secretion, secretory cells accumulate their product in the cytosol, which is released when the cell ruptures and dies

A surgical incision along tension lines

closes and heals with relatively little scarring: If a skin wound is parallel to the tension or cleavage lines, its edges tend to stay closed and heal better, with less risk of scarring.

Which of the following is a characteristic of the epidermis?

consists of keratinized stratified squamous epithelium: major cells being the keratinocyte.

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

cyanosis: Skin may appear cyanotic when an individual has breathing difficulties, when hemoglobin and red blood cell levels are too low, or when hemoglobin is unable to bind to oxygen.

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: Subcutaneous injections are common because the subcutaneous layer or hypodermis is highly vascularized.

The most superficial layer of the cutaneous membrane is called the

epidermis: consists of keratinized stratified squamous epithelium that rests on top of a basement membrane.

The unique, characteristic pattern of epidermal ridges is visible as

fingerprints

Hair growth occurs at the

hair root: hair growth occurs in the matrix of the hair root

Which of the following molecules turns orange red when oxidized?

hemoglobin

Which of the following will most likely cause a greasier scalp and dandruff?

increased testosterone:

If the dermis did not have dermal papillae,

it would be harder to supply the epidermis with nutrients and oxygen: Dermal papillae contain capillaries that supply the epidermis with nutrients and oxygen by diffusion.

Which of the following is NOT a skin pigment?

keratin

Which type of tissue makes up the outermost cutaneous membrane of your body?

keratinized stratified squamous epithelium: The outermost cutaneous membrane is the epidermis, which is composed of keratinized stratified squamous epithelium.

The most numerous cells of the epidermis are the

keratinocytes

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

melanin

The large cell in the middle of a keratinocyte is a

melanocyte: Melanocytes are cells located in the stratum basale that produce the protein melanin. A melanocyte resembles an octopus, with numerous "arms" that reach out and contact keratinocytes.

This is an example of

merocrine secretion

Sebum is a(n)

oily mixture that lubricates skin and hair: Sebum also has antimicrobial properties to protect the skin from infections.

If an infant consumes too much carotene from baby food, her skin might turn

orange

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

palms

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

sebaceous glands: Sebaceous glands produce sebum—a waxy, oily mixture consisting largely of various lipids—and secrete it via holocrine secretion.

This gland produces an oily secretion called

sebum: Sebaceous glands produce sebum, a waxy, oily mixture consisting largely of various lipids and secrete it via holocrine secretion.

The blue lines on this figure are called

tension lines: Tension or cleavage lines form because of gaps between the bundles of collagen that indent the epidermis. Tension lines normally run in a circular pattern in the neck and trunk, but run longitudinally in the head and upper and lower limbs.

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

terminal hair: We find terminal hair on the scalp, around the eyes, and after sexual maturation in the armpits and genital area.