Chapter 4: Skin and Body Membranes

The membrane shown in Figure 4.2 is a ________. (pointing to lung)

pleura, a serous membrane

Which of the following kills bacteria and prevents bacterial invasions of the skin?

sebum

The type of burn that involves injury to the epidermis and the upper region of the dermis and is red, blistered, and painful is termed as a ________-degree burn.

second

The pleura and pericardium are examples of ________ membranes that cover organs in a body cavity closed to the exterior.

serous

Which membrane is constructed of a visceral and parietal layer?

serous

The part of a hair that projects from the surface of the scalp or skin is called the ________.

shaft

Dermatitis

skin inflammation

Impetigo

staphylococcus bacterial infection causing water-filled lesions, commonly around the mouth and nose

The epidermis is composed of ________.

stratified squamous epithelium

A splinter penetrates to the deepest layer of the epidermis on your foot. This layer is the ________.

stratum basale

The layer of the epidermis in which cells die because of their inability to get nutrients and oxygen is the clear layer called ________.

stratum lucidum

Jan got her microscope slides mixed up in lab as they were unlabeled. The slide with abundant adipose tissue should be labeled as the ________.

subcutaneous tissue

The ________ membrane lines the fibrous capsule surrounding joints.

synovial

Which of the following is a connective tissue membrane?

synovial membrane

In order to warm the body up when cold ________.

the arrector pili muscles contract to stand hairs upright

A physician estimates the volume of fluid lost in a severely burned patient by ________.

using the "rule of nines"

The white, cheesy-looking substance that is produced by the sebaceous glands and protects a baby's skin while it is floating in its water-filled sac inside the mother is called ________.

vernix caseosa

Herpes simplex

virus that produces cold sores

The layer of the serous membrane that covers an organ is known as the ________ layer.

visceral

he deepest layer of the serous membrane covering the outer surface of the heart is the ________.

visceral pericardium

Which vitamin is synthesized by the skin?

vitamin D

A needle pierces through the epidermal layers of the forearm in the following order: 1. stratum basale 2. stratum corneum 3. stratum granulosum 4. stratum lucidum 5. stratum spinosum

2, 3, 5, 1, 4

Stratum basale

Deepest layer of the epidermis that is situated closest to the dermis

Which of the following is a vital function of the skin?

It converts modified epidermal cholesterol to vitamin D.

Which of the following is an indication of melanoma?

a pigmented spot that contains areas of different colors

The outermost layer of the epidermis is keratinized and known as stratum ________.

corneum

The only dry membrane is the ________.

cutaneous membrane

Nutrients reach the surface of the skin (epidermis) through the process of ________.

diffusion

Dandruff

dry, dead flakes of stratum corneum

The type of gland responsible for body temperature regulation is the ________ gland.

eccrine (sweat or sudoriferous)

The two main layers of skin are ________.

epidermis and dermis

The sebaceous and sweat glands associated with the skin are classified as ________ glands because they release secretions to the skin's surface via ducts.

exocrine

Third-degree, or full-thickness, burn

full thickness burn of the skin in which the skin becomes blackened or blanched (gray-white)

The Staphylococcus infection of the skin that causes pink, water-filled, raised lesions is known as ________.

impetigo

Synovial fluid reduces friction ________.

in movable joints such as the knee

Acne

infection of the sebaceous gland and the formation of pimples

Boils and carbuncles

inflammation of hair follicles and sebaceous glands

The skin and its derivatives (nails, glands, and hairs) form the ________.

integumentary system

Which of the following abnormal skin colors results from liver disorders?

jaundice

Although you get wet while swimming, a tough protein within the skin prevents it from soaking up moisture like a sponge. This substance is ________.

keratin

Nails are composed of ________.

keratin

Where are mucous membranes found?

lining the inside of the stomach

The white crescent area located over the nail matrix is called the ________.

lunule

Basal cell carcinoma

malignancy of the lowest epidermal layer

Hair color is due to a pigment known as ________.

melanin

The "tanning" effect (darkening of the skin) that occurs when a person is exposed to the sun is due to ________.

melanin

The three pigments that contribute to skin color are ________, ________, and ________.

melanin; carotene; hemoglobin

What skin disorder is recognized using the ABCD rule?

melanoma

The secretions of the eccrine glands are ________.

mostly water, sodium chloride, and trace amounts of wastes, lactic acid, and vitamin C

Fingerprints and footprints in the epidermis are created by dermal papillae present in the ________.

papillary layer of the dermis

Which of the following letters in the ABCD rule for recognizing melanomas is incorrect?

D stands for diagnosis

A genetic switch turns on male pattern baldness in response to ________.

Age

Julia works in a walk-in clinic where several patients arrive with sunburns. How should she distinguish the first-degree and second-degree burns from one another?

Although both first-degree and second-degree burns produce red and painful skin and are partial thickness burns, only the second-degree burns produce blisters.

Keratinocyte

Cell commonly found in the epidermis that produces keratin

Epidermal dendritic cell

Cell responsible for alerting and activating an immune response to a bacterial or viral invasion

Melanocyte

Cell that produces a pigment known as melanin

Distinguish between the locations and secretions of apocrine and eccrine sweat glands.

Eccrine sweat glands are more numerous than apocrine sweat glands; they are found all over the body. Eccrine sweat glands function in body temperature regulation. When we are too hot, eccrine sweat glands release sweat containing water, salts, vitamin C, and metabolic wastes on to the body's surface. Upon its evaporation, we are cooled down. The ducts of apocrine sweat glands empty into hair follicles in the axillary and genital areas. Apocrine sweat glands activate at puberty and produce sweat almost continuously, but their overall function is not know. Apocrine sweat is milky or yellowish in color due to fatty acids and proteins in the secretions.

Collagen and elastic fibers are common in the epidermis of the skin.

FALSE

Joe just burned his hand on a hot pot. A blister forms and the burn is painful; Joe's burn would best be described as a third-degree, or full-thickness, burn.

FALSE

Milia is most common during old age when secretions accumulate in the sebaceous glands.

FALSE

Sebaceous glands may be classified as eccrine or apocrine depending on their locations.

FALSE

Serous membranes line and lubricate joint cavities such as the knee.

FALSE

The ABCD rule is used for classifying burns.

FALSE

The reason that the nail bed appears pink is the presence of a large number of melanocytes in the underlying dermis.

FALSE

When an individual is exposed to extremely low air temperatures, the capillaries of the skin will dilate so that blood will flush into skin capillary beds and heat will be dissipated.

FALSE

Sebaceous glands release sweat to help control body temperature.

False

Subcutaneous tissue

Hypodermis

Explain three ways in which the skin protects deeper tissues from mechanical damage. Answer:

Keratinocytes are the most common cell type in the epidermis which produces a fibrous protein known as keratin. Keratin provides a tough protective layer for the epidermis. 2. Fat cells in the subcutaneous tissue, deep to the dermis, cushions blows. 3. Pressure receptors alert the nervous system to possible damage.

The layer responsible for whorled ridges on the epidermal surfaces is indicated by ________.

Label A

The arrector pili muscle is represented by ________.

Label B

The gland that produces a mixture of oily substances and fragmented cells is indicated by ________.

Label C

The hypodermis, or subcutaneous tissue, is represented by ________.

Label D

The gland that produces sweat is indicated by ________.

Label E

The hair follicle is indicated by ________.

Label F

Differentiate among the roles of melanocytes and keratinocytes. Where in the skin are these cells located?

Melanocytes are located in the stratum basale of the epidermis. These cells produce a pigment, melanin, upon exposure to the skin. Melanin functions to protect the dermis from damage due to UV radiation. Keratinocytes form most of the cells of the epidermis; they produce a water-resistant, tough protein called keratin.

Stratum corneum

Superficial layer of the epidermis made of 20-30 cell layers of dead, keratin-filled cells

Apocrine gland secretions are normally odorless, and may be milky or yellowish in color.

TRUE

Cutaneous membranes are the only dry membranes.

TRUE

Hair is produced by the hair bulb and is composed primarily of dead keratinized cells.

TRUE

Nails and hair are composed of keratin.

TRUE

Squamous cell carcinoma arises from cells of the stratum spinosum.

TRUE

The dermis is composed mostly of dense connective tissue.

TRUE

The epidermis is made up of stratified squamous epithelium.

TRUE

The majority of the cells in the epidermis are keratinocytes.

TRUE

The pattern that produces fingerprints is produced by dermal papillae in the dermis.

TRUE

The pinkish hue of healthy individuals with fair skin is the result of the crimson color of oxygenated hemoglobin circulating in the dermal capillaries and reflecting through the dermis.

TRUE

The rule of nines is used to estimate how much of the body surface is burned.

TRUE

Explain the ABCD rule.

The ABCD rule describes the appearance of the most serious form of skin cancer, melanoma. The "A" is for asymmetry. In melanoma, the two sides of the pigmented spot or mole do not match. The "B" is for border irregularity. In melanoma, the borders of the lesion are not smooth but exhibit indentations. The "C" is for color. In melanoma, the pigmented spot contains areas of different colors (blacks, browns, tans, and sometimes blues and reds). The "D" is for diameter. In melanoma, the spot is larger than 6 mm in diameter (the size of a pencil eraser).

Explain how the skin helps regulate body temperature.

The nervous system is responsible for controlling all temperature-regulating functions of the skin. When the temperature in the external environment is high, heat loss occurs as the nervous system activates sweat glands. Perspiration is produced, which evaporates from the skin surface, causing heat to be dissipated. At the same time, the nervous system causes blood to be flushed into skin capillary beds so that heat radiates from the body surface. In contrast, when the temperature in the external environment is low, the nervous system prevents blood from entering the skin capillary system and radiation to the body exterior is prevented so that perspiration does not occur.

mucous membrane

Type of membrane adapted for absorption or secretion Type of membrane that lines open body cavities

cutaneous membrane

Type of membrane that forms the skin

synovial membrane

Type of membrane that lines the fibrous capsules surrounding joints

serous membrane

Type of membrane that secretes fluids around organs Type of membrane that contains a visceral and a parietal layer Peritoneum, pericardium, and pleura are examples of this type of membrane

Papillary layer of dermis

Upper layer of the dermis that forms dermal papillae

"Goosebumps" are caused by contractions of the ________.

arrector pili muscles

Hairs are found associated with the ________.

axillary region

Sebum is responsible for all of the following EXCEPT ________.

body temperature regulation

The secretion of sweat is stimulated ________.

both by high temperatures and by hormones, especially male hormones

People who produce a lot of melanin have a skin tone that is ________.

brown

First-degree burn

burn in which only the epidermis becomes red and swollen

Malignant melanoma

cancer of melanocytes

Squamous cell carcinoma

cancer of stratum spinosum cells

Which of the following homeostatic imbalances is caused by a herpes simplex infection?

cold sores