A&P Chapter 5

What is included in the cutaneous membrane?

Epidermis and Dermis

glycolysis occurs in the

cytoplasm

Thick skin is found...

on the palms of the hands and the soles of the feet

Hair production occurs in the __________.

reticular layers of the dermis

What is the most superficial layer of the epidermis?

stratum corneum

A thick, flattened mass of scar tissue that grows into the tissue around an injury site is called __________.

a keloid

When scar tissue formation continues beyond the requirements of tissue repair, __________ is formed.

a keloid

Functions of hair follicles

protect skull and provide delicate touch sensations on general body surface

Differences in skin color among individuals are the result of __________.

- differences in the number of melanocytes - the different levels of melanin synthesis

Approximately how long does it take for a cell to move from the stratum germinativum to the stratum corneum?

15 to 30 days

Excessive exposure of the skin to ultraviolet radiation may cause redness, edema, blisters, and pain. The presence of blisters classifies the burn as __________.

2nd degree burn

Why are lines of cleavage clinically significant?

A cut parallel to the cleavage line will remain closed

What is the significance of the lines of cleavage?

Cuts made parallel to the lines of cleavage heal with little scarring.

__________ in the stratum germinativum form patterns of depressions and elevations that are especially noticeable on the fingertips.

Epidermal ridges

T or F: The blood clot that forms at the site of an epidermal injury is called granulation tissue.

False. Granulation tissue is composed of a blood clot, fibroblast, and a newly formed network of capillaries

T or F: The secretions of apocrine sweat glands have antibacterial action.

False. Secretions of sudoriferous glands provide nutrients for bacteria.

T or F: Vellus hairs are found on your head, eyebrows, and eyelashes.

False. Vellus hairs are the "peach fuzz" hairs located over much of the body's surface.

Accessory structures in the integumentary system

Hair follicles, exocrine glands, and nails

Functions of the reticular layer

Has sensory receptors that detect touch, pressure, pain, vibration, and temperature. Blood vessels assist in thermoregulation

How do third-degree burns differ from first- and second-degree burns?

In a third-degree burn, the epidermis, dermis, and hypodermis are destroyed

Why is limited exposure to UV light in sunlight beneficial?

It converts a steroid into vitamin D3.

Which of the following is an effect of epidermal growth factor?

It promotes divisions of the germinative cells in the stratum germinativum.

A decrease in the number of __________ leads to increased damage and infection associated with age.

Langerhans cells

What are Langerhans cells?

Langerhans cells are dendritic cells (antigen-presenting immune cells) of the skin and mucosa, and contain large organelles called Birbeck granules. They are present in all layers of the epidermis but are most prominent in the stratum spinosum.

The peptide that is secreted by the pituitary gland and increases the rate of melanin production is __________.

MSH (melanocyte-stimulating hormone)

Which of the following is NOT an effect of aging on the integumentary system?

Melanocyte activity increases, darkening the skin.

Functions of the papillary layer

Nourishes and supports epidermis

Functions of nails

Protect and support tips of fingers and toes

8 functions of the integumentary system

Protection- protects tissues and organs against impact, abrasion, fluid loss, and chemical attack Excretion- excretes water, salts, and organic wastes by integumentary glands Maintenance- maintains normal body temp through either insulation or evaporative cooling Production- produces melanin that protects tissue from UV radiation, and keratin which protects against abrasion and serves as water repellent Synthesis of vitamin D3- a steroid that is converted to calcitriol, a hormone important to normal calcium metabolism Storage- stores lipids in adipocytes in the dermis and in adipose tissue in the hypodermis (subcutaneous layer) Detection- detects touch, pressure, pain, vibration and temperature stimuli and relay info to the nervous system Coordination- coordinates the immune response to pathogens and cancers in the skin

Functions of the epidermis

Protects the dermis, prevents water loss and the entry of pathogens and synthesizes vitamin D3. Sensory receptors detect touch, pressure, pain and temperature

Why are malignant melanomas extremely dangerous and life-threatening?

The melanocytes grow rapidly and metastasize through the lymphatic system

T or F: Apocrine sweat glands are associated with hair follicles.

True. Apocrine sweat glands are associated with hair follicles.

T or F: Another name for the eponychium is cuticle.

True. The eponychium is a portion of the stratum corneum of the nail root that extends over the exposed nail.

When the body temperature becomes abnormally high, thermoregulatory homeostasis is maintained by __________.

an increase in sweat gland activity and blood flow to the skin

What are the primary tissues composing the hypodermis?

areolar and adipose tissue

Where can you find an apocrine sweat gland?

armpits, nipples, and pubic regions

Special smooth muscles in the dermis that, when contracted, produce "goose bumps" are called __________.

arrector pili

What is the name of the muscle that is connected to the hair follicle and produces "goose bumps" when it contracts?

arrector pili

Functions of exocrine glands

assist in temperature regulation and waste excretion

What is the first step of integument repair following an injury?

bleeding and inflammation

When ruptured dermal blood vessels leak into the dermis, a __________ may form.

bruise

Which of the following would result in the loss of large portions of the skin and lead to increased risk of infection and fluid loss?

burns

Which of the following is an orange-yellow pigment that is found in certain food items, such as carrots and squash?

carotene

The dermis includes

papillary layer and reticular layer

Which type of gland produces earwax?

ceruminous gland

Yellowing of the fingernails occurs in patients who have __________.

chronic respiratory disorders, AIDS, or thyroid gland disorders

What are the two basic factors interacting to produce skin color?

circulatory supply and pigment concentration and composition

A hair at the end of the growth cycle is called __________.

club hair

The body of the nail __________.

consists of dead, tightly compacted cells

Skin exposure to small amounts of ultraviolet radiation serves to __________.

convert a steroid related to cholesterol into vitamin D

Sagging and wrinkling of the integument is due to __________.

decrease in the fibrous elastic network of the dermis

Hair turns gray or white because of __________.

decreased melanocyte production

What condition causes inflammation in the papillary layer when a part of the skin is exposed to infection or an irritant?

dermatitis

What are the two layers of the cutaneous membrane (skin)?

dermis and epidermis

The integumentary system contains two components, the outer __________ and the underlying dermis, along with several accessory structures.

epidermis

Ceruminous glands are modified sweat glands located in the __________.

external auditory canal

Accessory structures include

hair follicles and the sebaceous and sweat glands

What is the subcutaneous layer that separates the integument from the deep fascia around other organs?

hypodermis

Which of the following layers is composed of adipose and areolar tissues and is the site of subcutaneous injections?

hypodermis

Which type of cell is the most abundant epithelial cell in the body and dominates the cellular composition of the epidermis?

keratin cells

The hypodermis is useful for subcutaneous injection by hypodermic needle because it has __________.

limited number of capillaries and no vital organs

Starting from the basal layer, cells gradually ___ organelles until they fill with protein.

lose

What is the name of the pale, crescent-shaped area near the root of the nail?

lunula

The core of a hair is called the __________.

medulla

Which of the following is a brown, yellow-brown, or black pigment produced by pigment cells in the stratum germinativum?

melanin

Which gland functions in thermoregulation?

merocrine sweat gland

Thin skin covers...

most of the body's surface

Nail production occurs at an epithelial fold NOT visible from the surface called the __________.

nail root

Nail production begins at the __________.

nail root This is the base of the nail.

The dermis is divided into an upper __________ layer and the deeper reticular layer.

papillary

Which layer of the dermis contains areolar tissue and is found immediately under the epidermis?

papillary layer

The practical limit to the healing process of the skin is the formation of inflexible, fibrous, noncellular __________.

scar tissue

Which gland produces an oily secretion that lubricates the hair and skin?

sebaceous gland

Sebaceous glands release which type of secretion?

sebum

The secretion that lubricates and inhibits growth of bacteria on the skin is called __________.

sebum

An important function of the hypodermis is to __________.

stabilize the position of the skin in relation to underlying tissues

Epidermal cells in the stratum spinosum and stratum germinativum function as a chemical factory in that they can convert __________.

steroid precurors to vitamin D when exposed to sunlight

The strata in order from basement membrane to the free surface

stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, stratum corneum

The layers of the epidermis, beginning with the deepest layer and proceeding outward, include the strata __________.

stratum basale/germinativum stratum spinosum stratum granulosum stratum lucidum (in thick skin only) stratum corneum

In which layers of the epidermis do mitotic divisions occur?

stratum basale/germinativum and stratum spinosum

Which epidermal stratum is the most superficial and is composed of 15-30 layers of dead, keratinized cells that eventually are shed from its surface? Also known as the horny layer.

stratum corneum

Psoriasis is a skin disorder in which there is abnormal increased mitotic activity in the __________.

stratum germinativum

Which epidermal layer is found only in thick skin?

stratum lucidum

Hypodermis

superficial fascia or subcutaneous layer. Separates integument from the deep fascia around other organs, such as muscles and bones

Which of the following functions is NOT associated with the skin? - excretions of salts, organic wastes, and water - detection of sensory information -synthesis of B vitamins maintenance of normal body temperatures

synthesis of B vitamins

What is the term for heavy, more deeply pigmented hairs found in the scalp, eyebrows, and eyelashes?

terminal hairs

Keratinocyes

the body's most abundant cell. Form several layers or "strata" and contain large amounts of the protein keratin.

The terms thick and thin refer to...

the relative thickness of the epidermis, not to the cutaneous membrane as a whole

What is the natural factor responsible for varying shades of hair color?

type of melanin present

Which of the following are benign tumors that occur in the skin? - warts - contusions - hives - keloids

warts

Because fresh water is hypotonic to body fluids, sitting in a freshwater bath causes __________.

water to enter the epidermis, causing the epithelial cells to swell