A&P Chapter 5.1 Functional Anatomy of the Skin

stratum spinosum

Which layer of the epidermis contains dendritic (langerhans) cells?

stratum lucidum

Which layer of the epidermis means "clear layer"?

stratum granulosum

Which layer of the epidermis means "grainy layer"?

stratum spinosum

Which layer of the epidermis means "spiny layer"?

albinism

a disorder caused by the absence of melanin production (melanocytes lack the enzyme needed to produce melanin)

erythema

redness resulting from inflammation of sun-damaged tissue

epidermis

"thick" and "thin" refer to the relative thickness of just the ____________________, not the cutaneous membrane as a whole

status corneum

*outer layer of epidermis* that is at the exposed surface of both thick and thin skin; contains 15 to 30 layers of *keratinzed cells* and is *water resistant*

melanosomes

Pigment carrying granules that produce melanin, a complex protein.

paralell

A cut _______________ to a tension line will usually remain closed and heal with little scarring

rule of nines

A system that assigns percentages to sections of the body, allowing calculation of the amount of skin surface involved in the burn area.

fluid and electrolyte balance

Even areas with partial-thickness burns *lose effectiveness as barriers to* fluid and electrolyte loss

tension (cleavage) lines

Gaps found between collagen bundles in dermis create indentations in epidermis

Stratum corneum

In thick skin, what is the thickest (most cell layers) stratum of the epidermis?

Stratum basale and stratum spinosum

In which layers of the epidermis do mitotic divisions occur?

less

Light-skinned people produce (more/less) melanin than dark-skinned people

blood vessels, capillaries

Like all other epithelia, the epidermis lacks local _________________________ so they rely on __________________________

3rd

Loss of sensation and the absence of a reaction to a pin prick indicates the presence of a (1st/2nd/3rd) degree burn

melanin

Skin color differences are due to the amount of _______________ produced, not the number of melanocytes

keratinoyctes

The body's most abundant epithelial cells that dominate the epidermis, forming *strata* and are *continuously produced* in the deepest layers and *shed at the surface*

desmosomes

The dead cells in each layer of the stratum corneum are tightly interconnected by __________________

stratum basale

The deepest layer of the epidermis which is *attached to the basement membrane by hemidesmosomes* separating the epidermis from the dermis; dominated by *basal cells*

strata

The epidermis is composed of ______________ that have various functions

stratum granulosum

The layer of the epidermis that has *3-5 layers of keratinocytes* where *cells make keratin and keratohyalin*

Dense irregular connective tissue

The reticular layer of the dermis is composed of what kind of tissue?

cutaneous membrane

The skin made up of the *epidermis and the dermis*

dermis

This lies between the epidermis and the subcutaneous layer with *two types of fibers* (collagen, and elastic) that tolerate stretching

sensible perspiration

Water loss due to secretion by sweat glands that *you can feel*

subcutaneous fat

What accumulates at the beginning of puberty

1. fluid and electrolyte balance 2. thermoregulation 3. protection from infection

What are the 3 skin functions affected by burns?

carotene and melanin

What are the primary pigments involved in skin coloration?

Areolar and adipose

What are the primary tissues comprising the hypodermis?

epidermis, dermis, hypodermis

What are the three layers of the skin from external to internal?

free nerve endings, tactile discs

What are the touch receptors found in the epidermis?

tactile corpuscles, lamellar corpuscles, bulbous corpuscles

What are the touch receptors found tin the dermis?

circulation and pigment concentration

What are the two basic factors that interact to produce skin color?

dermis and epidermis

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

papillary, reticular

What are the two layers of the dermis?

cutaneous membrane, accessory structures

What are the two main parts of the integumentary system?

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

What is the correct order of strata from the basement membrane to the free surface of the epidermis?

hypodermis

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

keratin

What is the water-resistant, fibrous protein that fills the cells of the outer layers of the epidermis and helps slow dehydration?

third-degree burn

What type of burn is this?: the skin cannot repair itself because granulation tissue cannot form and epithelial cells are unable to cover the injury; *needs skin grafting*

second-degree burn

What type of burn is this?: the skin is blistered, painful, and swelling and takes 1-2 weeks to heal

first-degree burn

What type of burn is this?: the skin is red and painful

pale

When blood supply is temporarily reduced, the skin may become _____________.

flushed

When your vessels are dilated, the bright red oxygen-bound hemoglobin in the blood causes the skin to become _______________________.

Stratum lucidum

Which epidermal layer is found only in thick skin?

stratum corneum

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?

lipids

Which of the following does the integument not synthesize or produce?

melanin

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

hypodermis

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

keratinocytes

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

A cut parallel to a cleavage line will remain closed.

Why are lines of cleavage clinically significant?

skin

_________ cancers are the most common types of cancer

metastasis

____________________ virtually never occurs in basal cell carcinomas, so most people survive

tactile disc

a Merkel cell along with a sensory nerve terminal

cyanosis

a bluish discoloration of the skin resulting from declining oxygen levels that causes hemoglobin to turn a darker red

melanin

a brown, yellow-brown, or black pigment produced by melanocytes

first-degree burn

a burn in which only the *surface of the epidermis is affect* (ex. a sunburn)

second-degree burn

a burn in which the *entire epidermis* and *maybe some of the dermis* are damaged

third-degree burn (full-thickness)

a burn that *destroys the epidermis and dermis* and *extends to the subcutaneous layer*; less painful than second-degree because *sensory nerves are destroyed

malignant melanoma

a condition in which cancerous melanocytes grow rapidly and metastasize through the lymphatic system

at a right angle

a cut _______________________ to a a tension line will be pulled open as severed elastic fibers recoil, resulting in scarring

subcutaneous layer

a layer *NOT apart of the skin* that separates the skin from deeper structures and permitting independent movement; dominated by *adipocytes* which have *fats that store energy*

stratum spinosum

a layer of the epidermis consisting of *8-10 layers of keratinocytes* bound by *desmosomes* and containing *dendritic cells*

stratum lucidum

a layer of the epidermis found only in the thick skin of the fingers, palms, and soles filled with *keratin and keratohyalin* and separates the stratum corneum from the deeper layers

autograft

a patients *own undamaged skin* used in a skin graft

split-thickness graft

a skin graft involving the transfer of the *epidermis and superficial portions of the dermis*

skin graft

a surgical procedure in which areas of intact skin are transplanted to cover the site of a burn

central adiposity

an excessive amount of abdominal fat that is strongly correlated with cardiovascular disease

carotene

an orange-yellow pigment that normally accumulates in epidermal cells; most apparent in the stratum corneum of light-skinned poeple and in vegetables

xenograft

animal skin used in a skin graft

20

burns that cover more than _______% of the skin threaten critical homeostatic functions of the skin

merkel cells

cells involved with touch sensations that are scattered among the basal cells

melanocytes

cells located in the stratum basale that manufacture melanin from the amino acid tyrosine and package it in vesicles called melanosomes

Dendritic (Langerhans) cells

cells which participate in the immune response by stimulating a dense against microorganisms that manage to penetrate the superficial layers of the epidermis and superficial skin cancers

accessory structures

components with supporting functions in the skin

dermis

the *middle layer of skin* that consist of a papillary layer and reticular layer

dermal papillae

dermal projections that project into the epidermis; *increase surface area for attachment* and *bind epidermis to the dermis*

allograft

frozen skin from a cadaver used in a skin graft

thermoregulation

increased fluid loss causes *increased cooling by evaporation* so more energy is expended to maintain body temperature

insensible perspiration

interstitial fluid lost by evaporation through the stratum corneum that you are *unable to feel*

stratum lucidum, stratum granulosum

keratohyalin is found in the ____________________________ and ________________________.

integument

skin

basal cells

stem cells whose divisions replace the more superficial keratinocytes that are lost or shed at the epithelial surface

subcutaneous layer

the *innermost layer of the skin* that separates the integument from the fascia around deeper organs *(NOT part of the integument)*

basal cell carcinoma

the *most common* form of skin cancer; originates in the stratum basale resulting from *mutations from overexposure to UV radiation*

epidermis

the *outermost layer of skin* consisting of a stratified squamous epithelium

subcutaneous

the _____________________ layer connects the dermis to underlying tissues

reticular layer

the bottom layer of the dermis consisting of an interwoven meshwork of *dense irregular connective tissue* containing both *collagen* and *elastic* fibers; contain blood and lymphatic vessels and nerve fibers

epidermal ridges

the deeper layers of the epidermis which extend into the dermis; *increase surface area for attachment* and *bind epidermis to the dermis*

keratinization

the formation of a protective, superficial layer of cells filled with keratin

reticular layer

the innermost layer of the dermis consisting of dense irregular connective tissue

papillary layer

the layer of the dermis that consists of *highly vascularized areolar tissue*, containing capillaries, lymphatic vessels and sensory nerve fibers

integumentary system

the most accessible and often the least appreciated organ system, making up 16% of your total body weight; your body's *first line of defense* against the environment

cutaneous plexus

the network of arteries and veins connected to smaller vessels servicing the tissues of the integumentary system

papillary layer

the outermost layer of the dermis consisting of areolar tissue

lamellar (pacinian) corpuscles

these are sensitive to *deep pressure and vibration*; found in *dermal layers* and *subcutaneous layer*

Bulbous (Ruffini) corpuscles

these are sensitive to *pressure and stretching of skin*; round in *reticular layer of the dermis*

free nerve endings

these are sensitive to touch and pressure, *found between epidermal cells*

tactile (meissner) corpuscles

these detect sensations of *delicate touch, pressure and vibration*; found in the *papillary layer of the dermis*

tactile discs

these detect sensations of *texture* and *steady pressure*; found in the *deepest layer of the epidermis*

subpapillary plexus

this lies *deep to the papillary layer* of the dermis and is a network of *blood vessels that supplies blood to capillaries* that provide oxygen and nutrients to the dermis and epidermis

thin skin

this skin covers most of the body surface, containing *4 strata*

thick skin

this skin is found on the *palms of your hands* and the *soles of feet* and has a *fifth stratum*

stratum basale

which layer of the epidermis contains basal and Merkel cells?

because the patient's immune system will reject them within 7-21 days

why are allografts and xenografts only temporary?

there are no vital organs and capillaries are sparse

why is the subcutaneous layer a common site for injections with hypodermic needles?

sepsis

widespread bacterial infection that is the leading cause of death in burn victims