Chapter 10 Physiology and Histology of the Skin

Stratum Corneum

horny layer, top layer of skin, 15-20 layers of cells. keratinocytes are squamous and cornified

What is not an element of the skin's acid mantle

blood

What are eccrine glands

sweat glands

What cells identify molecules that have foreign peptides, and help to regulate immune response

t cells

What is glycation

the binding of a protein molecule to a glucose molecule

Keratinocytes

composed of keratin, 95 percent of epidermis

Tyrosinase

enzyme that stimulates melanocytes and thus produces melanin

What are keratinocytes

epidermal cells composed of keratin, lipids, and other proteins

What hormone stimulates cells to reproduce and heal

epidermal growth facor

What does the skins barrier function protect us from, in addition to irritation

intercellular water loss

What glands help regulate the body's temperature?

sudoriferous glands

What are follicles

tubelike openings in the epidermis

What is the dermis

support layer below the epidermis

Stratum Germinativum

Basal Cell layer, 5th layer of epidermis, stem cells (mother cells) undergo mitosis. Melanocytes are here

How does skin get its nourishment?

Blood and Lymph

What are the items in the dermis that respond to touch, pain, cold, heat, and pressure?

sensory nerve endings

What are most abundant in the fingertips, as opposed to other parts of the body

sensory nerve fibers

define afferent nerves

sensory nerve, nerve fibers send messages to central nervous system and brain to react to heat, cold, pain, pressure, and touch

Where in the body is hyaluronic acid found

skin

What does barrier function mean?

skins way of protecting from irritation caused by TEWL

Stratum Spinosum

spiny layer, 4th layer of epidermis lipids, proteins, and desmosomes formed here Langerhans immune cells are here

What function does the enzyme tyrosinase perform

stimulates melanocytes and thus produces melanin

What part of the skin provides a protective cushion and energy storage for the body

subcutaneous layer

What are the glands that excrete perspiration, regulate body temperature, and detoxify the body

sudoriferous

What causes skin cells built in antioxidants to lose their ability to protect cells

sun exposure

Onyx

technical term for nail

Dermis

thickest layer of skin, called derma, corium, cutis, or true skin; support layer of connective tissues below the epidermis

Stratum Granulosum

third layer of epidermis; granular layer; production of keratin and intercellular lipids takes place here enzymes desolve desmosomes form skins waterproofing barrier function

Why does the body perspire

to protect us from overheating

What forms skins waterproofing barrier function?

triglycerides, ceramides, waxes, fatty acids, and intercellular lipids excreted from cells in stratum granulosum

Where in the body are the coiled structures known as apocrine glands found

underarm and genital area

What is the acid mantle

Protective layer of lipids and secretions on the skin's surface

What are the two main glands associated with the skin?

Sebaceous Glands; Produce oil - connected to hair follicles Sudoriferous Glands; excrete sweat...

What are the six main functions of the skin?

1. Protection-outside elements - bacteria 2. Sensation 3. Heat Regulation- sweat glands and blood flow 4. Excretion- sweat glands detoxify 5. Secretion- sebum protects the skin surface 6. Absorption- of ingredients, water, & O2 for skin's health

Name the five layers of the epidermis

1. Stratum Corneum 2. Stratum Lucidum 3. Stratum Granulosum 4. Stratum Spinosum 5. Statum Germinativum

How many times thicker than the epidermis is the dermis, approximatley

25

What is the average internal temperature of the body in degrees fahrenhiet

98.6

What are the two types of sweat glands (sudoriferous)?

Apocrine - attached to hair folicle found in arm pit and genital area Eccrine- found all over body

What causes the body to produce its own vitamin D

Exposure to the sun

What is rue of the reticular layer of the skin

It is the deepest layer of the dermis

What is true of the epidermis

It is the outermost layer of the skin

What are keratinocytes?

Keratin cells that contain protein and lipids. Protect from water loss and dehydration

What are guard cells of the immune system that sense unrecognized foreign invaders, such as bacteria

Langerhans immune cells

Name the two main types of nerves and describe what they do?

Motor; convey impulses from the brain to muscles or glands Sensory; send message to central nervous system to react to heat, cold, pain, pressure, and touch

Name the two layers of the dermis

Papillary and reticular layers

What are the names of two layers in Dermis

Papillary layer Reticular Layer

Two types of melanin

Pheomelanin- red to yellow in color Eumelanin - dark brown to black

Why is the skin elasticity important

The skin has to be elastic so that it can expand and contract, be strong so that it can protect the body and it must be able to repair itself.

Describe the difference between UVA wavelengths and UVB wavelengths

UVA are ageing and long UVB are Burning and short in length...

How does UVA and UVB radiation affect the skin?

UVA cause genetic damage and cell death UVB causes burning of the skin & contributes to synthesis of Vit D

Why is UVB radiation also known as burning rays?

UVB wavelengths cause burning of the skin as well as cancer

Where in the skin is the stratum germinativum located

above the papillary layer of the dermis

What is another name for subcutis tissue

adipose tissue

What is a common term for UVA radiation

aging rays

What function do desmosomes perform

assist in holding cells together

What is the common name of the stratum germiniativum

basal layer

subcutaneous tissue

below reticular layer, loose connective tissue or adipose tissue. protective cushion that gives contour and smoothness to the body, as well as providing a source of energy for body.

What are corneocytes

hardened kertatinocytes

What causes telangiectaisa

capillary damage

What are melanocytes?

cells that produce pigment granules in the basal layer

What are melanocytes

cells that produce skin pigment granules in the basal layer

Where in the face does the chronic condition rosacea primarily appear

cheeks and nose

What are free radicals?

chemically active atoms or molecules with unpaired electrons. Unequal number of electrons and unbalanced charge.

Melanin

complex protein which determines skin, eye, and hair color

What are hair papillae

cone shaped elevations at the base of the follicle

define nerves

cordlike bundles of fibers made of neurons where sensory stimuli and motor impulses pass

telangiectasia

couperose skin, the dilation of capillary walls

What is the common name for the stratum corneum

horny layer

What causes injured skin to restore itself to its normal thickness

hyperproduction of cells

What is another name for the subcutaneous layer of the skin

hypodermis

What are membranes of ridges and grooves that attach to the epidermis

dermal papillae

Where in the skin are lymph vessels located

dermis

What protein fiber is found in the dermis and gives skin its flexibility and firmness

elastin

What causes transepidermal water loss

evaporation

Keratin

fiberous protein provides resiliency and protection to the skin, found in all layers of the skin

What performs the function of stimulating cells, collagen, and amino acids that form proteins

fibroblasts

elastin

fibrous protein that forms elastic tissue and gives skin its elasticity

What is collagen

fibrous tissue made from protein

define extracellular matrix in dermis

fluid matrix in dermis composed of collagen, proteins, and glycosaminoglycans. Maintains water balance, dermal support, and assist cell metablolism, growth and migration.

Merkel Cells, in basal layer

found in stratum germinativum layer; touch receptors (finger tips)

What are ceramides

glycolipid materials

What is the result of the contraction of the arrector pili muscle

goose bumps

What is the commonname of the stratum granulosum

granular layer

What is true of the stratum corneum

it is the outermost layer of the skin

What is true of the papillary layer of the skin

it is the top layer of the dermis

What forms the cells in the stratum granulosum that resemble granules

keratin

What is a fiber protein found in skin, hair, and nails

keratin

Desmosomes

keratin filaments, protein bods that create the junctions between the cells. Strengthen and aid in intercellular communication.

Desquamation

keratinocytes are shed from skin, happens on stratum corneum

squamous cells

keratinocytes on surface of stratum corneum, flat and scaly keratinized cells

define papillary layer of dermis

layer of dermis that connects the dermis to the epidermis, forming the epidermal/dermal junction

define Reticular layer

layer of dermis that is denser and deeper of the dermis, comprised of collagen and elastin

What protein determines hair, eye, and skin color

melanin

cell turnover

process of desquamation and replacement, happens on stratum corneum

define efferent nerves

motor nerve, fibers that convey impulses from brain or spinal cord to muscles or glands

What is true of sun exposure

of all factors, it has the greatest impact on how our skin ages

define sabaceous glands

oil glands, connected to hair follicles and produce oil, protects surface of skin

What is hydrolipidic film

oil water balance that protects the skins surface

What is the other type of melanin the body produces, besides eumelanin

pheomelanin

Melanosomes

pigmanet carrying granules that produce melanin

What are melanosomes

pigment carrying granules that produce melanin

What term do clients commonly use when referring to follicles

pores

Langerhans immune cells, in spiny layer

protect the body from infections by identifying foreign material

What is the acid mantle?

protective barrier of lipids and secretions on the surface of the skin

How does sebum protect the skin?

protective oil that keeps skin soft & protects from outside elements. Slows down TEWL

What is collagen?

protein substance of complex fibers that gives skin its strength & is necessary for wound healing

Collagen

protein substance of complex fibers that gives skin its strength and is necessary for wound dealing produced by fibroblasts

What is not one of the six primary functions of the skin

reflection

What protects the surface of the skin

sebaceous glands

What is not a compound in the body from which free radicals take electrons

sebum

What oil that provides protection for the epidermis from external factors and that lubricates both the skin and hair

sebum

Stratum Lucidum

second layer of epidermis, thin, clear layer of dead skin cells. Translucent layer Keratinocytes contain clear keratin thickest on palms and soles of feet; fingerprints and footprints

What comprises about 50 to 70 percent of the skin

water

Corneocytes

waterproof protective cells, hardened, in stratum corneum

When do free radicals produce more free radicals

while causing oxidation reactions