Unit 6

what is the largest organ in the body?

skin

integumentary system contains which organs

skin, nails, hair, sebaceous gland, sweat glands

what are the two tissue layers of the skin

epithelial tissue overlying connective tissue

what is the outer layer of the skin

epidermis

what is the inner layer of the skin

dermis

a function of the skin

help produce vitamin D

what are the tissues that make up epidermis

stratified squamous epithelium

what makes up an organ

two or more tissues grouped together and perform a specialized function

which layer of skin is thicker

dermis

what are the tissues that make up dermis

connective tissue, and contains collaginous and elastic fibers

another word for subcutaneous layer

hypodermis

hypo prefix meaning

under

epi prefix meaning

above

where is hypodermis located

under the dermis

what tissues make up the subcutaneous layer

areolar and adipose connective tissue

subcutaneous layer contains what that helps supply skin

blood vessels

subcutaneous layer defintion

beneath dermis, insulating layer

epidermis features

lacks blood vessels, made up of stratified epithelium. rests on basement membrane

where does epidermis get its nutrients from and why

dermis, because epidermis lack blood cell

name of deepest layer of epidermis

stratum basale, and it is nourished by blood vessel from dermis

as cells grow in the epidermis where do they go

migrate torward free surface away from nutrient supply

what is at the most superficial layer of epidermis

dead cells filled with keratin in a flattened squamous shape

what is keratinization and where does it occur

process of hardening, dehydration, and keratin accumulation that occurs in epidermal cells as they migrate outward

keratin

tough fibrous waterproof protein made and stored in cells

what produces keratin

specialized cells called keratinocytes

name of outer epidermis layer formed when cells reaching outer surface of skin

stratum corneium, tightly packed there I THINK

5 layer of epidermis (superficial to deep)

stratum corneum, lucidum, granulosum, spinosum, basale/germinativum

epidermis function

protect against water loss, harmful chemicals, mechanical injury, pathogens

stratum corneum

layer of keratin from dead epithelial cells that no longer have nucleus and flattened, typically get shed off from skin

stratum lucidum

clear layer, nuclei, organelles and cell membranes no longer visible. found in thick skin only (areas like palms of hand or sole of feet)

what type of skin is stratum lucidum found in

thick skin, like palm of hand or sole of feet

stratum granulosum

3-5 layers of flattened dying cells, contain granules. full of shrunken keratin and shriveled nuclei

stratum spinosum

layer of live cells that synthesize keratin. cells becoming flattened. layers of cell with centrally located, large, oval nuclei

what is the deppest layer of epidermis

stratum basale/germinativum

straum basale

basil layer of epidermis, single layer of cells and connected to dermis by basement membrane, in stratum basale there is cell division that replaces layer of epithelial cells that are lost from the surface.

what increases rate of division in stratum basale

damage or stress to skin

how does stratum cornieum get thicker and what does this form

it gets thicker by repeated stress to specific area. forms calluses

how does stratum basale get nutrients

blood vessels from dermis

what layer of epidermis is actively dividing and going through mitosis

stratum basale

stratum basale structure

single row of cuboidal/columnar cells

where are melanocytes found which specific skin layer

stratum basale

how often do cells in epidermis divide

seven times more frequently than normal

what produces melanin

melanocytes

melanin function

absorb UV light from sunlight, gives u ur skin color

where is melanin distributed

into your caratinosytes to protect skin cells from damaging effects of UV light

keratinocytes and its function

most of epidermal cells, synthesize lots of keratin

dendritic cells.which specfic skin layer is it in and what is its function

macrophages in stratum spinosum. engulfs different pathogens and things in skin, and help prevent infection

tactile cells and their specific skin layer location. what are they associated with?

sensory cells in stratum basale, associated with neurons or nerve cells in dermis

where are tactile cells located specific skin layer

stratum basale

factors that effect skin color

hereditary factors, environment factors like sunlight, uv light, xray

what varies amongst people: number of melanocytes or melanin

melanin produced. everyone has same melanocyte number

physiological factors that affect skin color

oxygenation in blood of dermal blood vessels, accumulation of keratin pigment from diet, jaundice

cyanosis

nail beds turn blue due to lack of oxygen in tissues

erythema

skin will redden. can be caused by embarassment/blushing

pallor

paleness, can indicate stress, anemia or low blood pressure. result of reduced amount of hemoglobin with oxygen

jaundice

yellow of skin indicated liver disorder. accumilation of billyrubin

bruises indicate what

hematamas. indicates clot underneath skin

what is the average thickness of dermis

1-2mm thick

where is dermal papilla found

dermis, between epidermal ridges

dermal papilla function

anchor the epidermis to the dermis, increasing surface area for nutrient/waste exchange, and housing sensory receptors for touch/temperature. In hair follicles, they act as signaling centers, directing hair growth, shape, and color by interacting with epithelial cells

dermis

contains nerve cell processes, you also have dermal blood vessels that supply nutrient to all of skin cells

where are hair follicles, sebaceous gland found

dermis

what causes fingerprints

dermal papilla. Epidermis has epidermal ridges that fit into dermalpapilla at top of dermis and those grooves make up fingerprints

what are the touch receptors of the skin

pacinian corpuscle, meissner’s corpuscle, merkel disk

pacinian corpuscle purpose

help detect deep pressure,

where are pacinian corpuscle found

in joints

meissners corpuscle helps detect what

help detect light touch, found in upper dermis

merkel disks and which layer of skin it is located in

located in epidermis, helps identify shapes, edges, rough textures. found in hands

what are the layers of the dermis

papillary layer and reticular layer

papillary layer location and what tissues is it made up of

superficial layer of dermis, makes up about 20%. made up of areolar connective tissue. dermal papilla located here

reticular layer and tissue type and function

deeper layer of dermis. made up of dense irregular connective tissue. provide strength

what is thicker papillary or reticular layer

reticular layer

acessory structures of skin and where do they originate

hair follices, nails, skin glands. originate from epidermis and extend into dermis/hypodermis

3 parts of a nail

nail plate, nail bed, lunula

nail bed

surface of skin thats underneath nail plate

lunula

white part of nail. most active growing region of nail

where is hair present

all surface except palms, soles, lips, etc

hair follicle

tube-like depression of epidermal cells from which hair develops. extends into dermis or subcutaneous layer

parts of hair

hair bulb, hair root, hair shaft

hair shaft live or dead cells?

section above surface of skin. packed with keratin from deadcells

hair root location and what it is made of

section in skin, made up of deadcells ifull of keratin

hair bulb. live or dead cell?

deepest part of hair. live cells found

hair papilla contains what that nourishes hair

contains blood vessels that help nourish hair

where do u get hair color from

amount of melanin u produce

erector pilli muscle

involved in giving goosebumps, makes hair stand up straight, can also help in body temp

sebaceous glands is associated with what? what does it produce

holocrine glands, usually associated with hair follicles. produces sebum which keeps hair/skin soft and waterproof

where are sebaceous glands not present

palms of hand and sole of feet

acne

disorder of sebaceous glands

another word for sweat gland

sudoriferous glands

what skin layer do sweat glands originate

deeper dermis or hpodermis

what are the types of sweat glands

eccrine/merocrine glands and apocrine

what sweat gland is most abundant

eccrine

eccrine sweat gland purpose

respond to elevated body temp. goal: produce sweat to keep body cool usually directly connectd to a pore

apocrine sweat glands location (in cell and on body)

usually attaches to a hair follicle, found in axillary and groin region. secrete by exocytoasis

mammary glands

produce milk

ceruminous glands

produce ear wax

what is body odor caused by

apocrine sweat glands

what pigments contribute to skin color

keratin, melanin, hemoglobin

what is heat a product of

cellular metabolism

what body cells are heat producers

skeletal muscle, cardiac muscle, cells of the liver