module 1 integ term 4

Question 1

why is skin so important?

Answer 1

largest single organ
15-20% body weight
1.5-2m^2 surface area
neglected organ

Question 2

integ, integumentum is latin for

Answer 2

Covering

Question 3

integumentary / cutaneous

Answer 3

yeah

Question 4

major function of skin

Answer 4

protect from infection and injury
prevent loss of body fluid
regulate body temp
receives external stimuli - through touch
indicator of internal events - fever makes you look flush
determines identity - scars / pimple etc

Question 5

two very important types in skin, they are

Answer 5

epithelial tissue
connective tissue

Question 6

3 main layers of skin

Answer 6

Epidermis
Dermis
Hypodermis

Question 7

what type of epithelium is epidermis considered?

Answer 7

stratified squamous keratinized epithelium

Question 8

what kind of cells are in the epidermis / stratified squamous keratinized epithelium ?

Answer 8

cells called keratinocytes MAIN CELLS
melanocytes - pigment producing cells
langerhans cells - signals the immune system
merkel cells - associated with sensory nerve endings

Question 9

what are the MAIN MAIN kind of cells are in the epidermis / stratified squamous keratinized epithelium ?

Answer 9

KERATINOCYTES

Question 10

another way (cool scientific way) to refer to the epidermis is….

Answer 10

stratified squamous keratinized epithelium

Question 11

we know that there are two very important types of tissue involves with integ which are connective tissue and epithelial tissue and we know there are 3 layers to skin which are epidermis dermis and hypodermis but what are the two different types of epidermis?

Answer 11

thick and thin epidermis

Question 12

Thick epidermis is found on where?

Answer 12

palms and soles of feet
400 to 1400 um
has 5 layers

Question 13

thin epidermis is found where?

Answer 13

everywhere but palms and soles of feet
has 75 to 150um
has 4 layers

Question 14

The stratum basale, what is this ?

Answer 14

the very lowest layer of the epidermis

Basement layer

Question 15

stratum basale components?

Answer 15

basal layer, stratum germinativum
single layer of BASOPHILLIC columnar or cuboidal cells
stems cells for keratinocytes
contains filaments called keratins

Question 16

Keratinocytes are the name of which type of cells

Answer 16

Epidermal cells

keratinocytes = epidermal cells

Also called keratinocytes because they contain filaments called keratin

Question 17

your epidermis is constantly creating more _______

Answer 17

keratinocytes / epidermal cells / things made of keratin

Question 18

BASOPHILLIC COLUMNAR / CUBOIDAL CELLS

Answer 18

STEM CELLS for keratinocytes

Question 19

STEM CELLS, WHAT THEY ALL ABOUT ?

Answer 19

SELF RENEW AND DIFFERENTIATE TO OTHER TYPES OF CELLS

Question 20

THE BASOPHILLIC COLUMBAR / CUBOIDAL CELLS OF THE STRATUM BASALE DO WHAT ?

Answer 20

THESE CELLS ARE STEM CELLS AND WILL ULTIMATELY BECOME THE KERATINOCYTES OF THE LOWEST LAYER IN THE EPIDERMIS

Question 21

KERATINONCYTES MIGRATION COMPONENTS

Answer 21

new keratinocytes arise via mitotic division
they move up to the next layer
upward migration terminates when the cell becomes a mature keratinized cell and is sloughed at the surface

Question 22

one level up from the basement - stratum spinosum
basement layer of epidermis - stratum basale

the stratum spinosum components

Answer 22

knowns as the spinous layer
thickest layer of the epidermal layers
flattened with a central nuclei

the cells are becoming a little bit more flat
the nucleus is becoming a bit more centralized

Question 23

cellular aspects of stratum spinosum

Answer 23

cells actively synthesize keratin filaments
filaments form bundles called tonofibrils
cytoplasm is drawn into the short cellular extensions around the tonofibrils called spines

the spinous layer of the epidermis has got them cells that make more keratin and for them into bundles and they make a shape around them with extension that appear to be spines that bring in cytoplasm

Desmosomes are also cells in the stratum spinosum

Question 24

Desmosomes are cells in which layer of the epidermis?

Answer 24

Desmosomes are in teh stratum spinosum
disc shaped structure on a cell
matched to another disc shaped structure on an adjacent cell
provides adhesion to resist friction

when you rub your skin, your skin doesn’t fall off because of these - your epidermis would just fall apart

Question 25

Most diseases of skin derive from the stratum basal and the stratum spinosum , t or f

Answer 25

true

Question 26

Basal cell carcinoma

Answer 26

* Slow growing tumor * Does not invade blood or lymph vessels * Causes significant local destruction

Question 27

Squamous cell carcinoma

Answer 27

* Can be in situ, or invasive can be localized or invasive

Question 28

what percentage of cancer in adults is skin cancer?

Answer 28

1/3

Question 29

most skin cancer comes from which two layers of epidermis ?

Answer 29

bottom two and they are both slow going, so usually can be noticed early on

Question 30

Psoriasis

Answer 30

* Autoimmune disease * Increase in cell proliferation in the stratum basal and stratum spinosum * Decrease in the cycle time * Results in an increase in epidermal thickness * Abnormal keratinization Psoriasis = I makey a lot keritinocytes I flakey a lot skin autoimmune

Question 31

next level up - stratum granulosum next level up - stratum spinosum (spinous) basement - stratum basale stratum granulosum components

Answer 31

Most superficial of the non-keratinized portion of the epidermis * 3-5 layers of polygonal cells * Cytoplasm is filled with intensely basophilic masses * Keratohyaline granules

Question 32

the only layer seen in THICK skin is the that STRATUM ______

Answer 32

LUCIDUM STRATUM LUCIDUM * Only seen in thick skin * Thin translucent layer of flattened cells * Cytoplasm consists of densely packed keratin filaments

Question 33

Stratum LUCIDUM

Answer 33

* Only seen in thick skin * Thin translucent layer of flattened cells * Cytoplasm consists of densely packed keratin filaments your dumb if you think stratum lucidum is anywhere else other than palms and soles I will do a palm to my face or stomp on the soles of my feet if you think the stratum lucidum is anywhere else other than my palms and the soles of my feet

Question 34

top floor - stratum corneum level up - ONLY in soles of feet and palms - Lucidum level up - stratum granulosum level up - stratum spinosum Basement layer - stratum basale stratum corneum components

Answer 34

* 15 to 20 layers * Flattened, non-nucleated keratinized cells * Cytoplasm is filled with keratins (structural proteins) * Cells at the surface are continually shed

Question 35

A: excuse me your epidermis is showing.... B: dont you mean my stratum _________ ;)

Answer 35

corneum the corniest of all jokes can now be even cornier when you know the most outer layer of the epidermis is the stratum corneum

Question 36

lorello talking about the top layer of epidermis ....

Answer 36

at this point, the cells are very very flat, they lost all of their cell organelles, there is no nucleus anymore, the cytoplasm of cell is just filled with keratins, and here is where the cells are continually shedding and coming off at the top

Question 37

Epidermal Derivatives - aligned with epidermal cells they house epidermal step cells Epidermal appendages Epidermal other things

Answer 37

* Hair follicles deep within the dermis * Sweat glands * Sebaceous glands deep within the dermis * Nails

Question 38

other cells of epidermis (non keratinocytic)

Answer 38

melanocytes * Specialized cell found among the basal layer and hair follicles * Produce melanin granules * Protects against UV radiation Dentritic - langerhans cells Merkel (tactile) cells Keritinocytes are the big dog but you got the germans, with their ex leader woman - merkel

Question 39

Melanocytes

Answer 39

* People with ancestral origins near the equator produce melanin granules more rapidly and accumulate them in keratinocytes more abundantly * Tanning * Physiochemical reaction darkens preexisting melanin * Rate of melanin synthesis increases * Specialized cell found among the basal layer and hair follicles * Produce melanin granules * Protects against UV radiation

Question 40

Malignant melanoma - cancer of melanocytes - in BASEMENT layer of epidermis - very close to vascular in the dermis !!!!!

Answer 40

* Invasive tumor of melanocytes * Penetrates the basal lamina and enter the dermis * Invade the blood and lymphatic vessels * Easily distributes throughout the body

Question 41

DENTRITIC (LANGERHAN’S) CELLS

Answer 41

* Dense network throughout the epidermis * Bone marrow derived * Capable of binding and processing foreign body * Presents antigens to T- lymphocytes * Microorganisms cannot penetrate epidermis without triggering immune response * trigger immune response (skin protectors ?) Langerhans have their HANDS in everything from processing foreign bodies, presenting antigens to T lymphocytes MADE FROM BONE MARROW

Question 42

Merkel (tactile) cells - bottom of epidermis as well

Answer 42

* Function in cutaneous sensation * Mechanoreceptors in the stratum basal in areas of high sensitivity * Associated with the terminal bulb of an afferent myelinated nerve fiber The ex leader woman of germans are always touching people merkel cells big on tactile

Question 43

* Steven’s Johnson Syndrome (SJS) * Toxic Epidermal Necrolysis (TENS) (worse version of SJS)

Answer 43

* Severe cutaneous hypersensitivity (allergic reaction) * Keratinocyte death * Epidermal sloughing (falls off/dies) in case of rash please call your physician !!! This is why !!!