integumentary system exam 2

what is an organ system

a group of organs that operate collectively to perform a specific task/ function

what 2 things does the integumentary system consist of

• the skin

• the skin derivatives

what is the largest organ of our body

skin

dermatology

the study of the skin

what are the 4 skin derivatives

• hairs

• nails

• glands

• sensory receptors

what are the 3 regions of the skin

• epidermis

• dermis

• hypodermis

location of epidermis

superficial

what tissue if the epidermis made of

stratified squamous ep tissue

stratified squamous ep tissue is or is not vascularized (containing blood vessels)

IS NOT

what is the function of the epidermis

protection

where is the location of the dermis

deep/ below epidermis

what tissue is the dermis made of

fibrous connective tissue

• specifically dense irregular connect tissue

is the dermis vascularized

YES- contains blood vessels

what are the 2 layers of the dermis

• papillary layer

• reticular layer

what is the function of the dermis

• support

• nourishment from blood supply

location of the hypodermis

deep/below dermis

is the hypodermis considered a skin portion

IS NOT

what tissue does the hypodermis consist of

adipose tissue

the hypodermis the superficial covering of ______ aka _______ ________

• muscle

• superficial fascia

what affect does age have on the hypodermis. why?

as you age, gets thicker

• increase lipid deposition in adipose cells

function of hypodermis

protection and cushion

is the epidermis thick or thin

can be either depending on the location

how long does it take the epidermis to go from division at the bottom to being sloughed off (shed from the body)

2 weeks

we have a completely new epidermis ever how many days

25-45 days

what layers of the thin skin composed of

• stratum corneum

• stratum granulosum

• stratum spinosum

• stratum basale

stratum corneum

• # of layers

• living or dead

• 20-30+

• dead (the only dead layer of the skin)

what protein is the stratum corneum filled with

keratin

what is the stratum corneum’s function

protection

stratum granulosum

• # of layers

• living or dead

• 3-5

• living (last living layer→ “grandma”)

what is the last living layer in the epidermis

stratum granulosum

the stratum granulosum is known as the ____ layer

granular→ accumulates granules in the cell

what are granules

cells that contain a large number of vesicles inside of them

what are the 2 types of granules

• keratohyalin granules

• lamellated granules

what protein do keratohyalin granules contain

keratin

what do lamellated granules contain

glycolipids

the hydrophobic lipid content in the lamellated granule helps to _____ the skin and reduce desiccation (loss of water in the body)

“waterproof”

stratum spinosum

• # of layers

• living or dead

• several

• living

the stratum spinosum contains ___ cells

prickle

the stratum spinosum contains what that are found in between cells

desmosomes

• button-like junctions that anchor the cells together by their microfilaments / microtubules

as the cell dries out in the stratum spinosum, the desmosomes pull on them, making them appear

shiny

stratum basale

• # of layers

• living or dead

• 1

• living

which layer is the location of cell reproduction

stratum basale

what is the stratum basale also known as

stratum germinativum because these are the cells that are dividing to produce new cells

what is the only difference between thin and thick skin

thick skin has an extra layer called the stratum lucidium

how does the stratum lucidum appear on images

clear

where is the stratum lucidum found

where skin is really thick and has high friction

example where stratum lucidum is found

• palms of hands

• soles of feet

provides increase protection

what is the difference in the stratum corneum in thick vs thin skin

the stratum corneum in thick skin is thicker

does thick skin contain hair follicles

no

which dermal layer is top/bottom

papillary= top

reticular= bottom

what are the extensions of the papillary region that extends into irregualtion of the epidermis

dermal papillae

irregularity in the papillary region helps what

keep the 2 layers from separating

what connective tissue is the papillary made of

areolar/loose connective tissue

what is the papillary funciton

strength and flexibility

what tissue is the reticular region made of

dense irregular connective tissue

what are the cells found within the epidermis

• keratinocytes (most common)

• melanocytes

• Langerhans

• Merkel cell / disks

keratinocytes make up most of the

epidermis

keratinocytes are cells that undergo

keratinization

keratinocytes begin as ____ cells at the stratum basale of the epidermis undergo the process of keratinization

living

steps of keratinization

1. produce protein called keratin

2. keratin accumulates inside the cell as it moves UP the layers of the epidermis

3. cells DIE as they move toward the surface of the skin

4. these cells then get sloughed off

function of keratinocytes

protection

do melanocytes make up a large or small portion of the cell

small

where are melanocytes found

deep in the epidermis

what skin pigment does melanocytes produce

melanin→ gives skin color

melanin pigment becomes a ______ inclusion

cytoplasmic (a stored substance inside the cytoplasm that is not a cell organelle)

the amount of melanin the cell decides to produce is stimulated by what two things

genetics and sunlight

what is the melanocytes’ function

protection against harmful UV radiation

Langerhans cells are a derivative of

bone marrow

• meaning they start off as bone marrow, separate from bone and end up in the epidermis

• site of production of blood cells

what are Langerhans cell’s function

immunity

• prevents things from entering the body by binding to foreign substances and destroying them

where are the Merkel cell/ disc located

at the epidermal-dermal border, but on epidermal side

Merkel cells are sensory cells that detect ____ ______

light touch

• like when a bug crawls up your leg

what 3 things are involved in the development of integument

• ectoderm

• mesoderm

• hypoderm

ectoderm is developed where

epidermis

• stratified squamous ep t

mesoderm is developed where

dermis (fibrous connective tissue)

hypoderm is developed where

hypodermis (adipose connective tissue)

all connective tissue comes from what embryonic germ layer

mesoderm

skin color is determined by the combination of how many pigment

3

what are the 3 different pigments

• melanin

• carotene

• hemoglobin

racial differences are accounted for by the different ____ of each pigment

ratios

where is melanin located

epidermis

what cell is melanin produced by

melanocytes

melanin is triggered by what

UV radiation

melanin gives a darker or lighter color

darker

describe the melanin production process

involves the enzyme Tyrosinase→ located in melanocyte

• Tyrosinase is activated by UV radiation/sunlight

• Tyrosinase catalyzes the conversion of tyrosine (amino acid we get from the food we eat) to melanin (the protein)

• melanin accumulates as a layer of protection to block rays of sun from damaging underlying cells

tanning is a ___ ____ which keeps us from damaging the cells of active tissue

protective mechanism

where is carotene located

in the dermis

what color does carotene give

yellow/orange

accumulation of carotene depends on your

diet

• carrots and sweet potatoes

where is hemoglobin located

dermis

• within the blood in the capillaries of the dermis

what color does the hemoglobin give

blood red

what color does hemoglobin give the skin

pink

melanin and carotene ____ the effects of hemoglobin

mask

what are the 2 skin surface features

• ridges

• grooves

where on the body would u find ridges

fingers and toes

ridges are found in the ____ layer but cause superficial layers in the epidermis that we see

dermal

• they push the epidermis up and give us these ridges

what can ridges do for us

increase grip or friction

• allows us to grab and hold things

the pattern of ridges are _______ determined and are ____ to each person

genetically, unique

• Whorl = swirl

• Delta = triangle

• used in forensic id via fingerprints

what shapes are grooves on the skin

diamond

grooves are at the _____ where hair is growing

intersection

grooves are a remnant of what

that the skin used to be covered in scales