Integumentary System

groups of cells with similar structure and functions

• Epithelium: layers/cells of your skin, inside layers of digestive respiratory and excretory systems
• Connective Tissue: connects epithelium to the organs ex- skin to muscles
• Nervous Tissue: brain and white matter
• Muscle tissue: tissue for muscles (skeletal muscles, cardiac muscles, smooth muscles)

body converings, body linings, glands/glandular tissue

• protection from different things
• ---> ex- sunlight, invaders (bacteria), acids, bases
• absorption
• ---> small intestine, stomach, and alveoli in lungs
• filtration: epithelium filters out different things such as urine
• secretions
• ---> sweat

• cells very close together, no space between them
• tissue layer is always exposed to one free surface (ex. alveoli exposed to hollow opening in lungs)
• the lower surface is bound to a basement membrane
• avascular (have no blood supply)
• can regenerate easily if well nourished

• simple: one layer
• stratified: more than one layer
• pseudostratefied: fals stratefied layer, looks like many layers but is one

• squamous: flattened
• cuboidal: cube shaped
• columner: column like

• singel layer of cube like cells
• common in glands and their ducts
• forms walls of kidney tubules
• covers the ovaries

• epidermis
• dermis

• 1. It is an impermeable membrane- doesn't allow things in or out, advantage of this is it doesnt let water out, keeping you hydrated
• 2. insulates and cushions the deeper organs
• 3. protects against mechanical damage ( bumps & cuts)
• 4. protects against chemical damage (acids and bases) ( secretions on your skin are slightly acidic so it can neutralize slight bases)
• 5. protects against thermal damage (heat and cold, like frostbite) and ultraviolet rays (like a sunburn)
• 6. excretion (through your sweat you get rid of urea, salt and water)
• 7. manufactures/makes protiens for immunity and vitamin D (sunlight helps this)
• 8. contains nerves that sense pain, touch, pressure, hot and cold (all different receptors)

• made up of stratified squamous (many flat layers squished) epethilium
• Divided up into 5 layers

• Stratum Corneum
• Stratum Lucidum
• Stratum Granulosum
• Stratum Spinosum
• Stratum Basale

dead cells because the nutrients can't diffuse far enough to keep them alive

• top layer
• made up of 20-30 layers of cells
• 75% of all the layers of your skin is stratum corneum

• dead clear cells and can easily be seen in the palms of your hand and soles of your feet (thicker in these areas)
• 2nd layer

• some alive cells, some dead (transition)
• filled with keratin (a protien) that fills up the layers above it (lucidum and corneum)
• keratinocytes die

• single layer of cells
• cells are alive
• recieves neutrients to stay alive from stratum basale

• also called germinativum
• stem cells that become the other cells
• only layer that recieves nutrients directly from the blood (those nutrients diffuse into the spinusom and some granulosum which keeps them alive)

the cells move up. basale become spinosum which mature into granulosum then die and become lucidum which flake off as corneum

yes but only at one point to deliver neutrients

• millions
• btween 25 and 45 days ALL of your skin cells are replaced

cells in the epidermis that make keratin

a protien that protects the dna of the neucleus

• a pigment that ranges from yellow to brown to black
• can determine skin color

• below the epidermis
• made up of dense connective tissue
• vascular region
• major skin area where derivatives (hair, nails) reside
• when tanned becomes leather, provides mechanical strength to the skin

• papillary region
• reticular region

uneven, fingerlike projections from the superior surface of the dermis

• capillaries that bring blood and nutriends to the epidermis
• pain receptors called free nerve endings
• touch receptors called meissner corpuscles

papillae push up epidermis to make your fingerprint, see drawing

no. not even twins. in the mothers womb, fluid moves around moving one twins fingerprint one way and the others the other way

• the deepest skin layer
• contains: blood vessels, sweat glands, and deep pressure receptors called pacinian corpuscles

• collagen fibers
• elastic fibers

• make the dermis very tough, not easily broken
• little pieces of protien that hold it together
• it binds to water to keep your skin hydrated

allow the skin to stretch and then return to its orignial place

stretchy but strong

forms when the dermis and the epidermis separate. they pull apart and the space between where they should meet is filled with fluid

• NOT part of the skin
• below the dermis
• layer filled with fat and connects the dermis to the organs underneath

• 3 pigments
• --->melanin
• --->carotene
• --->hemaglobin

• yellow, reddish brown, or black pigment in epidermis
• --->freckles or moles are collections of melanin
• most melanocytes are found in the stratum basale
• most responsible for the color of dark skinned people
• provides a natural sunscrene
• phagocytized by keratinocytes

• orange to yellow pigment in the stratum corneum (1st layer)
• provides an orange cast to skin

• a red to maroon color, depending on the oxygen level
• inside of RBCs in your blood vessels
• most responsible for the skin color of caucasions

combine to make your skin color

• emotional stimuli
• --->can also indicate illness

• Redness or Erythema
• Pallor or blanching (turning white)
• Jaundice (yellow)
• Bruises or black-and-blue marks

this can occure if you're embarrassed, if you have a fever, hypertension (high blood pressure), inflammation, or allergy

from fear or anger, anemia (lacking iron and having trouble moving oxygen or bloodflow is restricted to an area)

usually a signal of liver disease, excess bile is absorbed in the blood

where blood has escaped the circulatory system and fills a tissue place called a hematoma (or bruise). can indicate a deficiency of vitamin C if you pruise easily. can also indicate hemophilia

• Cutaneous glands
• Hair/Hair Follicles
• Nails

• glands in the skin
• all exocrine (they have a space and a tube or duct leading to the surface)
• two groups

• Sebaceous Glands
• Sweat Glands

• secrete oil that covers all parts of the skin escept the souls of your feet and palms of your hands
• keeps skin soft and prevents it from becomming brittle
• produces antibacterial chemicals to fight infection

• produce sweat
• approx 2.5 million glands in the body
• 2 types

• eccrine
• apocrine

• produce a clear liquid made up of water, salt, vitamin c, and matabolic waste such as urea, uric acid, ammonia and lactic acid
• maintains body temp
• pH between 4 and 6 (acidic) helps burn through membranes of harmful bacteria

• found in the axillary area (armpits) and genital areas
• secrete fatty acids and protiens which color it yellow or a clowdy milky white
• sweat is colorless and odorless unless bacteria are living on the secretions (this is B.O.)

• protection from bumps
• shields eyes from dust and particles
• keeps out particles from the respiratory sysem (nose hairs)

• hair is made up of dead cells
• bottom part is alive until you die
• dead cells build up over time making your hair grow longer
• has 3 layers

• medulla: inner layer
• cortex: middle layer
• cuticle: outside, single layer that overlaps and prevents dehydration

• oval shaft: hair will be smooth, silky, and usually wavy
• flat or ribbon like shaft: curly or kinky hair
• round shaft: straight and course

muscles that contract to make hairs stand on end (goosebumps)

scale like epidermal cells

a root that is embedded into the skin, also dead cells except for root which is alive

they are colorless but appear pink because of the blood vessels beneath

• Athlete's foot
• Boils and carbuncles
• Cold sores
• Contact dermatitis
• Impetigo
• Psoriasis

• itchy red impealing skin
• usually between the toes
• fungus
• it would be easier to treat if it was a bacteria b/c fungi cells are similar to your own so you have to kill some of your own cells to get rid of it

• inflammation of the follicles and sebaceous glands
• caused by a bacterial infection, usually staffaureus

• also called fever blisters
• itchy and stingy
• fluid filled blisters caused by herpes simplex virus
• activated by uv light, fever, or emotional upset

• itchy redness and swelling of the skin that turns into blisters
• caused by exposure to chemicals that cause an allergic reaction (ex- poison ivy)

• pink water filled spaces or cracks that develop a yellow crust on the outside and eventually burst
• caused by staff

• chronic red epidermal legions covered by dry slivery scales
• unknown cause
• can be triggered by trauma, infection, hormonal change, stress

eccrine glands become active

basal cell carcinoma

milia

Skin cancer that appears most often as scaley, reddened papule that gradually form a shallow ulser with a firm raised boarder

Psoriasis

growth zone at the inferior end of a hair follicle

medical term for a bedsore

the part of hair that is enclosed in a follicle

• downy type hair that covers a fetus during the 5th and 6th months
• is shed at birth

central core of hair

Outermost covering of hair follicle

epithelial and connective tissue

cold and sores

• dehydration
• infection

contraction to produce movement

irritability and conductivity

• protection
• support
• binds body tissues together
• usually well vacularized and has extensive intercellular matrix

• protection
• absorption
• filtration

prevents the skin from soaking up moisture like a sponge

a modification of the epidermis

subcutaneous (hypodermis) connective tissue

dehydration

smooth muscle tissue

Skeletal, smooth, and cardiac muscle tissue

the dermis

cutaneous membrane

• fat tissue
• forms subcutaneous connective tissue beneath the skin

inflammation of the sebaceous glands

cardiac muscle tissue

axillary and genital areas

stratum basale

an increased amount of melanin

endocrine

epidermis

papillary