19 2018 What do you already know about the integumentary system Integumentary System Components Skin aka cutaneous membrane or integument Hair Nails Integumentary System Components ID: 703544
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Slide1
Integumentary system
Sept
19
2018Slide2
What do you already know about the integumentary system?Slide3
Integumentary System
Components
:
Skin (aka
cutaneous membrane
or integument)HairNailsSlide4
Integumentary System
Components
:
Skin (aka
cutaneous membrane
or integument)HairNails
Fun fact:
The skin is the largest organ in the body.
The skin of an average adult weighs more than 9
lbs
!Slide5
Integumentary System
FunctionsProtection
Thermoregulation
Excretion of wastes
Synthesis of vitamin D Slide6
Functions of Integumentary System
Protection
From mechanical, chemical, and thermal damage
Barrier of tough, keratinized cells
Pain receptors warn body of possible damage
From pathogens
Unbroken surface
Acidic secretions inhibit bacterial growth
Phagocytes ingest foreign material
From UV radiation
Melanin absorbs UV light and prevents it from reaching deeper layers
From desiccation (drying out)
Keratin and other substances keep skin fairly waterproofSlide7
Thermoregulation
How does the skin help us cool down?
How does the skin help us warm up?
Functions of Integumentary SystemSlide8
Thermoregulation
How does the skin help us cool down?
Evaporative cooling (sweating)
Increased blood flow through skin (increases heat loss)
How does the skin help us warm up? Goose bumps:
arrector
pili
muscles contract to pull hair upright, and add insulation to body
Decreased blood flow through skin (reduces heat loss)
Functions of Integumentary SystemSlide9
Excretion of wastes –
The sweat glands excrete metabolic wastes (urea, uric acid), salt, and lactic acid (in addition to water)
Synthesis of vitamin D
When UV light hits the skin, modified cholesterol molecules are converted into vitamin D.
Functions of Integumentary SystemSlide10
Quick Review
Turn & Talk (5 min), then share with class.Scholar on left …
Name the four major functions of the integumentary system.
Explain how the skin fights pathogens.
Scholar on the right …
Name the three components of the integumentary system.Explain how the skin allows us to thermoregulate.Slide11
Skin Structure
The skin is composed of two layers:
Epidermis –
made of
_______________ tissue
2) Dermis-
made
of
_______________ tissueSlide12
Skin Structure
The skin is composed of two layers:
Epidermis –
made of
epithelial tissue
2) Dermis-
made
of
dense connective tissueSlide13
Skin Structure
Fun fact:Blisters occur when friction causes the epidermis to pull away from the dermis.Slide14
Epidermis Structure
Epidermis is made of epithelial tissue.Quick Review:
What are the characteristics of epithelial tissue?Slide15
Epidermis Structure
Epidermis is made of epithelial tissue.Quick Review:
What are the characteristics of epithelial tissue?
Form continuous sheets, have cell junctions
Avascular
Apical side freeOther side attached to basement membraneRegeneration
Remembering these characteristics will help you understand the structure and function of the epidermis!Slide16
Epidermis Strata
The epidermis has multiple strata or layers.
Only the deepest layer contains actively dividing cells and melanocytes.
Why?
Because the deepest layer is closest to the blood supply.
As new cells form, older cells are pushed towards the surfaceSlide17
Epidermis Strata
As the cells are pushed away from the blood supply, they atrophy and flatten.The most superficial layer is made of the dry, keratinized membranes of skin cells.Slide18
Epidermis Cells
Two main cell types in epidermis:
Keratinocytes
Keratin-producing cells
Keratin is the protein that makes skin
tough and waterproof.Most abundant cell in epidermis
Melanocytes
Melanin-producing cells
Melanin is the brown-black pigment that is largely responsible for skin, hair, and eye color
Melanin absorbs UV light to product DNA from damageFound only in deepest layer of epidermisSlide19
Skin Color
Major determinants of skin colorAmount / type melaninAmount carotene (from fruits and veggies)Amount oxygen in blood
Adaptive significance
Trade off between UV protection and vitamin D productionSlide20
Dermis
The dermis is made of what tissue? Slide21
Dermis
The dermis is made of what tissue? Connective
(specifically, dense irregular)
Connective tissue cushions and binds things together. In the skin, the connective tissue holds together lots of different elements:
Exocrine glandsHair folliclesNerves and sense receptors
Blood vessels
The collagen and elastic fibers of the dermis give skin its strength and elasticitySlide22
Diseases & Disorders: Burns
First degree burn
:
only epidermis is damaged.
Second degree burn:
Damage extends partway into dermis.
Third degree burn
:
Damage extends all the way through dermis. Slide23
Diseases & Disorders: Burns
First degree burn
:
only epidermis is damaged.
Second degree burn:
Damage extends partway into dermis.
Third degree burn
:
Damage extends all the way through dermis.
Signs: red, swollen skin
Example: most sun burns
Will heal on ownSlide24
First degree burn:
only epidermis is damaged.
Second degree burn:
Damage extends partway into dermis.
Third degree burn:
Damage extends all the way through dermis.
Signs: red, swollen skin
Example: most sun burns
Will heal on own
Signs: blistering
Skin will heal with care
Diseases & Disorders: BurnsSlide25
First degree burn
:
only epidermis is damaged.
Second degree burn:
Damage extends partway into dermis.
Third degree burn
:
Damage extends all the way through dermis.
Signs: red, swollen skin
Example: most sun burns
Will heal on own
Signs: blistering
Skin will heal with care
Signs: blackened or blanched (gray-white) skin, lack of pain due to damaged nerves
Skin will not heal; grafts must be done
Diseases & Disorders: BurnsSlide26
Burned skin can no longer carry out its functions
Turn & TalkQuick review: What are the functions of the skin? Analyze: Which functions are most critical?
How do burns disrupt homeostasis?
Protection from abrasion / chemical damage / UV damage / pathogens / against
dessication
Excretion of wastes
Thermoregulation
Synthesis of Vitamin DSlide27
Burned skin can no longer carry out its functions
Most critically, skin can no longerPrevent loss of fluids and electrolytesFluid loss and electrolyte imbalance can cause kidneys to shut down and patients to go into shock due to low blood volume
.
Happens almost immediately, unless fluids are replaced.
Protect the body from pathogens
Infection becomes a major concern within 2-3 days following severe burns.
How do burns disrupt homeostasis?Slide28
Burned skin cannot
thermoregulate
.
Hypothermia becomes a problem.3
rd
degree burns cannot regenerate.
Scar tissue forms. Scar tissue does a poor job of
perfoming
the functions of skin, and if the scar
tissue is extensive, mobility may be affected.
Other complications of burnsSlide29
Exit Ticket
In a short paragraph explain how burn classification and severity is related to the structure and function of the skin.