Transcript Integumentary2 - Advanced Health Care Home

The Integumentary System
AHCP
SOME FACTS ABOUT THE
SKIN THAT YOU ARE IN…

Its Waterproof, Stretchable,Washable, yet
Tough!

Its automatically repairs small cuts, rips &
burns & is guaranteed to last a lifetime

It weighs 7% of your body weight!
Functions of the Integumentary System
1. Protection: provides 3 types of barriers
A. Chemical: acid secretions slows bacterial growth
(ring tarnish!)
B. Biological: Macrophages = wbc’s patrol skin
C. Physical barriers: few things able to enter:
Some Fat-soluble substances
 Poisons (poison ivy)
 Solvents- paint thinner
 Heavy metals- lead & mercury
FYI: Transdermal patches are soaked in oils/solvents to carry drug
Across - nicotine, birth control & motion sickness!

Functions
2. Temperature Control
3. Makes Vitamin D - sunlight converts
cholesterol in dermis to Vit. D3 which is
needed for calcium uptake
4. Sensation - touch, pressure, pain & temp
5. Storage - fats
6. Excretion (wastes) & Secretions (milk)
What Is The Structure of Skin?
3 Layers:
 Epidermis
– Composed of epithelial tissue (stratified squamous)
– avascular

Dermis – underlies the epidermis
– Tough leathery layer composed of fibrous connective tissue
– Good supply of blood

Hypodermis (a.k.a subcutaneous layer -not considered skin)
– Made of adipose and loose connective tissue
– Stores fat, anchors skin, protects against blows
Epidermis
Dermis
Basement membrane
What are the different types of
cells in the epidermis?
1. Keratinocytes

Make the protein keratin =
tough & water resistant
Are formed in lowest levels &
push up by production of new cells
below

 Become dead and scale-like,
millions rub off everyday
FYI: Everything you see on a person is dead! Outer
20-30 cells thick. Average person sheds 40 pounds
of these in a lifetime!
What are the different types of
cells in the epidermis?
2. Melanocytes
 Make pigment melanin (melan = black)
 Absorbs ultraviolet light so skin is not
melanocyte
damaged
Melanin in
keratinocytes
What are the different types of
cells in the epidermis?
3. White blood cells
 They Macrophages,
which patrol & eat
bacteria/viruses
Langerhans’
cell
What are the different types of
cells in the epidermis?
4. Sensory Cells
 Connected to nerve cells
from dermis
 Sense touch.
Characteristics of the Dermis

Connective tissue has lots of collagen & elastic
fibers - gives skin strength

Thickest =

Thinnest = Eyelids

Extensibility = able to stretch (elbow skin)

Elasticity = able to return to its original shape after
extension/contraction (pregnancy & swelling)
Palms/soles
More Characteristics…
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Sense Receptors:
touch & pressure receptors

Ridges formed from papillary layer form
finger prints.
http://bio.rutgers.edu/~gb102/lab_5/104bm.html
What are the major structures
in Dermis?

Sweat glands
Sebaceous
Hairs
Nails
glands
Sweat Glands
1. Common sweat (merocrine)
 Watery sweat
 Heat & waste loss (all over skin - lots on palms/soles)
2. “Funky” sweat (apocrine)
 Milky/yellow thick sweat - thought to be scent glands
 Starts at puberty
 Armpits & groin
3. Ear wax! (ceruminous)
4. Milk (mammary)
Sweat Glands
1. Merocrine (common sweat glands)
 Watery sweat
 Heat & waste loss (all over skin - lots on palms/soles)
2. Apocrine (“funky”)
Sweat glands
Sebaceous Glands

Sebum = oil - around hair follicles, none on
palms/soles
 Softens and lubricates hair and skin
 Slows water loss and kills bacteria

Blackheads - built up sebum

Pimples - Built up sebum is a nutrient for
bacteria (puss!)
Sebaceous Glands
Hair

Made of dead keratinized skin cells

2 parts = shaft & root
 Function = Protection!
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FYI on Hair:
 You have about 100,000 hairs on your head
 You lose about 100/day
 It grows ~0.5 in/month - goes through cycles
 Hirsutism = excessive hair growth (often in
women due to disease)
Hair
 You have about 100,000 hairs on your head
 You lose about 100/day
 It grows ~0.5 in/month - goes through cycles
 Hirsutism = excessive hair growth (often in
women due to disease)
Hair Follicles
Hair Follicles
NAILS
FYI: Nails & Hair DON’T grow after death - skin just shrinks!

A scale-like modification
of the epidermis
 Made of tightly
compressed keratinized
cells
 Useful tools to pick up
small objects or scratch an
itch.
 Nail matrix is the region
responsible for nail growth.
What causes the color of
skin?

3 pigments contribute to skin color
1. Melanin
Range in color from yellow to reddish-brown to black
 Everyone has the same # of melanocytes but make
varying amounts & colors
 Sunlight increases production!
 Clusters create moles & freckles
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2. Carotene-yellow to orange pigment found in foods.
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Most in the palms or soles.
3. Hemoglobin- Red blood (from dermal
layer)gives a pinkish hue to fair skin
Aging Skin (A billion dollar
industry!)

Major Age-Related Changes
– Injury and infection increase
– Immune cells decrease
– Sun protection diminishes
– Skin becomes dry, scaly
– Hair thins, grays = loses melanin & fills with air!
– Sagging, wrinkles occur
– Heat loss decreases
– Repair slows
Skin Injury & Repair
Skin Injury & Repair
Skin Cancer

Benign lesions such as warts and moles are
not serious.

Malignant tumors can start on the skin and
invade other body areas.
• Crucial risk factor- overexposure to UV radiation
Types of Skin Cancer

Basal cell carcinoma- most common, 30% of all
white skin people get it.
– 99% curable if caught early
– Dome shaped nodules that form an ulcer in the center.

Squamous Cell carcinoma–Grows rapidly and metastasizes if not removed
–Small red rounded elevation on the skin
Basal Cell Carcinoma
Squamous cell carcinoma
Lesion removed from patient
Basal Cell Carcinoma
Skin Cancer Types cont.
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Melanoma
– Cancer of melanocytes (very dangerous)
– 5% of skin cancers but rising fast
– Can arise from preexisting moles
– Appears as a spreading brown or black patch
– Chance of survival is poor if the lesion is
greater than 4 mm thick
Melanoma
What is the ABCD rule?

Used for recognizing melanoma
Second-degree burns
Third-degree burn