Transcript AP Integument Main

Integumentary System
Derm and integere = 'to cover‘
hair, scales, feathers, and nails
Largest organ - 16% body weight
1.5-2m2 surface area
FYI
In 2 square inch …
20 blood vessels, 65 hairs and hair muscles
78 nerves, 78 heat sensors, 13 cold sensors
160 sensors for pressure, 100 sebaceous/oil
glands, 650 sudoriferous/sweat glands
1300 nerve endings, 19,500,000 cells
0.5 million cells dying and being replaced
Functions
Protection: barrier, shock absorber
Water balance: prevents water loss,
absorption
Thermoregulation: evaporative cooling by
sweating, vasoconstriction/vasodilation,
Why?
Waste disposal: oil, water, Na+, CO2, etc.
Receptor organs: touch, pain, heat, cold,
pressure
Vitamin D production
Layers of the Skin
Epidermis (epithelial cells); avascular; stratified squamous
Dermis (tough, leathery fibrous connective tissue; only
part that is vascularized) - also called the corium
Subcutaneous (hypodermis)
Not skin
Adipose/areolar connective tissue
Stores fat
Anchors skin to underlying structures
Allows skin to slide freely
Shock absorber, insulator
Thickens with weight gain
Layers of the Epidermis:
Types of Cells in Epidermis:
Keratinocytes –
protection from elements
millions rubbed off every day
Melanocytes –
pigment cells
Langerhans cells
macrophages that activate immune system
Merkel cells
sensory nerve receptors
Dermis = True skin
Cells –
fibroblasts, macrophages, mast cells,
WBCs
Fibers –
collagen, elastin, reticular
loss of elastin/subcut fat?
Arterioles, Venules & Capillaries
Lymphatic vessels
Nerves, Hair shafts/follicles
Sensory receptors
Layers of the Dermis
Papillary layer
many blood vessels & capillaries
pain/touch receptors
Meissner’s corpuscles - touch receptors
dermal ridges – friction/gripping/prints
Reticular layer
elastin
80% of dermis
collagen
Lines of cleavage/tension
longitudinal - head and limbs
circular - neck and trunk
Parallel incisions heal faster
Common Problems
of the Dermis
Stretch marks –
tears in
dermis
silvery white
scars
Blister –
separation
of layers by
fluid
Skin Color
Melanin
freckles, albinism,
vitiligo
Carotene
precursor to Vitamin A
Hemoglobin
light skinned people?
Used in diagnosis
cyanotic; jaundice;
erythema
Accessory Organs
Develop from
epidermis of
embryo
Hair
Glands
Sebaceous,
Sudoriferous,
Ceruminous
Nails
Hair
Questions to think about:
• Why does our hair turn grey?
• Does cutting your hair make it grow
faster?
• What causes goose/chill bumps?
• Where on our body do we not have hair?
• How often does our hair rest & grow?
• What causes male pattern baldness?
• Why do we have different color hair?
Oil Glands = Sebaceous Glands
• What does a gland
do?
• Sebac = greasy
• What is sebum?
• Blackhead/pimple/
boil?
• Dermabrasion?
Sweat glands = Sudoriferous Gl.
• Apocrine vs. Eccrine?
• Apo = from
• Eccrine = secrete
outward
• Sudori = sweat
• Apocrine – pits and
privates
• Eccrine – sweat pores,
forehead, palms and
soles of feet.
Wax Glands = Ceruminous Glands
• Where are
they?
• What do they
do?
• What should
you do if you
produce a
large amount
of cerumen?
Nails
• Tightly packed
epidermis
• Matrix, root,
cuticle, lunula
(little moon), nail
body and free
edge
• Protection,
scratchin’ and
pickin’ yur nose.
Why do we need fingernails?
How does aging affect the
Integumentary System??
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Acne
Fibers in dermis affected =Wrinkles
Immune response?
Drier & thinner skin
Gray hair & atypical skin pigmentation
Decrease in nail & hair growth
How does the skin help regulate
body temperature? Hot Cold
Baby!!!
1. Thermoreceptors stimulated
2. Input to Hypothalamus
3. Sweat glands stimulated
4. Evaporation causes cooling
5. Temp returns to normal
- Or + feedback?
How does the Integumentary
System help with homeostasis?
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Skeletal
Muscular
Nervous
Endocrine
Cardiovascular
• Lymphatic/
Immune
• Respiratory
• Digestive
• Urinary
• Reproductive
Burns
• What are 4 causes of burns?
• What are the 3 types of burns &
how are they different?
• What is the rule of nines?
Rule of Nines
Skin Cancer
• What are 3 types?
• What is the ABCD rule for
melanoma?
Hemangiomas
Impetigo
Poison Ivy
Do you suppose he experienced pruritis?