What’s Up With That?

Think for a moment…  A suit of armor protected a knight from injuries in battle. Imagine what it would be like to wear a suite of armor. For one thing, it would feel very heavy. Also, you’d probably make a great deal of noise every time you moved. In some ways, your skin is like a suit of armor. It isn’t as strong, but it has many advantages over metal armor.

INTEGUMENT The Structure and Function of Skin

Integument  “Covering”  Includes skin & skin appendages  Glands  Hair  Nails

Functions of Skin  Protection  Mechanical  Pathogens  UV Damage  Chemical  Thermal  Dessication (drying out)

Functions of Skin  Temperature regulation  Excretion – perspiration eliminates salts & urea  Sensation –temperature, touch, pressure & pain  Vitamin D synthesis

Skin Structure (deep to superficial)

Hypodermis  Not part of skin, but anchors it to underlying organs  Mostly adipose tissue (fat) & other connective tissue  Responsible for most female curves

Dermis (still deep to superficial)  Dense connective tissue  Two layers:  Reticular layer – contains glands, blood vessels, & deep pressure receptors (Pacinian corpuscles)  Papillary layer – made of projections called papillae that cause fingerprints and contain: Pain receptors (free nerve endings) Touch receptors (Meissner’s corpuscles) Capillary loops

Epidermis  No blood vessels  Bottom layer is rapidly dividing  Top layer is all dead cells

The Big Picture

Questions to Consider  What is a blister?  Why doesn’t it hurt to shave? It takes off layers of cells every time.  Why don’t people bleed when they shave?  What is a tattoo?  People say “beauty is only skin deep”. Do you agree when nearly everything you see on a person is dead?