Transcript Skin as an organizing model

Skin as an organizing model
What is it? (Anatomy)
What does it do? (Physiology)
What is it made of? (Histology)
Where does it come from?
(Embryology)
Frolich, Human Anatomy, Skin
What is it (anatomy)?
• Outer covering of body
• Keratinized
– Hair—head, pubic regions
– Nails—fingers, toes
• Divided into segments called dermatomes
(“Zebra-man”)
– CE (clinical example): Shingles
Frolich, Human Anatomy, Skin
What does it do (physiology)?
• [brainstorm]
Frolich, Human Anatomy, Skin
What does it do?
• PROTECTION
– Air = desiccation
– Water = bloating/”pruning”
– Sun/u-v = burns
– Cold/heat = frostbite/heat
stroke/thermoregulation
• STRUCTURAL
– Integrity of body
– Muscle attachment
Frolich, Human Anatomy, Skin
How does it do it?
• PROTECTION (mostly epidermis)
– Desiccation—keratin, lipid layer
– Water = keratin, lipid layer
– Sun/u-v = role of pigment/melanin
– Cold/heat = surface blood vessels
• STRUCTURAL (mostly ddermis)
– Integrity—Dermal layer has network of tough
collagen fibers in connective tissue
– Sub-dermal layer where muscle tendons insert
Frolich, Human Anatomy, Skin
What is it made of?
(histology—study of tissues)
Layers of skin are two
fundamental types of
tissue organization
– Epidermis = epithelium
– Dermis = connective tissue
Frolich, Human Anatomy, Skin
Frolich, Human Anatomy, Skin
Epidermis—a stratified epithelium
Frolich, Human Anatomy, Skin
Dermis—connective tissue substrate
Frolich, Human Anatomy, Skin
Skin is really an organ…
• Made up of two very different basic tissue
types
– the epidermis which is composed of epithelial
tissues
– The dermis which is composed of connective
tissue
On to a review of basic tissue types…
Frolich, Human Anatomy, Skin
(“Tissues” presentation)
Where does it come from (Embryology)
After review of basic tissue types, on to
introduction to embryology and basic
human body plan
– outer and inner tubes of body (skin as
epithelial layer and part of skeletal structure of
outer tube)
– Segmentation (skin reflects basic segmented
organization of human body seen in
vertebrae, ribs, nerves, etc.)
(“Basic Human Body Plan” presentation)
Frolich, Human Anatomy, Skin