Intro to skin and integuement Flashcards
What is Integument?
The enveloping membrane of the body including all derivatives of the epidermis
What is the approximate surface area of the skin (adult)?
1.5-2m2
What are the three key layers of skin? (outer layer first)
Epidermis
Dermis
Subcutis- subcutaneous layer
Which layer of the skin is avascular?
Epidermis
What are the layers of the epidermis from top to bottom (included in thick skin)
Stratum lucidum — (thick skin only
Stratum corneum Stratum granulosum Stratum spinosum Stratum basale Basement membrane
What cells does the Stratum basale contain?
columnar keratinocytes
What cells does the Stratum spinosum contain?
polyhedral keratinocytes
What cells does the Stratum granulosum contain?
3-5 layers flattened keratinocytes
What cells does the Stratum corneum contain?
corneocytes 20-30 cells thick
What cells does the Stratum lucidum contain?
dead keratinocytes
What is the Stratum basale for?
adherence
What is the Stratum spinosum for?
adherence/strength
What is the Stratum granulosum for?
waterproofing
What is the Stratum corneum for?
shedding layer
What is the scalp?
thin skin and subcutaneous tissue
What are the borders of the scalp?
superior border occipital bone to supra-orbital margin of frontal bone
laterally extending over temporal fascia to zygomatic arches
What are the layers of the scalp?
Skin Connective tissue(dense) Aponeurotic layer Loose connective tissue Pericranium
Why is is not too worrying if the scalp looks down to the bone
They may have reached to aponeurosis layer
What to do if there is a scalp injury? Why?
Apply direct pressure
Bleeding can expand the loose connective tissue layers and cause swelling
What causes swelling in the scalp?
Injury causes bleeding
Blood not pressurised expands the loose connective tissue layers under the aponeurosis.
Why does the scalp bleed easily?
Good vascular supply
What causes wrinkles?
Loss of elasticity of dermis
How does the skin vary in adherence? What?
Lots of short fibrous bands more adherence less mobility
Long less fibrous bands less adherence more mobility
Where is toughest skin located
Soles of feet