Integumentary system Flashcards
divisions of the integumentary system
cutaneous membrane
- skin
accessory structures
- hair
- nails
- exocrine glands
5 general functions of skin
- protect underlying tissues + organs
- excretes salt, water + organic wastes
- maintains body temp
- synthesises vitamin D3
- stores lipids
- detects touch, pressure, pain + temp
describe the epidermis
outer, thinner layer
composed of epithelium
describe the dermis
inner, thicker layer
composed of connective tissue
contains nerves
describe the structureof the hypodermis
fat store
contains blood vessels
has pacinian corpuscles (sensitive to pressure)
list the 5 layers of the epidermis in order from outermost
- stratum corneum
- stratum lucidum
3.stratum granulosum - strata spinosum
- stratum basale/germinativum
structure of stratum corneum
- multiple layers of dead, flat keratinocytes
- water resistant, X waterproof
- fluid loss via insensible perspiration
structure of stratum lucidum
dead keratinocytes
present in thick skin subject to increased friction
structure of stratum granulosum
- keratin fibres develop as cells become thinner + flatter
- lamellar granules secrete waterproofing chemical
structure of strata spinosum
desmosomes hold cells together
structure of stratum basale
attached to basement membrane
made of stem cells, melanocytes, dendritic cells + tactile cells
describe the formation of a callus
abnormal thickening of stratum corneum due to constant exposure of skin to friction
list the two layers of the dermis
papillary layer
reticular layer
structure + function of papillary layer
- areolar tissue
- contains small capillaries, lymphatics + sensory neurons
- contains tactile corpuscles
structure + function of reticular layer
- dense, irregular connective tissue
- collagen + elastic fibres provide strength + flexibility
- contains larger blood vessels, lymph vessels + nerve fibres
what can be used to assess skin dehydration in the clinic
skin turgor - elasticity of skin + its ability to change shape + return back to normal