3. Integumentary & Skeletal Systems Flashcards
Describe the 3 main layers of the skin:
Epidermis
Dermis
Hypodermis (subcutaneous)
Describe the 5 strata of the epidermis:
Corneum Lucidum Granulosum Spinosum Basale
The epidermis is made of ______ tissue and is avascular
epithelial
Describe the stratum corneum:
dead, flat cells filled with keratin
Describe the stratum granulosum:
cells flattening, organelles deteriorating, cytoplasm filled with ‘granules’
Describe the stratum basale:
deepest layer of epidermis, stem cells constantly dividing, some newly formed cells pushed upwards to superficial layers. Cells nourished by blood vessels in dermis.
Melanin is made by _________ in the epidermis
melanocytes
Describe the role of epidermal dendritic cells:
alert and activate immune system cells to bacterial/viral invasion
Merkel cells serve as _______
touch receptors
Name the 2 layers of the dermis:
papilliary (forms fingerprints)
reticular
Name the appendages of the skin:
sweat glands sebaceous glands arrector pili muscle hair follicles hair roots
The homeostatic functions of the skin are:
Sensation Thermoregulation Absorption Protection/Immunity Excretion Synthesizes vitamin D
Functions of the skeleton:
Protection of organs Support framework Allow movement Storage of minerals (bone) & fat (marrow) Blood cell formation (marrow cavity)
4 types of bones:
long ie. humerus
flat - ie. sternum
irregular - ie. vertebrae
short - ie. talus
Diaphysis:
shaft of a long bone
Epiphysis:
end of a long bone (proximal or distal)
Periosteum:
connective tissue membrane covering the diaphysis
Articular cartilage:
covers the external surface of epiphysis
hyaline cartilage
smooth surface that decreases friction at joint
Epiphysial line:
seen in adult bones, marks the remnant of the epiphysial plate where bone growth takes place in childhood
Epiphysial plate:
flat plate of hyaline cartilage
enables lengthwise growth of a long bone in childhood
Medullary cavity:
inner cavity of bone shaft