Skeletal System and Bones Flashcards
functions of skeletal system
support, protection, movement, mineral homeostasis, blood cell production (red bone marrow), triglyceride storage (yellow bone marrow)
axial skeleton
bones of head, neck, trunk
appendicular skeleton
bones of limbs inc. pectoral and pelvic girdle
compact bone
forms outer shell of all bones
hollow pillars of bone matrix containing nerves and blood vessels
spongy bone
filled with red or yellow bone marrow + medullary cavity
long bones
longer than they are wide
bear alot of weight
e.g- femur, humerus
short bones
similar width and length
stability and support with little movement e.g- carpal bones of wrist
sesamoid bones e.g-patella
flat bones
thin, flattened
protect vital organs, provide surfaces for large muscle attachment e.g- sterum, skull
irregular bones
e.g- vertebrae
anatomy of long bone (sections)
diaphysis: forms long axis of the bone
epiphysis: proximal and distal ends
metaphysis: region between epiphysis and diaphysis
HAS EPIPHYSEAL GROWTH PLATE of hyaline cartilage in growing bone/ epiphyseal line is adults
anatomy of long bone (components)
articular cartilage: hyaline cartilage covering the joint surface
periosteum: outer fibrous covering, double layered membrane
medullary cavity: hollow space within diaphysis, contains yellow bone marrow and blood vessels
endosteum: lines the medullary cavity
periosteal arteries
supply periosteum and outer compact bone
nutrient artery
enters via nutrient foramen at centre of diaphysis
osteoblasts
bone-building cells
synthesise and secrete collagen fibres
build extracellular matrix of the bone
initiate calcification
osteoclasts
break down bone/ bone resporption
releases lysosomal enzymes + acids the
digest proteins and mineral components of the ECM
intramembranous ossification
directly from mesenchyme (embryonic connective tissue
endochondral ossification
from cartilage derived from mesenchyme
during fetal period bone replaces cartilage
longitudinal bone growth
- interstitial growth of cartilage on the epiphyseal side of the epiphyseal plate
- replacement of cartilage on the diaphyseal side with bone via endochondral ossification
factors affecting bone growth and remodeling
vitamins and minerals (calcium hardens bone extracellular matrix + vit D increases calcium absorption)
exercise (weight-bearing activities stimulate osteoblasts)
hormones
