skeletal system Flashcards
Consists of 80 bones, comprising the skull, vertebral column, and thoracic cage
Axial Skeleton
Consists of 126 bones, including all bones of the upper and lower limbs, plus the bones of the pectoral and pelvic girdles that attach each limb to the axial skeletal
Appendicular skeletal
How are bones of the skeletal system classified based on their shape?
Flat
Long
Sesamoid
Irregular
Short
Sutural
What are the four types of cells in bones and what are their functions?
Osteogenic cell - stem cell
Osteoblast - bone builders
Osteoclast - bone cleaver (resorption)
Osteocyte - maintains bone
What are some of the major differences and similarities between endochondral ossification and inter membranous ossification?
Endochondral ossification consists of chondrocytes forming matrix in hyaline cartilage where calcfication leads to cell death and produces osteogenic cells for the bone to develop.
Intermembranous Ossification consists of osteoblasts gathering in ossification center to secrete osteoid and calcium. Calcified matrix traps osteoblasts to form osteocytes and eventually leads to surface bone tissue to form compact bone
What are the 5 zones in long bone formation?
Reserve Zone
Proliferative Zone
Zone of maturation and hypertrophy
Zone of calcified matrix
Zone of ossification
what are the steps in bone appositional growth? (diameter growth)
Osteoclasts resorbs old bond that lines medullary cavity while osteoblasts produce new bone tissue beneath the periosteum. Both diameters of the diaphysis and medullary cavity increase.
What are the steps in bone remodeling after an injury?
Origination
Activation
Resorption
Formation
Mineralization
How do osteocytes regulate bone resorption and bone formation via RANKL-RANK interaction?
RANKL (osteocyte) - RANK (preosteoclast) interaction promotes osteoclastogenesis
How do osteocytes regulate bone resorption and bone formation via RANKL-OPG interactions ?
RANKL (osteocyte) - OPG (osteocyte) interaction promotes bone formation
How do osteocytes regulate bone resorption and bone formation via the SOST pathway?
SOST inhibit bone formation and activate bone resorption
progressive systemic skeletal disease characterized by low bone mass and micro-architectural deterioration of bone tissue, with consequent increase in bone fragility and susceptibility of fracture
Osteoporosis
What are the associated risk factors for osteoporosis?
early menopause (low estrogen)
eating disorders
small body frame
family history of osteoporosis
early malnutrition
low vitamin D
certain medications
intestinal pathology
space flight
What are the preventative measures for osteoporosis?
Weight bearing exercise
What are the functions of the skeletal system?
Support
Movement
Protection
Mineral Storage
Energy Storage
Hematopoiesis
What step in long bone formation consists of small chondrocytes within the matrix that do not participate in bone growth but secure the epiphyseal plate to the osseous tissue of the epiphysis?
Reserve Zone
What step in long bone formation consists of stacks of slightly larger chondrocytes and makes new chondrocytes (mitosis) to replace those that die at the diaphyseal end of the plate?
Proliferative Zone
What step in long bone formation consists of chondrocytes being older/larger and mature cells are situated closer to the diaphyseal end of the plate?
Zone of maturation and hypertrophy
What step in long bone formation contains chondrocytes that are dead because the matrix around them has calcified. Capillaries and osteoblasts from the diaphysis penetrate this zone. The osteoblasts secrete bone tissue on the remaining calcified cartilage. (zone closest to diaphysis)
Zone of calcified matrix
What step in long bone formation consists of the zone of calcified matrix connecting to the epiphyseal plate to the diaphysis and osseous tissue added to the diaphysis results in length growth?
Zone of ossification
