definition | term |
functions of skeletal system | protection
storage
blood cell formation
fat storage
movement
support |
bones organized by... | shape |
longer than wide | long bone |
cube-shaped, as long as they are wide | short bone |
thin, broad bones | flat bone |
don't fit in other classes | irregular bone |
bones within tendons | sesamoid bone |
long bone example | bones in arms and legs |
short bone example | bones in wrist/ankle |
flat bone example | ribs, sternum |
irregular bone example | vertebrae, certain skull bones |
sesamoid bone example | patella |
develop when stress is put on tendons | sesamoid bones |
makes red and white blood cells + platelets | red bone marrow |
made mostly of triglycerides and adipocytes | yellow bone marrow |
65% minerals + hydroxyapatite crystals | inorganic matrix |
osteoid with collagen, proteglycans, GAGs, glycoproteins, + bone-specific proteins | organic matrix |
bone-building cells that perform bone deposition | osteoblasts |
osteoblasts surrounded by bone matrix in lacuna | osteocytes |
means break down bone | osteoclasts |
mean build bone | osteoblasts |
multinucleated cells break down bone for remodeling | osteoclasts |
dissolve components of inorganic matrix | hydrogen ions |
break down organic matrix | enzymes |
process of bone formation | ossification/osteogenesis |
occurs within membrane | intramembranous ossifictaion |
forms many flat bones | intramembranous ossification |
occurs inside hyaline cartilage | endochondral ossification |
forms long bones arms + legs | endochondral ossification |
long bones develop by... | - chondrocytes swell
-osteoblasts build bony collar for support
- chondracytes die from lack of nutrients
- bone builds to fill space |
chondrocytes divide in epihyseal plate | longitudinal growth |
can be recruited for bone growth | zone of reserve cartilage |
zone of dividing chondrocytes | zone of proliferation |
contains mature chondrocytes | zone of hypertrophy/maturation |
dead chondrocytes + some calcified | zone of calcification |
calcified chondrocytes + osteoblasts | zone of ossification |
zones epiphyseal plate: close-far | - zone of reserve cartilage
- zone of proliferation
- zone of hypertrophy/maturation
- zone of calcification |
bones grow in width | appositional growth |
new, round lamella are formed | appositional growth |
osteoblasts put calcium into bloodstream | bone deposition |
osteoclasts break down bone to reabsorb calcium | bone resorption |
physical factors why bone remodel | - tension/stress + compression increase tissue in bone |
hormonal factors why bone remodel | - testosterone/estrogen stimulate bone growth |
dietary factors why bone remodel | - calcium ion
- vitamin D
-vitamin C
- vitamin K
- Protein |
increase blood calcium ion levels | parathyroid hormone |
increase osteoclast activity to relase calcium | parathyroid hormone |
tells digestive system to absorb calcium in food | parathyroid |
inhibits calcium in urine | parathyroid |
Hormone decreasing calcium ion levels | calcitonin |
Hormone that leads to bone deposition | calcitonin |
Affects the absorption of calcium ions from the gut | Vitamin D |