Chapter 7 Flashcards
functions of skeletal system
support and protect, levers for movement, hemopoiesis, storage of minerals and energy reserve.
Compact bone
dense; cortical bone. 80 percent of bone mass
spongy bone
cancellous, internal to compact bone. appears porous and is 20% of bone mass
long bones
greater in length than width
short bones
nearly equal from length to width
flat bones
flat, thin surfaces that may be slightly curved
irregular bones
elaborate, complex shapes
medullary cavity
contains red bone marrow in kids and yellow in adults. Inside of endosteum.
articular cartilage
at the end of long bones, reduces friction and absorbs shock in moveable joints
epiphyseal plate
growth plate, in adults the epiphyseal line remains after plate. in metaphysis.
periosteum
outer fibrous layer of dense irregular connective tissue that protects bone, anchors blood vessels and nerves and attachment site for ligaments and tendons. The inner cellular layer includes osteoprogenitor, osteoblasts, and osteoclasts
endosteum
contains osteoprogenitor cells, osteoblasts, and osteoclasts
nutrient foramen
small opening in bone where artery and nerves enter and vein exits.
bone marrow
2 kinds; red and yellow. is a soft connective tissue
red bone marrow
hemopoietic, located in spongy and medullary cavity in long bones in kids and located in skull, spine, ribs, sternum, and proximal epiphyses of humerus and femur in adults.
yellow bone marrow
product of red bone marrow degeneration as children mature-made out of fat/ may convert back to red in severe anemia
osteoprogenitor cells
stem cells that divide and create osteoblasts
osteoblasts
synthesize and secrete osteoid. becomes entrapped within the matrix and differentiate into osteocytes.
osteocytes
mature bone cells derived from osteoblasts. detect stress on bone and trigger new bone formation
osteoclasts
large, multinuclear, phagocytic cells involved in bone resorption
osteoid
osteoid is an organic compound produced by osteoblasts and contains collagen protein and semisolid ground substance of proteoglycans and glycoproteins. gives bones strength by resisting stretching and contributes to bone flexibility.
inorganic components of bone
salt crystals, calcium phosphate. Calcium phosphate interacts with calcium hydroxide to form crystals called hydroxyapatite. substances included in crystals are calcium carbonate, sodium, magnesium, sulfate, and fluoride. These crystals deposit around collagen fibers and make hard matrix.
bone formation
begins with secretion of osteoid and calcification occurs which is the deposition of hydroxyapatite crystals. bone formation requires vitamin d, c, calcium, and phosphate
Vitamin D is needed for what in bone formation
enhances calcium absorption from digestive tract