bone part 1

yellow bone marrow

adipocytes and store triglycerides

when muscles contract they pull the bones which generates movement around a joint

longer than wide, bones of the limbs

as long as wide, wrist and ankle bones

thin and broad, skull and pelvis bones

irregular shape, vertebrae

small, flat, oval shaped bones located within tendons, the kneecap

outer dense irregular connective tissue membrane with blood vessels and nerves

collagen anchors that penetrate into bone matrix to attach the periosteum

shaft of the bone with a medullary cavity

lined by endosteum and filled with marrow

ends of long bone, filled with red marrow, covered with articular cartilage (made of hyaline cartilage)

hard dense outer bone that resists linear compression and twisting forces

inner framework that resists forces in many directions, place for bone marrow to reside

whats left of an epiphyseal plate, a line of hyaline cartilage actively growing in children

share similarities with long bones but have fewer structures

diploe

in some flat and irregular bones of the skull to make the bones lighter

provided by vessels in periosteum that penetrate bone

from periosteum and 1 or 2 nutrient arteries

enter through a small hole in the diaphysis called the nutrient foramen to supply the internal structures of the long bone

network of reticular fibers supporting islands of hematopoietic cells, infants have mostly red bone marrow becuase of rapid growth rate

65% of bones total weight, calcium salts and phosphorus as part of hydroxyapatite crystals

give bone its strength and ability to resist compression

bicarbonate potassium, magnesium, sodium salts

35% of bones total weight, protein fibers (collagen), bone specific proteins (osteocalcin)

helps bone resist torsion and tensile forces, aligns with hydroxyapatite crystals to enhance bone hardness

twisting

pulling or stretching

binds to calcium ions and hydroxyapatite crystals to organize bones inorganic matrix

draw water out of the blood vessels and cells to help the ECM resist compression

bind to both hydroxyapatite crystals and bone cells to bind them together

new bone is continually being formed as older bone is broken down

build bone and matures into osteocytes

maintain bone

break down bone

osteogenic cells

cubodial to columnar cells in the inner periosteum and endosteum

perform the process of bone deposition by secreting organic matrix and assiting in formation of inorganic matrix

osteoblasts surround themselves with matrix and become trapped in a cavity called a lacuna

secrete chemicals to maintain the ECM, recruit osteoblasts to build areas of bone under tension

large, multinucleate cells with ruffled border, derived from fusion of cells formed in the bone marrow

internal or external surfaces of bone

bone resorption ( breaking down bone ECM)

osteoclasts secrete hydrogen ions that dissolve inorganic matrix , secrete enzymes that break down organic matrix

minerals, amino acids, sugars

osteons or haversion systems

organized into branching "ribs" of bone called trabeculae

rings of very thin layers of bone, 4 to 20 in osteons, collagen fibers of adjacent lamellae run in opposite directions

resist twisting and bending forces

contains blood vessels and nerves, lined by endosteum

small cavities between lamellae filled with ECF, 20,000-30,000 found in each cubic millimeter of bone

tiny canals that connect lacunae, filled with think cytoplasmic extensions of osteocytes that contact each other through gap junctions

interstitial lamellae internally and circumferential lamellae in the inner and outer rings that strengthen bone

connect central canals of neighboring osteons and carry blood vessels from the periosteum to the central canals

covered with endosteum, contain concentric lamellae with lacunae and canaliculi housing osetocytes

from blood vessels in bone marrow