Chapter 6: Bone Tissue

Medullary Cavity

large cavity within the diaphysis

Red Marrow

connective tissue in the spaces of spongy bone or in the medullary cavity; the site of blood cell production

Spongy Bone

consist of interconnecting rods or plates or bone called "trabeculae"; between the trabeculae are spaces, which in life are filled with bone marrow and blood vessels

Osteoblasts function

Produce collagen and proteoglycans Secrete matrix vesicles

Articular Cartilage

a type of hyaline cartilage that covers the end of a long bone

perichondrium

double-layered outer layer of dense irregular connective tissue surrounding cartilage; contains fibroblasts

proteoglycans function

make cartilage resilient by trapping water

Osteocytes

mature bone cells surrounded by bone matrix; housed within the lacunae

Perforating Canals

"Volkmann Canals" deliver blood to the central canals of the osteons; Run perpendicular to the length of the bone; contain blood vessels from the periosteum or medullary cavity

Ossification

"osteogenesis"; bone formation; occurs by appositional growth on the surface of previously existing material (bone or cartilage)

Articular cartilage

Hyaline cartilage that covers the ends of bones where they come together to form joints; has no perichondrium, blood vessels, or nerves

Osteoblasts

bone-building cells; have an extensive ER and numerous ribosomes

Osteoclasts

bone-destroying cells; break down bone

chondroblast

cartilage-producing cell

Perforating Canals

deliver blood to the central canals of the osteons; contain blood vessels from the periosteum or medullary cavity

Yellow Marrow

fat stored within medullary cavity or in the spaces of spongy bone

Circumferential Lamellae

form the outer surface of compact bone, which are thin plates that extend around the bone

Bone Collar

formed by when osteoblasts produce compact bone on the surface of the cartilage

Epiphyseal Plate

hyaline cartilage between the diaphysis and epiphysis; its growth allows for growth in bone length

Lamellar Bone

mature bone; organized into thin, concentric sheets or layers approximately 3-7 micrometers thick called "lamellae"

chondrocyte

mature cartilage cell; rounded cells that occupy a lacuna

Canaliculi

narrow, long spaces where osteocyte cell extensions are housed

Periosteum

out, double-layered connective tissue membrane with ligaments and tendons attached to bone through the periosteum; blood vessels and nerve pathways; the periosteum is where bone grows in diameter

Interstitial Lamellae

remnants of concentric or circumferential lamellae that were partially removed during bone remodeling

Diaphysis

shaft of long bone; the center portion of the bone; composed primarily of compact bone, surrounding a hollow center cavity

lacuna

small space or cavity; potential space within the matrix of bone or cartilage normally occupied by a cell that can be visualized only when the cell shrinks away from the matrix during fixation

Fontanels

soft spots; the larger, membrane-covered spaces between the developing skull bones that have not yet been ossified

Endochondral Ossification

starts with a cartilage model; beings at app. the end of the 4th week of the embryonic development. Bones at the base of the skull, part of the mandible, the epiphyses of the clavicles, and most of the remaining skeletal system develop from this form of ossification

Intramembranous ossification

starts within embryonic connective tissue membranes; starts at app. 2 years of age. Skull bones, part of the mandible, and the diaphysis develop from this for of ossification

Collagen provides:

strength

Central Canal

the "bull's eye" of the target (osteon)

Bone Reabsorption

the breakdown of bone; important for mobilizing crucial Ca+2 and phosphate ions for use in many metabolic processes.

Epiphysis

the ends of a long bone; mostly spongy bone, with an outer layer of compact bone; develops from its own center of ossification

Woven Bone

the first type of bone that osteoblasts form during ossification; fairly weak bone because the collagen fibers are randomly oriented in many directions

interstitial growth

the growth where chondrocytes in the center of the tissue divide and add more matrix in between the existing cells

hyaline cartilage

the most important cartilage since most bones in the body start out as a hyaline cartilage model.

Concentric Lamellae

the rings of bone matrix surrounding the central canal

Compact Bone

the solid, outer layer surround each bone; has more matrix and is denser with fewer pore than spongy bone; appears solid

Endosteum

thin connective tissue membrane lining the inner cavities of bone

Appositional growth

type of growth where chondroblasts in the perichondrium add new cartilage to the outside edge of the existing cartilage