Anatomy and Physiology (Tortora) Chapter 6
Osteogenic cells
.undergo cell division and develop into osteoblasts
Calcium
99% stored in bone
Calcitriol
Active form of vitamin D. Stimulated by the parathyroid hormone
Yellow bone marrow
Adipose tissue. Stores fat. Found in the medullary cavity. Contain small blood vessels that provide nutrients to osteocytes
Mesenchyme
An embryonic connective tissue that develops into connective and skeletal tissues, including blood and lymph. Irregularly shaped cells embedded in semifluid ground substance
Fracture
Any break in the bone
Circumferential lamellae
Arranged around the entire inner and outer circumference of the shaft of a long bone. They develop during initial bone formation
Hemopoiesis
Blood cell production, which occurs in red bone marrow after birth
Osteoblasts
Bone building cells, synthesize and secrete collagen fibers and other components needed for bone formation, initiate calcification. Become trapped in their secretions and become osteocytes
Osseus tissue
Bone tissue
Resorption
Breakdown of bone extracellular matrix
Haversian canal
Central canal of an osteon (also called osteonic cannal)
Concentric lamellae
Circular plates of mineralized extracelluar matrix, increasing in diameter, and surrounding a small network of blood vessels and nerves
Calcification
Deposition of mineral salts, primarily hydroxyapatite, in a framework formed by collagen fibers in which the tissue hardens. Also called mineralization
Epiphysis
End of a long bone, usually larger in diameter than the shaft
Ossification
Formation of bone. Also called osteogenesis
Neighboring osteocytes communicate via this
Gap junctions
Extracellular matrix
Ground substance and fibers between cells of the connective tissue
Appositional growth
Growth due to surface deposition of material, as in growth in diameter of cartilage and bone
Interstitial growth
Growth from within, as in the growth of cartilage
Fibrocartilaginous callus
Happens in the reparative phase. A mass of repair tissue consisting of collagen fibers and cartilage that bridges the broken ends of the bone
Bony callus
Happens in the reparative phase. Fibrocartilage is converted to spongy bone and it gets a spiffy new name (cause we need another name to learn)
Red bone marrow
Highly vascularized connective tissue located in microscopic spaces between trabeculae of spongy bone tissue. Have small blood vessels that provide nutrients to osteocytes
Osteoclasts
Huge cells concentrated in the endosteum. Break down of bone extracellular matrix (called resorption). Have ruffled border. Help regulate blood calcium level
Articular cartilage
Hyaline cartilage attached to articular bone surfaces
Epiphyseal plate
Hyaline cartilage in the metaphysis of a long bone. Site of LENGTHWISE growth of long bones. Also known as the growth plate
Secondary ossification center
In the epiphysis in long bones. Appears after primary ossification center. Spongy bone remains in the interior, exterior is similar to primary ossification center.
Volkmann's canal
Interosteonic canal. Perforating canal. Go transverse through the osteon. Vessels and nerves go through them from the periosteum to the central canal. Also connects with blood vessels and nerves of the medullary cavity
Bone formation
Intramembranous ossification, endochondral ossification
Trabeculae
Irregular latticework of thin plates of spongy bone tissue.
Zone of hypertrophic cartilage
Large, maturing chondrocytes arranged in columns
Zone of resting cartilage
Layer nearest the epiphysis. Consists of small, scattered chondrocytes. Cells anchor epiphyseal plate to the epiphysis of bone
Lacunae
Located between the concentric lamallea. Hold one or two osteocytes
Cortical/ compact bone
Made of osteons
Collagen
Main structural protein found in skin. Big in bones, too- lose it and bones become brittle and lose their flexibility.
Fracture hematoma
Mass of blood (usually clotted) that forms around the site of a bone fracture
Periosteum
Membrane that covers bone and consists of connective tissue, osteogenic cells, and osteoblasts. Essential for bone growth, repair, and nutrition
Phosphorus
Needed for bone growth. Works with Ca to form bone
Bone remodeling
Ongoing replacement of old bone tissue by new bone tissue
Zone of calcified cartilage
Only a few cells thick. Mosly has dead chondrocytes. Calcified extracellular matrix. Becomes the "new diaphysis" that is firmly cemented to the rest of the diaphysis of the bone
Parafollicular cell
Produces calcitonin, which helps regulate the levels of calcium and phosphate in the blood by inhibiting bone resorption and by accelerating the uptake of calcium and phosphates into the bone matrix
Metaphysis
Region of long bone between diaphysis and epiphysis that contains the epiphysisial plate in a growing bone
Primary ossification center
Region where bone tissue will replace most of the cartilage- first area of bone to start ossifiying
Epiphyseal line
Remnant of the epiphyseal plate in the metaphysis of the long bone
Bone resorption
Removal of minerals and collagen fibers from bone by osteoclasts
Osteons
Repeating structural unit of compact bone
Endochondral ossification
Replacement of cartilage by bone
Tensile strength
Resistance of material to breaking under tension by pulling (as opposed to compression)- think pulling taffy
Parathyroid hormone
Secreted by parathyroid gland. Increases blood calcium level and decreases blood phosphate level
Calcitonin
Secreted by the parafollicular cells of the thyroid gland. Inhibits activity of osteoclasts, speeds up blood calcium uptake by bone, accelerates blood calcium deposition of bones
Diaphysis
Shaft of a long bone. Contains compact bone, a very small amount of spongy bone, the medullary cavity, and yellow bone marrow. Also has the nutrient foramen and arteries and veins. Surrounded by periosteum. Has the endosteum (lining of the medullary cavity)
Zone of proliferating cartilage
Slightly larger chondrocytes stacked like coins. They undergo interstitial growth, divide, and secrete extracellular matrix. Chondrocytes divide to replace those that die at the diaphyseal side of the epiphyseal plate
Medullary or marrow cavity
Space within the diaphysis of a bone that contains yellow bone marrow.
Trabecular bone
Spongy bone, contains trabeculae
Interstitial lamellae
The area between osteons. They contain lacunae with osteocytes and canaliculi
Intramembranous ossification
The method of bone formation in which the bone is formed directly in mesenchyme arranged in sheetlike layers that resemble membranes
Endosteum
c.t that lines medullary cavity
bones thin
due to loss of the mineral calcium.
Canaliculi
tiny channels that connect lacuana allow osteocyte and recieve nutrients
bones brittle
to the loss of collagen