Bony framework that supports and protects organs and allows movement of the body.
membrane on outside of bone
4 types of CT
Functions of Bone
Movement, Protection, Support, Mineral Storage, Hemopoeisis, Energy Storage
Bone provides leverage for muscle contraction
Bone protects internal organs from physical injury.
Bone supports soft tissue and provides a point of attachment for skeletal muscles
Blood cell production occurs in RED bone marrow
YELLOW bone marrow contain lipids, an important source of energy.
80 bones that arranged along the longitudinal axis of the body.
126 bones appendages
Classification of bones
Long bones, short bones, flat bones, irregular bones, suture bones, sesamoid bones.
Longer than they are wide(femur)
ribs, sternum, scapula, cranium
found in cranium(coronal suture)
small bones embedded in tendon (patella)
proximal end of a long bone, which is spongy(cancellous) bone arranged in laticework of thin plates
Laticework of thin plates in end of long bone
shaft of long bone, which is compact bonce tissue made of concentric rings of hard bone
distal end of a long bone, with the same structure as the proximal epiphysis
(neck) area where the diaphysis joins the epiphysis
in growing long bones, a layer of hyaline cartilage that allows the diaphysis to grow in length.
where yellow bone marrow is found
found where two bones come together(joint). Thin layer of hyaline cartilage that coves the epiphyses. Function is to reduce friction at joint and absorb shock.
thin layer of dense CT membrane around the surface of a bone.
Function of periosteum
repair and nutrition of bone. Also tendons and ligaments attach to it.
membrane that lines the medullary cavity of the bone. It contains osteoprogenitor cells and osteoclasts.
Four types of cells in bone
Osteoprogenitor, Osteoblasts, osteocyte, osteoclast
Found in inner portion of the periosteum, in the endosteum and canals in bone that contain blood vessels. Function: to undergo mitosis and become osteoblasts.
cells that form bone tissue. They secrete collagen and matrix which calcifies to build bone tissue.
Mature bone cells, the main cells of bone tissue. They maintain bone tissue by exchanging nutrients and wastes with the blood.
bone cells and collagen fibers
calcium, phosphorus, and chemical components of the matrix
continuous ongoing replacement of old bone tissue with new bone tissue
osteoblasts are constantly forming new bone tissue, and osteoclasts are constantly destroying old bone tissue
calcium ion level in the blood is strictly regulated, regulated by parathyroid glands and thyroid gland
secrete PTH, increased PTH equals increased blood calcium level
secretes the hormone calcitonin, increased calcitonin equals decreased blood calcium level
Repair of bone
1. Fracture Hematoma
2. Fibrocartilaginous callus
3. Bony callus
formation of a blood clot under skin
organization of the fracture hematoma into granulation tissue called a procallus
Fibrocartilagious(soft) callus becomes bony(hard) callus.
restoration of the bone to near original structure and form
Compact (dense) bone
Consists of osteons with very little space between them
Composes bone tissue of the diaphysis
Function is to protect and support
dark spot in the middle of compact bone
1. Done NOT contain osteons
2. Consist of trabeculae surrounding many red-marrow filled spaces.
3. Found in short, flat and irregular bones and in the epiphyses of long bones.
Function is to store RED marrow and provide some support
layer of hyaline cartilage in the metaphysis of growing bone
Structure of the epiphyseal plate
1. Zone of resting cartilage
2. Zone of proliferating cartliage
3. Zone of Hypertrophic cartilage
4. Zone of calcified cartilage
Zone of Resting cartilage
Anchors the epiphyseal plate to the bone of the epiphysis
Zone of Proliferating Cartilage
layer of chondrocytes stacked like coins in columns
Zone of Hypertrophic Cartilage
large chondrocytes, stacked in columns
Zone of Calcified cartilage
only a few cells thick. Calcified matrix, cements epiphyseal plate to the bone of the diaphysis.