Chapter 6 skeletal system

6 main functions of the skeletal system

support, protection, assistance in movement, mineral homeostasis, blood cell production, triglyceride storage

long bone parts: diaphysis

Shaft

Filled with yellow bonemarrow

Epiphysis

end of bone (proximal and distal)

Contains red bone marrow

Red bc. Producing red blood cells

Metaphysis (long bone)

where diaphysis and epiphysis meet

epiphyseal plate

Thin layer of hyaline cartridge, once done growing replaced by bone tissue called epiphyseal line

medullary cavity

Space within shaft where yellow bone marrow is stored, energy storage

Endosteum

thin lining of connective tissue in the medullary cavity (inside bone)

Periosteum

Tough dense irregular connective tissue covering the bone

Attachment site for ligaments and tissues

Perforating fibers

collagen fibers that penetrate into the bone matrix

Articulate cartilage

Thin layer of hyaline cartridge that covers the ends of bones where they form a joint

The tough membrane that lines medullary cavities

Endosteum

Space within the shaft of the bone that contains yellow bone marrow

medullary cavity

Tissue that stores triglycerides for energy

Yellow bone marrow

a layer oh hyaline cartilage in the area between the shaft and end of the bone

epiphyseal plate

tissue that is hemopoietic ( makes red blood cells)

red bone marrow

thin layer of hyaline cartlisde that covers the ends of bones where they form a joint

articular cartliage

epiphysis of long bone

distal and proximal ends of the bone

shatf of bone

diaphysis

are of bone between ends of bone and shaft

metaphysis

tough memebrane that surrounds the bone surface where cartilage is not present

periosteum

tough membrane that lines the medullary cavity

endosteum

its apperance represents that a bon has stopped growing in length

epiphyseal line

two main components of bone matrix

crystalized mineral salts

collagen fibers

crystalized mineral salts of bone tissue

account for 50 percent

provide bone its hardness

collagen fibers og bone tissue

25 percent of bone tissue

form framework, can handle pulling anf twistning but not compression

provide the bone itd flexability and tensile strength

4 major types of cells found in bone tissue

osteogenic cells

osteoblastd

osteocyte

osteoclasts

osteogenic cells

Very immature bone cells that

differentiated from mesenchyme

(stem cells).

Able to undergo mitosis.

Provide a constant supply of bone

cells needed for growth and repair.

OSTEOBLASTS

Specialized fibroblasts that secrete collagen fibers into the matrix of bone tissue.

Stimulate changes in the area that

cause Calcium and Phosphorus salts

to deposit on the collagen fibers. The

“builders” of bone tissue.

Osteocytes

mature osteoblasts

maintain the bone matric by the exchange of nutrients and waste

Osteoclasts

forned from white blood cells, bvery large cells

remove bone tissue that has been damages

break down bone to release Calcium to the blood

calcification

deposition of calcium salts

stimulated by osteoblasts

Resorption

the process of removing or digesting old bone tissue

osteoclasts

compact bone

dense, hard layers of bone tissue that lie underneath the periosteum

thick in thre shaft of the bones

provides protection and support

Osteons

Cylindrical structures that comprise compact bone

Compact Bone: Central Canal

contains artery, vein, lyphatic vessel and nerve

compact bone: perforating canals

Perpendicular to the central canal

Carry blood vessels and nerves into bone marrow

compact bone: Lamellae

rings of hard calcified matrix, resemble tree rings

compact bone: Lacunae

spaces between lamellae filled with extracellular fluid

contains osteocyte

compact bone: Canaliculi

Hairlike canals that connect lacunae to each other and the central canal, gap junctions allws neighboring vells to communicate with each other

intersitial lamellae

regions of bone matrix between osteons

spongy bone (cancellous bone)

Layer of bone tissue having many small spaces and found just inside the layer of compact bone.

trabeculae

hard collumns of osseus tissue, large spaces for red blood

spongy bone is found

in the center of short flat and irregular shaped bone as well as the epiphyisis of long bones and lining of medulliary cavity

open spaces contain

red bone marrow

bone tissue is highly vascualar

rich blood supply, and each major long bone has several major blood vessels.

4 blood vessels bones

periosteal

nutrient

metaphysela

epiphyseal

periosteal

these enter and leave the bone tissue along the entire length of the diaphysis through numerous perforating canals and supply the periosteum and cells in the outer compact bone tissue

Nutrient

these enter and leave the bone near the center of the diaphysis through a hole in the compact bone called the nutrient foramen then divide into multiple branches that Supply the spongy bone tissue lining the medullary cavity of the diaphysis

metaphyseal arteries

enter the metaphyses of a long bone and, together with the nutrient artery, supply the red bone marrow and bone tissue of the metaphyses

epiphyseal arteries

enter the epiphyses of a long bone and supply the red bone marrow and bone tissue of the epiphyses