Structure of long bone

Bone contains neatly arranged matrix of protein (collagen) fibers along with water and mineral salts (calcium hydroxide & calcium

phosphate).The mineral salts accumulate in-between and around the collagen

fibers, they crystallize and the tissue hardens

Human skeletonThe adult human skeleton is made up out of 206 bones. Within the body you can distinguish between the axial and appendicular skeleton. The axial skeleton is mainly for protection of organs, blood cell production and support / attachment area for muscles. The appendicular skeleton’s main function is movement. Other functions are the storage of minerals and storage of energy (fat)The axial skeleton consists of: the skull (cranium) ribs, sternum, vertebral column consisting of cervical (7), thoracic (12), lumbar (5), sacral (5-fused) and coccyx (4-fused)The appendicular skeleton: pectoral girdle (scapulae and clavicles), humerus, radius, ulna, carpals, metacarpals, phalanges, pelvic girdle (ilium, ischium and pubis), femur, patella, tibia, fibula, tarsals, metatarsals and phalanges

Four types of boneThe bones in the human body vary widely in size and shape. Within the skeleton the bones can be classified into four types- Long bones; cylindrical

shaft and enlarged at both ends (femur, metatarsals)

- Short bones; small cube-shaped (carpals, tarsals)

- Flat bones; curved broad surfaces (sternum, ribs)

- Irregular bones; specialized shapes

• "LONG BONE" = typical bone• Major parts:

1. EPIPHYSIS - expanded ends of bone made of spongy or cancellous bone. Cancellous bone has a honeycomb structure with many spaces. Red bone marrow is stored in cancellous bone, blood cell production occurs here. ARTICULATES (forms a joint) with another bone.2. DIAPHYSIS - shaft of the bone made of compact or hard bone important for protection and support 3. ARTICULAR CARTILAGE - hyaline cartilage covering the ends of bones, function is to reduce friction between bones and absorb shock 4. PERIOSTEUM – tough shiny white membrane covering over entire bone, except for articular cartilage. Connect with tendons and ligaments. Forms bone tissue and is important for growth, ntrition and repair.

• MEDULLARY CAVITY - hollow chamber within the diaphysis connects to spaces in spongy (cancellous) bone. Filled with soft specialized tissue called yellow bone marrow.

• NUTRIENT FORAMEN – Small opening in the diaphysis, blood vessels pass through here, enter the medullar cavity and provide the bone marrow and compact bone with blood and nutrients

• " Red Marrow - mainly in spongy bone in adults. Produces blood cells" Yellow Marrow - fat storage in adipose cells, energy reserve

• ENDOSTEUM - lining of the medullary cavity

• Femur can take approx. 1000kgs of pressure• Skeleton takes up 14% of the total body weight• Born with 300 bones, you end up with 206• Red bone marrow can produce around 5 billion red blood cells each day.• 80 bones are found in the axial skeleton, which consists of the bones in the skull, face, and torso.

There are 28 bones in the skull (including facial bones and middle-ear bones). • The appendicular skeleton consists of 126 bones and includes the arms, hands, legs, feet, shoulder

girdle, and the pelvic girdle.• Each of our hands consists of 27 bones

http://www.youtube.com/watch?v=mgNLchwqJ8Q&feature=related