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 skeleton
The 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 (4fused)
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 bone
The 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
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"LONG BONE" = typical bone
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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
http://www.youtube.com/watch?v=mgNLchwqJ8Q&feature=related
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Femur can take approx. 1000kgs of pressure
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Skeleton takes up 14% of the total body weight
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Born with 300 bones, you end up with 206
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Red bone marrow can produce around 5 billion red blood cells each day.
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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