CLASSIFICATION OF BONES:
Classification of Bones with examples also explain types of bones like Long Bones, Short Bones, Irregular Bones, Flat Bones and included all types of bones in human body and bones in human body.
CLASSIFICATION OF BONES:
Bones are classified according to their shapes
LONG BONES:
are tubular (e.g., the humerus in the arm).
SHORT BONES:
are cuboidal and are found only in the tarsus (ankle) and carpus (wrist).
FLAT BONES:
usually serve protective function (e.g., the flat bones of the cranium protect the brain).
IRREGULAR BONES:
have various shapes other than long, short, or flat (e.g., bones of the face).
SESAMOID BONES:
(e.g., the patella or knee cap) develop in
certain tendons and are found where tendons cross the ends of long bones in the limbs; they protest the tendons from excessive wear and often change the angle of the tendons as they pass to their attachment.
CREST:
ridge of bones (e.g., the iliac crest).
EPICONDYLE:
eminence superior or adjacent to the condyle (e.g., lateral epicondyle of the humerus) .
FACET:
smooth flat area, usually covered with cartilage, where a bone articulates with another bone (e.g., superior costal facet on the body of the vertebra for articulation with a rib).
FORAMEN:
passing through a bone a (e.g., obturators foremen).
FOSSA:
hollow to depressed area (e.g,. infraspinatus fossa of the scapula).
GROOVE:
elongated depression and furrow (e.g., radial groove to the humerus).
HEAD:
(L.caput): large around articular end (e.g., head of the humerua).
LINE:
linear evolution, sometime called a ridge (e.g., soleal line of the tibia).
MALLEOLUS:
rounded process(e.g., lateral malleolus of the fibula).
NECK:
relatively narrow portion proximal to the head.
NOTCH:
indentation at the edge of he bone (e.g., greater sciatic notch0.
PROCESS:
an extension or protection serving a particular purpose, shapes having a characteristics shapes, or extending in a particular direction (e.g., articular process, spinous process or transverse process of a vertebra.
SHAFT:
the diaphysis, or body, of a long bone.
SPINE:
thorn-like process (e.g., the spine of the scapula).
TROCHANTER:
large blunt elevation (e.g., greater trochanter of the femur).
TROCHELA:
spool-like articular process or process that act as a pulley (e.g., trochlea of the humerus).
TUBERCLE:
small raised eminence (e.g., greater tubercle of the humerus).
TUBEROSITY:
large rounded elevation (e.g., ischial tuberosity).
BONE DEVELOPMENT:
Most bones take many years to grow and mature. For example, the humerus (arm bone) begins to ossify at the end of the embryonic period (8 weeks); however, ossification does not complete until the age of 20. All bones are derived from mesenchyme (fetal connective tissue) through two different processes: intramembranous ossification (directly from mesenchyme) and cartilage internalization (from mesenchymal-derived cartilage). The histology (microstructure) of the bone is the same in either of the two processes (Pawlina, 2016). The two processes of bone development are as follows:
1: in intramembranous ossification:
(membranous bone formation), the bones mesenchymal pattern is formed in the embryonic period, and the mesenchymal targeting starts in the fetal period.
2: In endochondral ossification:
(chondral bone formation), the cartilage pattern of the bone is formed by mesenchyme during the fetal period, and subsequently, bone replaces most of the cartilage.
A brief description of endochondral ossification helps explain the extent of bones. Mesenchymal cells condense and differentiate into chondrocytes, divide cells in the growing cartilage tissue, thereby forming a cartilage bone model.
In the middle area of the model, cartilage is calcified (impregnated with calcium salt), and periosteal capillaries (capillaries in the fibrous sheath around the model) grow into the calcified cartilage of the bone model and supply its interior.
These blood vessels and related osteogenic (osteoblasts) cells form periosteal buds The capillaries initiate the primary ossification center, so named because the bone tissue it forms replaces most of the cartilage in the main body of the bone model. The axis of ossified bone starting from the primary ossification center is the backbone, which grows as the bone develops.
Development and growth of long bones. A. Shows the formation of primary and secondary ossification centers. B. The length increase occurs on both sides of the cartilaginous epiphyseal plate (double arrow). The bone formed from the main center on the diaphysis will not fuse with the bone formed from the secondary center on the epiphysis until the bone reaches adult size. When growth stops, the depleted epiphyseal plate is replaced by interosseous fusion (bone-to-bone fusion), which is seen as the epiphyseal line on X-rays and bone slices.
Most secondary ossification centers appear in other parts of the bone that is developing after birth; the part of the bone that ossifies from these centers is the epiphysis. The cartilage cells in the middle of the epiphyseal hypertrophy and the bone matrix (extracellular material) between them are calcified. The epiphyseal artery grows in the developing cavity and is accompanied by associated osteoblasts.
The widened part of the axis closest to the epiphysis is the metaphysis. In order to continue growth, the bone formed from the main center in the diaphysis will not fuse with the bone formed in the secondary center in the epiphysis until the bone reaches adult size. Therefore, during the growth of long bones, the cartilaginous epiphyseal plate intervenes between the diaphysis and epiphysis. These growth plates are eventually replaced by bones on both sides, diaphysis and epiphysis.
When this happens, bone growth stops and the backbone fuses with the epiphysis. The seams (sutures) formed during this fusion process are particularly dense and are recognized as epiphyseal lines in sliced bone or X-rays .
From adolescence to maturity, fusion of the epiphyses gradually occurs. The ossification of short bones is similar to the primary ossification center of long bones, only one short bone calcaneus (calcaneus) develops into a secondary ossification center.
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Bones