Skeletal system is a framework of bones and cartilages, this is
important for the movement of body.
Bones and cartilages are specialised connective tissue.
Bone is made up of very hard non pliable cells- osteons.
Osteons contains haversian canals surrounded by concentric
rings of osteocyte
It is rich in Ca2+ salts.
Cartilage- consists of solid pliable chondrocytes, which
contain chondroitin salts
In human body , there are 206 bones, which is divided mainly
into axial and appendicular skeleton.
Axial consists of 80 bones, which is distributed over skull,
vertebral column, sternum and ribs.
Bone in the skull is divided into, cranial(8) and facil (14).
So as to form a total of 22.
Hyoid , a single u shaped bone, is also a skull bone.
Ear ossicles are - malleus, stapes and incus, which is also
seen in the skull region.
Vertebral column has cervical (7) thoracic (12), lumbar (5),
sacral ( 1 -fused ) and coccygeal (1- fused) , forming a total of
26 serially arranged units.
Sternum, located in midline of thorax ,is a flat bone
There are 12 pairs of rib, which is connected dorsally to
vertebral column and ventrally to sternum. Of this 7 are true ribs
( as directly connected to sternum), 8,9 and 10 are false ribs (
through hyaline cartilage to sternum) and 11 and 12 are floating
ribs ( not connected to sternum)
Appendicular skeleton, forming the bones of limb, each limb
consists of 30 bones, ( forelimb- humerus, radius, ulna,
carpels(8), metacarpels (5)and phalanges (14), Hindlimb - femur,
tibia, fibula, tarsals (7), metatarsals (5), phalanges (14) ,
patella ]
Pectoral and pelvic girdle plays major role in movement of
upper and lower limb, these are divided into two halves.
Each half of pectoral girdle consists of scapula and clavicle,
which forms glenoid cavity for articuation.
Pelvic girdle consists of two coxal bones, they are the fusion
of illeum, ischium and pubis.
Joints are required for the movement of bony parts.
Joints are classified into:
1) Fibrous joint - no movement, formed by flat skull bones with
dense fibrous tissue., thus forming the cranium
2) Cartilaginous joints - joint formed with help of cartilage,
seen in vertebral column
3)Synovial joint - they contain fluid filled synovial cavity,
between articular surfaces of the bones.
a) ball and socket joint - between humerus and pectoral
girdle
2) hinge joint - knee joint
c) pivot joint - between atlas and axis
d)gliding joint - between carpels
e)saddle joint- between carpel and metacarpel of thumb