Skeleton is the internal framework of our body. It is composed of around 300 bones at
birth.These bones get fused and the adult Skeleton is made up of 206 bones
only.skeleton is divided into major parts
1.Axial Skeleton
2.Appendicular skeleton
1.AXIAL SKELETON:-It forms axis of the body.It consists of skull,rib cage,sternum and
vertebral column
a.SKULL:-It is divided into two parts
.cranium
.face
Cranium:-its formed of eight flat bones
1.one frontal
2.two temporal
3.two parietal
4.one occipital
5.one ethmoid
6.one sphenoid
Face:-face is formed of 14 fused bones
1.two zygomatic bones(cheek bones)
2.two palate bones
3.two nasal inferior conchae
4.two nasal bones
5.two maxillary
6.two lacrymal
7.one mandible
8.one vomer
b.VERTEBRAL COLUMN:-It consists of 33 movable bones.
1.7 cervical
2.12 thoracic
3.5 lumber
4.5 sacral
5.4 coccygeal
c.STERNUM:-it is divided into 3 parts
. Manubrium sternum(upper part of sternum)
.body
. xiphoid process
Body gives attachment to 3rd 4th 5th 6th and 7th rib
Xiphoid process gives attachment to diaphragm linea alba and rectus abdominis muscle.
d.RIBS:-There are 12 pairs of ribs
.True ribs:-7 pairs
.false ribs:-3 pairs
. floating ribs:-2 pairs
2.APPENDICULAR SKELETON:-it consists of;
, Shoulder girdle
Pelvic girdle
Upper limbs
Lower limbs
SHOULDER GIRDLE:- also called pectoral girdle.It consists of scapula and clavicle
1.scapula:-It is also called the shoulder blade.
It has 3 borders,three angles,two processes and two surfaces.
A.Borders of scapula:-
.Superior border
.Medial or vertebral border
. Axillary border
B.Angles of scapula:-
. superior angle
.inferior angle
.lateral or external angle
C.Processes:-
.Acromion process
.coracoid process
D.Surfaces of scapula:-
.Anterior or costal surface:-It contains suprascapular fossa(nearest to the ribs)
. posterior or dorsal surface:-it is divided by means of supine into supraspinatus fossa
and infraspinatus fossa.
On the lateral side of the scapula is present a cavity called glenoid cavity,the head of the
humerus is fitted in the glenoid cavity to form a shoulder joint.
2.clavicle:-it contains;
.Shaft
.Two ends, acromion end and sternal end
.Four borders
PELVIC GIRDLE:-it is a skeletal ring made up of two innominate bones ,the sacrum and
the coccyx
INNOMINATE BONE:-it is also called pelvic bone or hip bone.It is made up of 3 bones
.Ilium
.ischium
.pubis
ILIUM:-It is the upper flattened out portion of the innominate bone.The border of Ilium is
called iliac crest,crest of Ilium contains four iliac spines;
. Anterior superior iliac supine; bony prominence towards anterior side of iliac crest
. Posterior superior iliac spine;bony prominence towards posterior side of iliac crest
. Anterior inferior iliac spine;bony prominence below anterior superior iliac spine
. posterior inferior iliac spine;bony prominence below posterior superior iliac spine.
Internal surface of Ilium is concave called iliac fossa which gives attachment to iliac
muscles.
. ISCHIUM:-It is the lower thick part of the innominate bone.it contains;
ischial tuberosity,takes the weight of sitting body