Skeletal System

SKELETAL SYSTEM

DEFINITION:

The framework of bones and cartilages that protects the organs and allows movement is called the Skeletal System.

TYPES OF BONES:

1.       Long Bones-Long Bones have greater length than width and consist of a shaft and a variable number of extremities (ends). Long Bones include those in the thigh (Femur), leg (Tibia and Fibula), toes (Phalanges), arm (Humerus), forearm (Radius and Ulna) and the fingers (Phalanges).

2.       Short Bones-Short Bones are somewhat cube shaped and nearly equal in length and width. E.g. - Carpal and Tarsal bones.

3.       Flat Bones-Flat Bones are generally thin and composed of two nearly parallel plates of compact bone enclosing a layer of spongy bone. Flat Bones afford considerable protection and provide extensive areas of muscle attachment. E.g. - Cranial Bones, Sternum and ribs, and Scapula.

4.       Irregular Bones-Irregular Bones have complex shapes and cannot be grouped into any of the three categories just described. E.g. - Vertebrae.

5.       Sutural Bones-Sutural Bones are small bones located within the joints (Sutures) of certain Cranial Bones.

6.       Sesamoid Bones-Sesamoid Bones are small bones that are embedded in tendons. E.g.- Patellae (Knee Cap).

DIVISIONS OF SKELETAL SYSTEM:

*        Total No. - 206

*        Acc. to Sushruta – 300

*        Acc. to Charaka – 360

Grouped in Two Principal Divisions-

1.       The Axial Skeleton.

2.       The Appendicular Skeleton.

THE AXIAL SKELETON:

·         The Longitudinal Axis or center of the human body is a straight line that runs through the body’s center of gravity.

·         This imaginary line extends through the head and down to the space between the feet.

THE APPENDICULAR SKELETON:

The Appendicular Skeleton contains the bones of the upper and lower limbs, plus the bones called Girdles whose function is to connect the limbs to the axial skeleton.

AXIAL SKELETON

1.       Skull- i) Cranium – 8,  ii) Face – 14

2.       Hyoid – 1

3.       Auditory Ossicles – 6

4.       Vertebral Column – 26

5.       Thorax- i) Sternum – 1  ii) Ribs – 24

SUBTOTAL= 80

                                                                             APPENDICULAR SKELETON

1.       Pectoral (Shoulder Girdles)-

                                 i.            Clavicle – 2

                               ii.            Scapula – 2

2.       Upper Limbs-

                                 i.            Humerus – 2

                               ii.            Radius – 2

                              iii.            Ulna – 2

                             iv.            Carpals – 16

                               v.            Metacarpals – 10

                             vi.            Phalanges – 28

3.       Pelvic (Hip) Girdle-

Hip, Pelvic, or Coxal Bone – 2

4.       Lower limbs-

                                 i.            Femur – 2

                               ii.            Fibula – 2

                              iii.            Tibia – 2

                             iv.            Patella – 2

                               v.            Tarsals – 14

                             vi.            Metatarsals – 10

                            vii.            Phalanges – 28

SUBTOTAL= 126

अस्थीप्रकार:एतानिपंचविधानिभवन्ति; तद्यथा–कपाल रुचक तरुणवलयनलकसंज्ञानि।-सुशा५/२२

·         कपाल– Flat Bones , eg – Skull Bones, Scapula, Hip Bone.

·         रुचक– Teeth.

·         तरुण–Cartilages, eg – Nasal Cartilage, Ear Auricle.

·         वलय– Vertebrae and Ribs.

·         नलक– Long Bones, eg – Humerus, Radius, Ulna etc.