• Macroscopic Skeleton

• Bone Structure

• Microscopic Skeleton

• Bone Development

• Joints

• The Skeleton• Macroscopic Skeleton (Axial & Appendicular)• Microscopic Skeleton (Organic & Inorganic matter)

• Joints The place where two or more bones meet.

• Supports the body, provides protection for the internal organs, and enables movement.

• Consists of 206 bones.• Early in development, the skeleton is mostly

cartilage and then the deposition of calcium and other minerals harden the bone.

• There are joints in the skeleton that fastens the bones.

The 206 Bones of skeleton are divided into two types

• Axial Skeleton (80 Bones)

• Appendicular Skeleton (126 Bones)

Cranial Vault

Face Vertebral Column

Rib Cage

Paired Unpaired

Parietal 2

Temporal 2

Frontal 1

Occipital 1

Sphenoid 1

Ethmoid 1

Paired

Hyoid

AuditoryOssicles

Unpaired

Maxilla 2

Zygomatic 2

Palatine 2

Nasal 2

Lacrimal 2

Inferior Nasal 2

Mandible 1

Vomer 1

Malleus 2

Incus 2

Stapes 2

Cervical Vertebrae 7

Thorasic Vertebrae 12

Lumbar Vertebrae 5

Sacrum 1

Coccyx 1

Ribs 24

Sternum 1

Humerus 2

Radius 2

Ulna 2

Carpals 16

Metacarpals 10

Phalanges 28

Upper Limb

Lower Limb

Scapula 2

Clavicle 2

Pelvic Girdle

Coxa

Femur 2

Tibia 2

Fibula 2

Patella 2

Tarsals 14

Metatarsals 10

Phalanges 28

Pectoral Girdle

Axial Skeleton

AppendicularSkeleton

Bone is Made up of

The Compact Bone (Hard Outer Covering)

• Consist of dense Connective Tissues• Provides a Great deal of support

The Spongy Bone• Loosely structured network of separated

connective tissues.• Contain Cavities

• Tough exterior membrane that surrounds the bone.

• Provides protections to the bone.

• Contains many blood vessels that supply nutrients to the bone.

Periosteum

• Soft tissue, that filled in some cavities of spongy bone.

• Red bone marrow begins the production of all blood cells and platelets.

• Yellow bone marrow found in the hollow interior of long spongy bone.

• Yellow bone marrow consist mostly of fat, which stores energy.

• Narrow, Hollow structure surrounded by the concentric rings of new bone cells.

• Extends down to length of the bone.

• Contain blood vessels that enters through the Periosteum.

• Long Length is greater than breadth Examples: Humerous, Femur

• Short Length is equal to breadth Example: Wrist, Ankle

• Flat Thin, Flattened Example: vault of the Skull, Scapulae

• Irregular Example: Vertebrae, Facial bones

• Seasamoids Small nodules of bone Example: Patela

• Organic Matter: 35% CELLS: OSTEOBLAST BONE FORMING CELLS

OSTEOCLASTS BONE DISOLVING CELLS

OSTEOCYTES BONE MAINTAINING CELLS

POLISACCARIDES TO FORM GROUND SUBSTANCE COLLAGEN FIBERS TENSILE STRENGHT

• Inorganic Matter: 65% HYDROXYAPATITE- CALCIUM + PHOSPHATE SALTS THAT MAKE THE BONE HARD

• Site where two or more bones meet.

• Pads of Cartilage cushion are there at the end of the bone of articular joints.

• Joints are classified into three main typesi. Fibrous joints (Immoveable Joints)

ii. Cartilagenous joint (Slightly moveable joints)

iii. Synovial joint (Freely moveable joints)

• Tight Joints.

• Permits little or no movement like the Sutures of the Vault of Skull.

• Articulating surface of the bones of the joint are joined by the fibrous tissue.

• Permits limited movement.

• Divided into two main typesi. Primary:

– Bones are united by plates or bars of hyaline cartilage e.g. union between Ribs and Sternum

ii. Secondary:

– Bones are united by plate of fibrocartilage.– Articular surface covered by thin layer of hyaline cartilage e.g. joints of

vertebral bodies and symphysis pubic

• Permits free movements.

• Articular cartilage covered by thin layer of hyaline cartilage

• Cavity of the articular cartilage is lined by synovial membrane.

• Synovial fluid by synovial membrane lubricates the surface of the articular cartilage.

Joints Type of movement Example

Hinge Joint Bending and Straightening

Elbows, knuckles of fingers and toes

Pivot Joint Rotation Top of Spine

Condyloid Or Gliding joint

Sliding motion Wrist and ankles

Saddle joint Rotation, Bending, and straightening

Base of Thumbs

Ball & Socket joint All types Shoulders and hips