The Basics

BONE:

Properties:

• Highly Vascular
• Connective Tissue
• Strong
• Durable
• Light
• Dynamic

Functions:

• Support
• Movement
• Protection
• Mineral Storage
• Haemopoesis 
• Energy Storage

Composition:

• Organic - Collagen Fibres which provides resistance and resilience
• Inorganic - Hydroxyapite crystals for strength 

Classification:

• Trabecular Bone - Trabeculae is orientated so stress is evenly beared
• Cortical Bone -Various thickness

Long Bones:

Humerous, Radius, Ulna, Femur, Tibia, Fibula, Metacarpals and Metatarsals. 

• Distribute stress evenly 
• Slightly curved
• Trabecula at epiphysis 
• Cortical throughout shaft

Short Bones:

Carpals and Tarsals

• Cube Shaped
• Trabecula 
• Thin layer of Cortical

Flat Bones:

Cranial Bones, Sternum, Ribs and Scapula

• Protection/attachment
• Trabecula
• Thin layer of Cortical

Irregular Bones:

Vertebrae and some facial bones

• Varying ratios of Cortical to Trabecular

Sesamoid Bones:

Bipartite Patella and Pistiform

• Found inside tendon where it passes over a joint

Bone Surface Markings:

Trocanter, Tuberosity and Tubercle

• Transmit nerves and vessels
• Sulcus, Foramen, Fissure

Ossification

The process by which connective tissue is replaced by bone.

Intramembranous Ossification:

Skull bones

• Occurs in loose connective tissue membranes

Endochondrial Ossifcation:

Long Bones

• Formation occurs in hyaline models
• Perichondral cells differentiate into Osteoblasts
• Occurs in long bones at 8th week of intrauterine life

Epiphysal plate:

Real People Have Careers

Vertically:

Resting

Proliferating

Hypertrophic

Calcified 

Horizontally:

Periosteal cells differentiate into osteoblast which surround themselves in bone matrix

Normal Variants

Sesamoid, Cervical rib, Spina Bifida Occulta, Idiopathic Scoliosis