Growing end of long bones | Types of epiphysis | Blood supply of long bones | Types of Ossification

General Anatomy of Young Long Bones Miniature long bones Short bones TYPES OF OSSIFICATION Intramembranous Ossification example flat bones of cranial vault and clavicle Enchondral Ossification: example is Ossification of long bones and most of the irregular and other bones IMMATURE OR YOUNG BONES Diaphysis: Cortical bone, compact bone, dense bone, hervasian bone, lamellar bone Hervasian canal Volkman's canal Nutrient foramen Nutritional artery Metaphysis Hair pin like capillaries Osteomyelitis Physis made up of Hyaline cartilage Growth plate Primary cartilagenous joint Synostosis or natural fusion of Epiphysis with metaphysis Epiphysis made up of cancellous bone or spongy bone or trabecullar bone ADULT BONES Upper end or head of long bones Shaft of long bones Lower end or base of long bones BONE CELLS Osteoblasts are bone forming cells laying down osseous tissue called calcium hydroxyapatite Osteocytes are mature bone cells Osteoclasts are Giant cells which are multinucleated and are bone scavenger cells or bone remodelling cells TYPES OF EPIPHYSIS WITH EXAMPLES PRESSURE EPIPHYSIS Weight bearing, covered by articular cartilage and participate in joint formation. example is head of femur, head of humerus, condyles of femur, condyles of tibia TRACTION EPIPHYSIS at the site of attachment of muscles or Ligaments. example is tubercles of humerus, trochanters of femur, epicondyles of humerus ATAVESTIC EPIPHYSIS Piece of bone which was a separate bone gets fused to other bone. example is coracoid process of humerus and Os trigonum of talus ABERRAT EPIPHYSIS or SUPERANUMERARY EPIPHYSIS Epiphysis which is not normally present. example is epiphysis at the base of metacarpals or metatarsals or bipartite patella GROWING END OF LONG BONES is 1. In the fetal lying position the end of the long bone nearer to the head is the Growing end 2. The Growing end of a long bone is always opposite to the direction of nutritional foramen or the direction of nutritional artery entering the long bone 3. Generally Growing end is the bulkier end of a long bone. except clavicle (reason is opposite end is a traction epiphysis and Growing end is free not a pressure epiphysis, further proximal end of ulna is the weight bearing end) 4. Law of Ossification states that the secondary Ossification centre is first to appear at the growing end and is last to fuse. Except Fibula (In fibula secondary Ossification centre is first to appear at the opposite end that is lower end which is not the Growing end reason being lower end of fibula is weight bearing and an example of pressure epiphysis. But fusion of fibula takes place according to the law of Ossification that the opposite end lower end is first to fuse because the upper or proximal end is the Growing end it has to keep Growing to keep up the length according the the growth in the length of tibia) PRIMARY OSSIFICATION CENTRE SECONDARY OSSIFICATION CENTRE Generally appears after birth. except at the lower end of femur and upper end of tibia (growing end of femur & tibia) which participate in forming knee joint GROWING END OF LONG BONES 1. Growing end of clavicle is the medial or sternal end 2. Growing end of humerus is the upper end or proximal end 3. Growing end of radius and ulna is the lower end or distal end 4. Growing end of femur is the lower end or condylar end or the distal end 5. Growing end of tibia and fibula is the upper end or proximal end BLOOD SUPPLY OF LONG BONES 1. Blood supply to clavicle and scapula is by a nutritional branch of suprascapular artery 2. Blood supply to humerus is by a nutritional branch of brachial artery 3. Blood supply to both Radius and Ulna is by A nutritional branch of Anterior interosseous artery major branch of common interosseous artery which is the largest branch of ulnar artery in forearm 4. Blood supply to femur is by the 2nd perforating branch of profunda femoral artery. the 1st perforating branch of PFA participates in cruciate anastomoses at the back of thigh 5. Blood supply to Tibia is by a nutritional branch of posterior tibial artery 6. Blood supply to fibula is by a nutritional branch of peroneal or fibular artery which is the largest and longest branch of posterior tibial artery DIRECTION OF NUTRITIONAL FORAMEN IN LONG BONES 1. Nutritional foramen in clavicle is directed laterally 2. Nutritional foramen in humerus is directed downwards or distally 3. Nutritional foramen in radius is directed upwards or proximally 4. Nutritional foramen in ulna is directed upwards or proximally 5. Nutritional foramen in femur is directed upwards or proximally 6. Nutritional foramen in tibia is directed downwards or distally 7. Nutritional foramen in fibula is directed downwards or distally By Dr. SAM Professor of Human Anatomy OSPE in ANATOMY for practical and spotting exam preparation    • OSPE - ANATOMY by Dr. SAM