1. GENERAL OSTEOLOGY COMPOSITION OF THE LIMBS DR ANDREA D SZÉKELY

2. THE LOCOMOTOR APPARATUS COMPONENTS AND FUNCTION Skeleton - a complex hard structure - mesenchymal origin - mechanical significance. The term skeleton comes from a Greek word meaning “dried up”. NB: All the bones and articulations of the body belong to the passive part of the locomotor apparatus.

3. THE SKELETON The science concerned with the study of bones is termed osteology. The skeletal system of an adult is composed of approximately 206 bones. Each bone is an organ of the skeletal system. For the convenience of study, the skeleton is divided into axial and appendicular parts.

4. THE AXIAL SKELETON Axial division –Skull and associated bones Auditory ossicles Hyoid bones –Vertebral column –Thoracic cage Ribs sternum

5. THE APPENDICULAR SKELETON The appendicular skeleton is composed of 126 bones of the upper and lower limbs and the bony girdles, which anchor the appendages to the axial skeleton. The shoulder girdle (scapula and clavicle) The upper limb (humerus, ulna, radius and bones of the hand) The pelvic girdle (two hip bones and the sacrum) The lower limb (femur, tibia, fibula and bones of the foot

6. THE BONE AS AN ORGAN Bone (os) - one of the hardest tissues of the body. It possesses also a certain degree of toughness and elasticity due to the mineral and fibrous contents. TYPES  compact bone  spongious bone The names imply that the two types differ in density, or how tightly the tissue is packed together. There are three types of cells that contribute to bone homeostasis. a)osteoblasts are bone-forming cell b)osteoclasts resorb or break down the bone c)osteocytes are mature bone cells. An equilibrium between osteoblasts and osteoclasts maintains the bone tissue.

7. FINE STRUCTURE OF BONE CORTICALIS Compact tissue - dense in texture and it is always on the surfaces of the bone. SPONGIOSA fibers and lamellae joining to form a reticular structure, it is found in the epiphysial sites, contains. bone marrow ATTACHMENT SITES Cancellous tissue - consists of collagen fibers and lamellae forming crests or protrusions

10. THE SPONGY BONE TISSUE Spongy bone is lighter and less dense than compact bone. Spongy bone consists of plates (trabeculae) and bars of bone adjacent to small, irregular cavities that contain red bone marrow. The canaliculi connect to the adjacent cavities, instead of a central haversian canal, to receive their blood supply.

11. PERIOSTEUM External surfaces are covered by periosteum (except for articular surfaces). The periosteum adheres to the surface of the bones. It consists of two layers united closely: a)The outer fibrous layer The inner, bone- forming layer

12. The interior of each long tubular bone of the limbs presents a cylindrical cavity named marrow cavity and it is lined with the medullary membrane called endosteum.

13. BIOLOGICAL FUNCTIONS OF THE SKELETON a)Haemopoiesis b)Mineral storage.

14. MECHANICAL FUNCTIONS OF THE SKELETON a)Support b)Protection Based on the property to define body cavities to protect the vitally important organs. The skull and vertebral column enclose the central nervous system. The thoracic cage protects the heart, lungs, great vessels, liver and spleen. The pelvis supports and protects pelvic organs. Blood cells are produced is protected within the central spaces of certain bones.

15. BODY MOVEMENTS Bones serve as anchoring attachments for most skeletal muscles. In this capacity, the bones act as levers, with the joints functioning as pivots, when muscles, which are regulated by the nervous system, contract to cause the movement.

16. CLASSIFICATION OF BONES TUBULAR BONES a) Long tubular bones humerus, radius, ulna, femur, tibia, fibula b) Short tubular bones metacarpal, metatarsal bones and phalanges

17. a) Long spongy bones sternum ribs, etc b) Short spongy bones carpal and tarsal bones c) Sesamoid bones knee-cap pisiform bone, etc. CLASSIFICATION OF BONES SPONGY BONES

18. Skull bones Bones of the vault of the skull Girdle bones The scapula The hip bone, etc. CLASSIFICATION OF BONES FLAT BONES

19. The vertebrae are mixed, or irregular bones The bodies are composed of spongy bones, but the arches and processes are flat CLASSIFICATION OF BONES IRREGULAR BONES

20. PRIMARY CENTERS OF OSSIFICATION In the second month of the intrauterine life, the primary points of ossification appear first, in the shafts, or diaphyses of tubular bones, and in the metaphyses. They ossify by perichondral and endochondral osteogenesis.

21. SECONDARY AND ACCESSORY POINTS OF OSSIFICATION The secondary points of ossification appear shortly before birth or during the first years after birth and they develop by endochondral osteogenesis. The accessory points of ossification appear in children, adolescents, and even adults in the appophyses of bones (e.g. tubercles, trochanters, the accessory processes of the lumbar vertebrae).

22. BONE SURFACE MARKINGS Foramen = opening (arteries, nerves) Fossa = shallow depression Sulcus = shallow groove (artery or nerve) Canal = longer, tubelike opening Fissure = narrow, cleftlike opening Notch = indentation at the end of a bone Meatus = type of canal Condyle = large, round protuberance, attachment of muscles Epicondyle = above or upon a condyle Facet = smooth flat articular surface Trochanter = very large projection Tuberosity = large, rounded, roughened projection Tubercle = rounded eminence/elevation Crest = roughened border or ridge Spine = sharply pointed projection

23. SHOULDER GIRDLE ARM ELBOW FOREARM SHOULDER JOINT WRIST HAND UPPER LIMB

24. THE LOWER LIMB HIP JOINT THIGH KNEE JOINT CRUS ANKLE JOINT PELVIC GIRDLE FOOT