Classification of bones

Transcription

1 Classification of bones

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4 compact intramembranous axial histology development regional spongy Intra cartilaginous appendicular

5 flat Irregular shape Sesamoid Long Short Wormian pneumatic

6 Classification of Bones on the Basis of Shape Figure 5.1 Copyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 5.4c

7 Histological classification. According to structure / architecture Compact bone. It forms the outer shell of the shaft of long bones & vertebrae. Cancellous bone or spongy bone. It is seen internal to compact bones and at the ends of long bones.

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9 ACCORDING TO THE SHAPE Long bones are longer than they are wide, consisting of a long shaft (the diaphysis) plus two articular (joint) surfaces, called epiphyses. Comprised mostly of compact bone, but contain considerable spongy bone and marrow in the hollow centre (the medullary cavity). Most bones of the limbs are long bones. Humerus Radius ulna

10 LONG BONE

11 Long and short bones

12 Short bones are roughly cube-shaped, and have only a thin layer of compact bone surrounding a spongy interior. The bones of the wrist and ankle are short bones, as are the sesamoid bones.

13 SHORT BONE

14 Pneumatic bones These bones are found in the skull. The spongy part of the bone is replaced by airfilled cavities, which communicate with the nose. These air- filled cavities are known as paranasal sinuses. These are found in the frontal, maxillary and sphenoid bones

15 PNEUMATIC BONE

16 Anatomy People talk so much about me

17 FLAT BONE

18 Flat bones are thin and generally curved, with two parallel layers of compact bones sandwiching a layer of spongy bone. Most of the bones of the skull are flat bones, as is the sternum.ribs,scapula

19 What is function of flat bones

20 FLAT BONE

21 FLAT BONE

22 In some cases all of spongy bone is not replaced. As a result the air spaces form a series of small pockets or air cells. These pockets are found in ethmoid bones and mastoid part of temporal bones. In mastoid part of temporal bone these pockets are called mastoid air cells which communicate with middle ear cavity.

23 Irregular bones do not fit into the above categories. They consist of thin layers of compact bone surrounding a spongy interior. As implied by the name, their shapes are irregular and complicated. The bones of the spine and hips are irregular bones.

24 IRREGULAR BONE

25 Wormian or sutural bones Small bones are found along the sutures of the skull where flat bones come together. These are called wormian bones or sutural bones.

26 WORMIAN BONE

27 Sesamoid bones are bones embedded in tendons. Since they act to hold the tendon further away from the joint, the angle of the tendon is increased and thus the force of the muscle is increased. Examples of sesamoid bones are the patella and the pisiform

28 SESAMOID BONE

29 According to development 1.Membranous bones. These bones develop through Intra membranous ossificationmembranous bones include Bones of the vault of the skull Bones of the face and clavicle 2.Cartilaginous bones. These develop by the process of intracartilaginous ossification.. All long bones of the body (except clavicle) vertebrae & short bones develop by this process. 3. Membrano-cartilaginous bones. These develop through both of the above processes. These include

30 INTRAMEMBRANOUS AND INTRACARTILAGINOUS YES I REMEMBER

31 According to region Axial bones (belonging to axial skeleton) Bones of the skull Auditory ossicles Vertebrae Sternum Ribs Appendicular bones (belonging to appendicular skeleton) Bones of the limbs Bones of the shoulder & pelvis girdle

32 The appendicular skeleton consists of the girdles and the skeleton of the limbs. The upper (anterior) limbs are attached to the pectoral (shoulder)girdle and the lower (posterior) limbs are attached to the pelvic (hip) girdle

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34 Long Bones Short Bones Flat Bones Irregular Bones Femur Tarsals Patella Atlas Humerus Carpals Cranium Axis Tibia Ilium Cervical Radius Scapula Thoracic Ulna Sternum Lumbar Fibula Ribs Sacrum Phalanges Clavicle Coccyx Meta Tarsals Meta Carpals

35 Second lecture

36 Bone markings

37 2. CREST:ridge of bone(iliac crest)

38 3. Epicondyle Eminence superior to a condyle E.g. lateral epicondyle of humerus

39 EPICONDYLE OF HUMERUS

40 4. FACET Sooth,flat area usually covered with cartilage where a bone articulates with another bone(superior costal facet on the body of vertebra for articulation of rib)

41 5. FORAMEN Passage through a bone(obturator foramen)

42 6. FOSSA Hollow or depressed area(iliac fossa)

43 7. GROOVE Elongated depression of furrow(arterial grooves in calvaria)

44 8. LINE Linear elevation(soleal line of tibia)

45 9. MALLEOLOUS Rounded process(lateral malleolous of fibula)

46 10. NOTCH Indentation at the edge of a bone(greater sciatic notch)

47 11. PROTUBERANCE Projection of bone(external occipital protuberance

48 12. SPINE Thorn-like process(spine of scapula)

49 13. Spinous process Projecting spine-like part(spinuous process of vertebra)

50 14. TROCHANTER Large blunt elevation(greater trochanter of femur)

51 15. TUBERCLE Small raised eminence(greater tubercle of humerus)

52 16. TUBEROSITY Large rounded elevation(ischial tuberosity)

53 17. SPUR Bony projections that usually form along joints Also known as osteophytes Formed due to damage to joint as age progresses E.G. OSTEOPHYTES OF THE VERTEBRAE

54 SPUR