Classification of bones
compact intramembranous axial histology development regional spongy Intra cartilaginous appendicular
flat Irregular shape Sesamoid Long Short Wormian pneumatic
Classification of Bones on the Basis of Shape Figure 5.1 Copyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 5.4c
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.
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
LONG BONE
Long and short bones
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.
SHORT BONE
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
PNEUMATIC BONE
Anatomy People talk so much about me
FLAT BONE
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
What is function of flat bones
FLAT BONE
FLAT BONE
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.
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.
IRREGULAR BONE
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.
WORMIAN BONE
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
SESAMOID BONE
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
INTRAMEMBRANOUS AND INTRACARTILAGINOUS YES I REMEMBER
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
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
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
Second lecture
Bone markings
2. CREST:ridge of bone(iliac crest)
3. Epicondyle Eminence superior to a condyle E.g. lateral epicondyle of humerus
EPICONDYLE OF HUMERUS
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)
5. FORAMEN Passage through a bone(obturator foramen)
6. FOSSA Hollow or depressed area(iliac fossa)
7. GROOVE Elongated depression of furrow(arterial grooves in calvaria)
8. LINE Linear elevation(soleal line of tibia)
9. MALLEOLOUS Rounded process(lateral malleolous of fibula)
10. NOTCH Indentation at the edge of a bone(greater sciatic notch)
11. PROTUBERANCE Projection of bone(external occipital protuberance
12. SPINE Thorn-like process(spine of scapula)
13. Spinous process Projecting spine-like part(spinuous process of vertebra)
14. TROCHANTER Large blunt elevation(greater trochanter of femur)
15. TUBERCLE Small raised eminence(greater tubercle of humerus)
16. TUBEROSITY Large rounded elevation(ischial tuberosity)
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
SPUR