Classification of Bone Shapes.docx - Classification of Bone...

Classification of Bone Shapes (6)
1. Flat Bone
2. Long Bone
3. Short Bone
4. Irregular Bone
5. Sutural Bone - minor
6. Sesamoid Bone - minor
Flat Bones
Are thin and flattened bones. They possess a broad flat surface for muscle attachment
or protection of underlying organs.
Include: sternum, ribs, scapula and certain skull bones.
Long Bones
Longer than wide. Have a shaft and bulbus ends
found in upper and lower limbs
Include: Humerus, clavicle, Radius, Ulna, femur, tibia, fibula, metacarpals, metatarsals,
and phalanges.
Long portion = Diaphysis,
Widens = Metaphysis,
End = Epiphysis.
Diaphysis
Elongated shaft of a long bone.
usually cylindrical shaft
Provides leverage and weight support
Compact bone with thin spicules of spongy bone extending inward
Metaphysis
Flared portion of a long bone, between the diaphysis (shaft) of the bone and the
epiphyseal plate at the end of the bone.
Epiphysis
End of a long bone.
Knobby region at each end of long bone
Composed of outer thin layer of compact bone & inner region of spongy bone
In adults, the epiphyseal line, is the remnant of the epiphyseal plate
Short Bones
Cubed-shaped. Texture is spongy except for the thin layer of compact bone at the
surface. Found in wrist and ankle
Length nearly equal to width
E.g., carpal bones (wrist bones), tarsals (foot bones), sesamoid bones (bones along
tendons
of some muscles), patella (kneecap)
Irregular Bones

5 Functions of Skeletal System
1. provide shape & support
2. enable movement
3. protect internal organs
4. hemopoiesis- stem cells produces blood cells
5. stores certain materials until body needs them (fats, calcium)
3 Types of Skeletal Cartilage
hyaline, elastic, fibrocartilage
Hyaline Cartilage
Attaches ribs to sternum
Covers ends of some
bones (articular)
Cartilage within growth plates
Forms the larynx, the costal cartilages of the ribs, and the embryonic skeleton, firm,
structurally amorphous matrix heavily invaded with fibers; appears glassy and smooth.
Elastic Cartilage
Cartilage with abundant elastic fibers; more flexible than hyaline cartilage., Found in ear,
epiglottis, Eustachian tube, eu-nose.
Fibrocartilage
A weight-bearing cartilage that withstands compression; forms the intervertebral discs,
the pubic symphysis & cartilage pads of the knee joints (menisci).
Spongy Bone
Layer of bone tissue having many small spaces and found just inside the layer of
compact bone.
Cancellous or trabecular bone
Located internal to compact bone
Appears porous
20% of bone mass
Compact Bone
Hard, dense bone tissue that is beneath the outer membrane of a bone.