Classification and Structure of Bones

Goals for Today 1) Skeletal support system 2) Four bone groups 3) Bone structure 4) Bone markings and their functions

Support System 1. Bone Matrix filled with calcium salts Rigidity from calcium salts Flexibility from collagen fibers Contains osteocytes or “bone cells”

Support System 2. Cartilage Pg. 78 Support System 2. Cartilage Gel-like matrix with fibers such as collagen and elastic fibers Chondrocyte (Cartilage Cells) 3 types

3 types of Cartilage flexible, not sturdy - EX: epiglottis, ear Elastic Cartilage flexible, not sturdy - EX: epiglottis, ear Hyaline Cartilage - sturdy support with some flexibility - EX: nose, trachea, ribs Fibrocartilage sturdy, not as flexible EX: intervertebral disks

Cartilage: Infant vs. Adult Skeleton More cartilage Less cartilage

The 4 Bone Groups Long Bones – longer than wide. EX: femur, humerus Short Bones – cube-shaped. EX: tarsals, carpals Flat Bones – thin and flattened. EX: skull, ribs Irregular Bones – “other bones” EX: vertebrae

Parts of a Bone Epiphyses ends Diaphysis shaft Epiphyseal line Where they meet AKA growth plate Medullary Cavity Contains yellow bone marrow

Epiphyseal (Growth) Plate

Bone Parts Compact bone Dense portion of diaphysis Surrounds yellow bone marrow Spongy bone in epiphysis Contains red bone marrow Membranes Periosteum – outside Endosteum – inside

Microscopic structure of bone Central Canal w/ blood vessels, nerves Lacunae w/ bone cells Osteon

Bone Markings Table 9.1 Vessel Passage Muscle Attachment Joints

Tuberosity Crest