Chapter 12: Bone Classification and Structure

Red bone marrow

Occupies spongy bone in some epiphyses and flat bones and produces blood cells

Articular Cartilage

On ends of epiphyses

What are bones composed of?

Bones are composed of a variety of tissues including bone tissue, cartilage, dense connective tissue, blood, and nervous tissue.

Bone extracellular matrix

Collagen and calcium phosphate

Lamella

Concentric ring of matrix around central canal

Central canal (Haversian canal, osteonic canal)

Contains blood vessels and nerves

Osteon (Haversian system)

Cylinder-shaped unit

Flat Bones

Flat bones have wide surfaces, but they are sometimes curved, such as those of the cranium. (Ribs, scapula, most cranial bones)

Compact (dense) bone

Forms diaphysis and epiphyseal surfaces

Epiphyseal Plate

Growth zone of hyaline cartilage

Medullary (marrow) cavity

Hollow chamber

Irregular Bones

Irregular bones have numerous shapes and often have articulations with more than one other bone. (Vertebra, some facial bones as sphenoid)

Long Bones

Long bones are much longer than they are wide and have expanded ends. (Femur, Humerus, Phalanges)

Periosteum

Membrane around bone (except articular cartilage) of dense irregular connective tissue

Canaliculus

Minute tube containing cellular process

Know the structure of a long bone

Proximal epiphysis, Articular cartilage, Epiphyseal lines, Red bone marrow, Compact bone, Yellow bone marrow, Periosteum, Endosteum location, Medullary(marrow) cavity, Spongy bone, Diaphysis, Distal epiphysis,

Sesamoid Bone

Sesamoid bones are small and embedded within a tendon near joints where compression often occurs. (Patella)

Diaphysis

Shaft between epiphyses

Short Bones

Short bones are somewhat cube shaped, with similar lengths and widths. (Carpals, Tarsals)

Lacuna

Small chamber for an osteocyte

Living bone is a combination of about one-third organic matter and two-thirds inorganic matter. What do the organic and inorganic matter consist of?

The organic matter mostly consists of embedded cells and collagen fibers. The inorganic matter is mostly complex salt crystals, hydroxyapatite, consisting of calcium phosphate.

What are the functions of bones?

They support and protect softer tissues, provide points of attachment for muscles, house blood-producing cells, and store inorganic cells.

Endosteum

Thin membrane lining medullary cavity of reticular connective tissue

Spongy (cancellous) bone

Within epiphyses trabeculae - a structural lattice of plates in spongy bone

Yellow bone marrow

occupies medullary cavity and stores adipose tissue