Untitled Quiz

Study Notes

Provides support for the body, soft tissues, and organs
Stores minerals like calcium and phosphate
Yellow bone marrow stores lipids
Red bone marrow inside long bones produces red blood cells, white blood cells, and platelets
Protects vital organs like the heart, lungs, brain, and spinal cord

Bones are classified by shape, bone markings, and internal tissues.
Five shapes: long, flat, irregular, short, and sesamoid.
Long bones such as femur and humerus are found in arms, legs, hands, and feet.
Flat bones like the skull, sternum, ribs, and scapula are thin with parallel surfaces.
Irregular bones are complex shapes like vertebrae and pelvic bones.
Short bones like the ankles and wrist bones are small and thick.
Sesamoid bones are small and flat, found inside tendons near joints like knees, hands, and feet.
Bone markings are depressions, projections, and tunnels that serve specific functions.
Depressions and grooves along the bone surface provide pathways for blood vessels and nerves.
Projections are points where tendons and ligaments attach, or points of articulation (joining) with other bones.
Tunnels allow blood vessels and nerves to enter the bone.

Diaphysis (shaft) of the bone is composed of compact bone with a marrow cavity inside containing bone marrow.
Epiphysis (ends) of the bone are wider and made of spongy bone. They are the points where the bone articulates (joins) with other bones.
Metaphysis is the region between the diaphysis and epiphysis.

Dense matrix composed of calcium salts and bone cells.
Bone cells are located within cavities called lacunae and organized around blood vessels.
Canaliculi connect lacunae, providing pathways for blood vessels and exchange of nutrients and waste.
Calcium phosphate is the main mineral component of bone, constituting 2/3 of the bone matrix.
Collagen protein fibers make up 1/3 of the bone matrix.

Only 2% of bone mass is composed of cells.
Osteocytes are mature bone cells that maintain the bone matrix by regulating its protein and mineral content and helping repair damage. They do not divide.
Osteoblasts are immature bone cells that secrete matrix compounds (osteogenesis), building new bone.
Osteoprogenitor cells are immature cells that can differentiate into osteoblasts. They are responsible for bone growth and repair.
Osteoclasts are responsible for breaking down bone tissue, called bone resorption, to release minerals or to remodel bone.

Compact bone has a dense, solid appearance. It contains parallel osteons (structural units of bone).
Osteons are composed of concentric layers of osteocytes surrounding a central canal containing blood vessels.
Spongy bone is lighter with a lattice-like structure called trabeculae. Trabeculae are meshworks of supporting fibre bundles that provide strength with minimal weight.