Chapter 6 - Skeletal system Flashcards
Functions of skeletal system
-Support
-Protection
-Movement
-Storage
-Blood cell production
Perichondrium
-Double layered CT sheath
-Covers cartilage except at articulations
Appositional articular cartilage
New chondrocytes and new matrix at the periphery
Interstitial articular cartilage
Chondrocytes within the tissue divide and add more matrix to the cells
Woven bone
-Collagen fibers are randomly oriented
-Formed during fetal development and fracture repair
Lamellar bone
-Mature bone
-In sheets (lamellae)
-Fibers in one direction per layer, different directions across layers
Perforating/Volkmann’s Canal
-Perpendicular to long axis
-Contains blood vessels
-Deliver blood to central canals
Endosteum
-Similar to periosteum, but more cellular
-Lines all internal spaces, including spaces in spongy bone
What bones does intramembranous ossification form?
-Many skull bones
-Parts of mandible
-Diaphyses of clavicle
What bones does endochondral ossification form?
-Bones of the base of the skull
-Part of mandible
-Epiphyses of clavicle
-Most of remaining bones
Zones of epiphyseal plate
-Zone of resting cartilage (slowly dividing chondrocytes)
-Zone of proliferation (new cartilage produced on epiphyseal side of plate, chondrocytes form stacks of cells)
-Zone of hypertrophy (chondrocytes mature/enlarge)
-Zone of calcification (matrix is calcified, chondrocytes die)
-Ossified bone (cartilage on diaphyseal side of plate is replaced by bone)
Vitamin D
-Necessary for absorption of calcium from intestine
-Lack could cause rickett’s or osteomalacia
Vitamin C
-Necessary for collagen synthesis by osteoblasts
-Lack could cause scurvy
PTH
-Stimulated by low calcium in blood
-Activates/increases number of osteoclasts
-Also promotes effects of calcitrol
