Bone Growth and Joints Bone growth and remodeling
Bone Growth and Joints
Bone growth and remodeling • Two (three) types of bone: 1. Membrane bone – bone forming within connective tissue (=dermal bone) – Neurocranium (skull), scapula Osteoblasts osteoid trabeculae (small beam)
Types of bone (continued) 2. Cartilage replacement bone 1. Endochondral bone – bone that forms within cartilage 2. Perichondral bone – forms in CT on surface of bone – Long bones
Development of the femur in a late embryo or fetus of a mammal. A– original cartilage being replaced by bone on periphery (perichondral bone) original cartilage being replaced by bone within cartilage (endochondral bone) Blue = cartilage Purple = calcified cartilage Pink = bone
B – enlarged detail of bone formation Blue = cartilage Purple = calcified cartilage Pink = bone
Notes on Joints (articulations) • Structure and function dependent upon: – Degree and direction of movement needed – Forces acting upon the joint – Nature of the material at articulation • C–C • B–B • C–B
Classification based on overall movement and material • Synarthroses – restricted movement – Sutures Periosteum Dermal bone Sutural ligament Dermal bone 1. Coronal suture
Functional synarthroses • Reinforced – look at woodpecker skull Not synarthroses frontal nasal
• Synchondroses
Basioccipital Spheno-occipital Synchondrosis Basisphenoid
• Sympases – Fibrocartilage – Some elastin 1. Symphysis mentalis Pubic symphysis Also: 2. Synchondrosis sphenooccipitalis 3. Synchondrosis intraoccipitalis anterior 4. Fonticulus posterior 5. Synchondrosis intraoccipitalis posterior
Diarthroses (synovial joints) • Lots of movement – Knee – Jaw
Functional Types of Joints Gliding joints
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