Flashcards in Lecture 9- Bone Deck (45)
What type of bone will initially be formed at the growth plate?
Woven bone. Later remodeled into lamellar bone.
When is full stature obtained?
When the epiphyses have fused (fully ossified, no more cartilage there)
Which type of bone would you see in a new fracture and healed fracture?
1. Woven Bone
2. Lamellar Bone
*Fractures heal quickly, woven bone is layed and remodeled
What general things affect bone formation/turnover?
1. Major Systemic Regulators
2. Stress on the bone
What are the major systemic regulators of bone formation/turnover? (7)
1. Parathyroid Hormone (PTH)
2. Calcitrol (vit. D)
4. Growth hormone/ IGF - 1
6. Thyroid Hormones
*First 3 are most important*
What is the main function of Vitamin D?
Increase Ca absorption from the gut
Main function of PTH?
Released when serum Ca low
*Stimulates osteoclast activity to raise serum Ca
What would a happen with deficiency of PTH?
Remodeling process would not be stimulated
What does excess growth hormone in an adult result in and why?
Periosteal growth happens b/c you do not have endochondral ossification as an adult
What does excess growth hormone in a child result in and why?
Endochondral ossification at the epiphyseal plate
What does insufficent growth hormone in a child result in?
What are the components of the joint capsule?
1. Fibrous Layer
2. Synovial Membrane
What is the orientation of collagen fibers in Articular Cartilage?
Curved fibers. Perpendicular to surface near the bone and parallel to surface neaer the surface.
What is the advantage of curved fibers in articular cartilage?
Pressure is more evenly distributed, helps protect the chondrocytes from deformation.