Presentation on theme: "SAP2b: Relate structure and function in skeletal system Warm Up: Brief definition of these terms: pg 134: axial skeleton, appendicular skeleton, compact."— Presentation transcript:
SAP2b: Relate structure and function in skeletal system Warm Up: Brief definition of these terms: pg 134: axial skeleton, appendicular skeleton, compact bone, spongy bone, Classwork: Introduction to skeletal system; color sheet bone structure Closing: discussion of bone types Anatomy November 6th
The Skeletal System Chapter 6
System Functions: Support (bones, cartilage, ligaments) Protection (ribs & skull) Movement (muscle to bone by tendons) Storage –Calcium & Phosphorus in bone –Adipose in Yellow Bone Marrow Blood Cell Production –in Red Bone Marrow
Made of Connective Tissue with different substances in their Matrix:
Endosteum – thinner connective tissue lining the Medullary Cavity
Osteoblasts – bone forming cells (they originate from the periosteum or from the bone marrow) Osteoclasts – bone removing cells Osteocytes – mature bone cells
Osteoclasts Osteoblasts Osteocytes
Lamellae – thin sheets of bone matrix Lacunae – spaces in bone where osteocytes are located Trabecular is synonymous with Cancellous or Spongy bone.
2 Major Types of Bone Based on their Density:
1.) Compact Bone – mostly solid (dense) cells 2.) Cancellous or Spongy Bone - A Lacy network of bone with small marrow filled spaces
Ossification – Bone Formation By Osteoblasts A matrix of collagen and proteoglycans is laid down by the osteoblasts Osteocytes form (this starts during fetal development & ends around yr of age)
Bone Growth in Length Epiphyseal Plate also called the Growth Plate Composed of cartilage Found between the epiphysis & diaphysis Growth occurs from this point. When growth stops, the plate cartilage is replaced by bone and it is then called the Epiphyseal Line.
New bone lamellae (sheets of bone cells) are deposited onto existing bone Osteoblasts are deposited onto new bone on top of the periosteum, which increases the width. Bone Growth in Width
Allows for bone to restructure and reshape itself to help to maintain bone strength Existing bone removed by osteoclasts & deposition of new bone using osteoblasts Bone Remodeling
Repair of Bone Fractures Bones contain Nerves and Blood Vessels
damages blood vessels within bleeding occurs & a clot forms a fibrous network of connective tissue forms at the break – holding bone together cartilage is added this zone of tissue repair is called the Callus What occurs in a broken bone…
Osteoblasts invade the Callus & forms cancellous bone – taking 4-6 weeks for completion Cancellous Bone is slowly remodeled to from Compact Bone Total healing time requires several months for normal bone strength to return Continued….
Bleeding & clotting occurs Fibrous Connective Tissue & Cartilage is formed. Cancellous Bone forms. Compact bone eventually replaces cancellous bone.