A&P 1 - CH6 - 1 of 2
Terms
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- What are the functions of the Skeletal system?
- Support, protection of internal organs, complex moevement, mineral storage, blood formation (Red blood marrow), and storage of energy (yellow blood marrow)
- The tissues that make up the Skeletal system are what?
- Bone tissue, dense CT, cartilage, epithelial, adipose and nervous.
- What is Red Bone Marrow made of?
- Developing blood cells,adipocytes, fibroblasts and macrophages in a network of reticular fibers.
- What is the function of Red Bone Marrow?
- Produces RBC, WBC and platelets through a process called homeopoiesis.
- Homeopoiesis
- Hemo=blood, poiesis=making, blood producing
- What is the shaft, or body of a long bone called?
- Diaphysis
- What are the distal and proximal ends of long bone called?
- Epiphysis
- The region in a mature bone where the diaphysis joins the epiphysis.
- The Metaphysis
- Which are the only bone cells that undergo cell division?
- Osteogenic cells (or Osteoprogenitor cells) They develop into osteoblasts
- Where are Osteogenic cells found?
- In the inner layer of periosteum and endosteum.
- What are Oseteoblasts?
- Bone-building cells that form the matrix.
- What are Osteocytes?
- Mature cells that no longer secrete matrix, no longer divide.
- What are Osteoclasts?
- Huge macrophage cells in the bone that neccesary to maintain blood calcium levels. They do this by "eating" the bone and depositing Ca into the blood.
- Epiphyseal Line
- Where the epiphysis fuses to the diaphysis. Signals the end of growth of cartilage in long bone and the closure of the growth plate. Still visible in adult x-rays.
- What is the Epiphyseal Plate?
- The clear separation between the epiphysis and diaphysis in long bone. Made of hyaline cartilage, this is an active growing region.
- Characteristics of Articular Cartilage?
- Bone to bone cartilage, Made of hyaline, found only in joints that move.
- Characteristics of Periosteum?
- -Made of dense irregular CT -very vascular, highly innervated. -osteoblast & osteoclast activity for bone remodeling -Sharpey's fibers anchor to bone matrix -insertion points for ligaments and tendons.
- Where is Periosteum found?
- It sheaths the outer surface of long bones,excluding the ends which are covered by articular cartilage.
- Medullary Cavity
- Found only in long bones, filled with yellow marrow. (fat storage)
- Where is Endosteum found?
- It lines internal bone structures, trabeculae & central canals, medullary cavity.
- A bone's hardness depends on crystallizeed inorganic salts, but what gives it flexibility?
- Collagen fibers
- Composition of Bone Matrix
- 35% Organic stuff: cells, fibers, ground substance (protein glycans & glcoproteins) 65% Inorganic stuff: calcium phosphates, calcium carbonate H2o
- Ratio of Spongy bone to compact/cortical/dense bone?
- 80% compact 20% dense
- Blood vessels,lymphatic vessels & nerves from the periosteum use these to pentetrate compact bone.
- Perforating or Volkman's canals
- Osteons or haversian systems
- The repeating units in compact bone. 6-10 concentric rings compressed together, central canal in center.
- Perforating Canals
- Transverse channels that sperarate superior from inferior osteons.
- Central Canals
- In the center of the osteon, passageways for blood vessels, they run longitudinally through the bone.
- Concentric Lamellae
- 6-10 layers of lamellae around the central canalof the osteon, look like rings of a tree trunk.
- Canaliculi
- these little canals radiate in all directions from the lacunae of osteocytes. they transport ions, nutrients, gases as well as removing wastes. Smaller than blood cells, no blood can get through these!
- Interstitial lamellae
- The 'stuffing' filling in between the cells. Fits in between osteons.
- Circumferential Lamellae
- Encircles the entire bone just beneath the periosteum. 3-4 layers thick.
- Functions of Spongy Bone
- Reduces weight of bone resists compression site of red marrow production
- Composition of Spongy Bone
- NO TRUE OSTEONS Consists of lamellae arranged in an irregular lattice of thin columns called trabeculae
- What happens when a Haversian canal gets blocked?
- Osteocytes die from lack of nutrients.
- Intramembranous ossification
- Bone forms direcrly within mesenchyme arranged in sheetlike layers that resemble membranes.
- In this type of bone formation, there is no cartilagenous model.
- Intramembranous ossification
- Examples of bones are formed by Intramembranous ossification?
- Flat bones of the skull mandible, clavicles