CHAPTER 6 Bone Tissue Functions of Bones and the Skeletal System Support Protection Assistance in movement Mineral storage and release Blood cell production Triglyceride storage Types of Bones Long bones femur longer than they are wide Short bones wider than they are long carpel trapezoid Flat bones contains layer of compact bone spongy bone compact bone diploe Irregular bones vertebre Sesamoid bones usually develop along tendons Types of Bones Hemopoesis production of RBC that occurs in red bone marrow Parts of a Long Bone Diaphysis body shaft of bone Epiphyses has proximal distal ends Metaphyses has proximal distal ends growth plate region Articular cartilage at ends of long bones b c they are going to epiphyseal line lies here articulate with other bones Periosteum tough membrane that covers the bone makes them kindof slippery 2 layers fiberous dense irregular tissue osteogenic layer provides some nutrition in that bone allows blood vessels to get into that bone Medullary cavity Endosteum lining of the medullary cavity Anatomy of a Long Bone Bone Surface Markings Depressions and openings Fissure narrow slit usually b w adjacent bones Foramen hole largest is where the spinal cord goes through at the back of head lots in skull facial bones Fossa shallow depression associated w muscle contraction Sulcus groove or furrow Meatus tube like passage way or canal auditory meatus ear canal Bone Surface Markings Processes that form joints Condyle large rounded pertuberis sticks out on femur and tibia Facet ribs smooth flat articular surface something is going to touch it Head rounded supports bone the neck of the bone is supported by the head Bone Surface Markings Processes that form attachment points for connective tissues Crest prominent ridge scapula Epicondyle right above a condyle same as but smaller Line long ridge or border difficult to see Spinous process on our vertebrae slender projection Trochanter very large projection Tubercle like line or furrow but has a small nodule on it for the attachment of a tendon Tuberosity large rounded rough projection on femur Bone Tissue Cell Types Osteogenic cells AKA Mesenchyme Cells all cells start as Osteoblasts forms extracellular matrix Osteocytes for maintenance don t divide carries on metabolic activity for the bone Osteoclasts similar to monocytes WBC working with bone reabsorption Bone Tissue Cell Types Given pics at bottom know which is which Histology of Compact Bone Embedded osteocytes are found in the osteon in the lacunae Osteons concentric circular rings of lamellae Central canal Concentric lamellae Lacunae Canaliculi passageway filled w extracellular fluid helps connect one bone cell to another bone cell Interstitial lamellae fills up spaces b w osteons Circumferential lamellae outer space where the osteons have pushed out older osteons The outer ones are the older osteons Perforated canal NAV Nerve artery vein where there s one there s the other Histology of Compact Bone Histology of Spongy Bone Osteoclast for bone absorption Blood and Nerve Supply of Bone Periosteal arteries Nutrient arteries Nutrient foramen Metaphyseal and epiphyseal arteries Blood Supply of a Long Bone Articular cartilage this bone is going to articulate to something else Periosteal artery carry blood to periosteum outer layers of the compact bone Growth plate Metaphyseal artery give blood to the appropriate part of the bone carry to middle ends of long bones Nutrient artery veins carrys blood to the medullary cavity Shaft Draining Blood from Bone Nutrient veins Metaphyseal epiphyseal veins Periosteal veins Bone Formation Intramembranous ossification simpler 4 step Endochondral ossification 6 or 7 step LOTS of questions missed on this know which steps take place under which Intramembranous Ossification Simpler process than endochondral ossification Examples flat bones of the skull Parietal occipital sternum etc Involves a 4 step process Osteogenic cells turn into osteoblasts Development of ossification center osteoblasts secrete organic extracellular matrix You get calcium bone starts to get hard more formation You start to get spaces spongy Development of the periostium Flat bone Flat bone Flat bone Flat bone of skull of skull of skull of skull Mandible Mandible Mandible Mandible Blood capillary Blood capillary Blood capillary Blood capillary Ossification center Ossification center Ossification center Ossification center Mesenchymal cell Mesenchymal cell Mesenchymal cell Mesenchymal cell Osteoblast Osteoblast Osteoblast Osteoblast Collagen fiber Collagen fiber Collagen fiber Collagen fiber 1 1 1 1 Development of ossification center Development of ossification center Development of ossification center Development of ossification center Osteocyte in lacuna Osteocyte in lacuna Osteocyte in lacuna Canaliculus Canaliculus Canaliculus Osteoblast Osteoblast Osteoblast Newly calcified bone Newly calcified bone Newly calcified bone matrix matrix matrix Mesenchyme Mesenchyme condenses condenses Blood vessel Blood vessel Spongy bone Spongy bone trabeculae trabeculae Osteoblast Osteoblast 2 2 2 Calcification Calcification Calcification KNOW 1 4 LOTS OF QUESTIONS Ex Which stage does the periostium lay down 3 3 Formation of trabeculae Formation of trabeculae Periosteum Spongy bone tissue Compact bone tissue 4 Development of the periosteum Endochondral Ossification Cartilage is replaced by bone Examples most bones of the body Involves a 6 step process Mesenchyme chondroblast chondrocytes Copyright 2012 John Wiley Sons Inc Endochondral Growth Length and Width The cartilage model grows in length by mitosis and by the deposition of extracellular matrix In contrast growth of cartilage in thickness is due mainly to the addition of more extracellular matrix to the periphery Events at the Epiphyseal Plate Permits Growth of Long Bones On exam know what these layers are Zone of resting cartilage anchors bone to growth plate Zone of Proliferating cart site of rapid cell division Zone of Hypertrophic cart cells get larger start to stack themselves Calcified cartilage thin zone most cells are dead b c matrix is already calcified Role of the Epiphyseal Plate in Bone Growth The growth in length of a long bone involves Interstitial growth Replacement of cartilage with bone by endochondral ossification on the diaphyseal side of the epiphyseal plate Growth of width appositional Increased Bone Thickness Occurs via Appositional Growth width Remodeling of Bone Bone remodeling on going