chap 6-bone and skeletal tissue.pdf

Chapter 6: Bone and Skeletal Tissues ”I have a bone to pick.”  LO Identify the three types of cartilages and be able to compare and contrast them with regards to what is found in them and where they are found Explain the functions of bon...

Chapter 6: Bone and Skeletal Tissues ”I have a bone to pick.”  LO Identify the three types of cartilages and be able to compare and contrast them with regards to what is found in them and where they are found Explain the functions of bones Able to explain the types of bones and give multiple examples of each Identify and articulate what are all the types of markings found on bones Explain difference between compact and spongy bone Explain what substances make up a bone, including what makes it so hard  LO Identify and explain what are the cell found in bones Explain parts of bone from a histological perspective Able to explain the difference between intramembranous and endochondral ossification Explain the difference between interstitial and appositional bone growth Explain what rickets are Explain what osteoporosis is, who gets it, how to treat it and how to diagnosis it.  Cartilages Articular Cartilage Nose Joints Ear Sternal Cartilage Intervertebral discs Pubic symphysis Respiratory tubes Epiglottis Articular discs  Types of Cartilages Three types of cartilages Hyaline Elastic Fibrocartilage All three types contain: Chondrocytes Abundant extracellular matrix Lacuna  Hyaline Cartilage Most abundant Resists compression due to: Inside matrix will only be _______ fibers Found in: 1) 2) 3)  Hyaline Cartilage Most abundant Resists compression due to: large amount of H20 Inside matrix will only be collagen fibers Found in: 1) Articular Cartilage 2) Sternal Cartilage 3) Holds airways open in respiratory system  Elastic Cartilage Matrix contains elastic and collagen fibers Function: tolerate repeated bending Found in: Epiglottis Ear Auditory Tube  Fibrocartilage Contains thick collagen fibers that surround the chondrocyte Dense irregular CT Function to resist compression and pulling forces Found in the: Intervertebral disc Articular discs between joints  Functions of Bones Support  Functions of Bones Support Movement due to tendons  Functions of Bones Support Movement Protection  Functions of Bones Support Movement Protection Mineral storage  Functions of Bones Support 325 × 280 Movement Protection Mineral storage Blood cell and fat storage  Functions of Bones Support 325 × 280 Movement Protection Mineral storage Blood cell and fat storage Energy metabolism  Bone Classification Long Short Sesamoid Flat Irregular Sutural Long Bone Short Flat Irregular Compact vs Spongy Bone  Gross Anatomy of the Long Bone Diaphysis Epiphysis Epiphyseal line Periosteum Dense irregular connective tissue Osteogenic layer Osteoblast/osteoclasts Articular cartilage Endosteum  Flat bones Compact bone Spongy bone= diploë  Bone Composition Organic Inorganic (hydroxyapatites) Contains mostly collagen Calcium phosphate Produced by osteo_____ Contributes to bone being hard Contributes to: and resisting _________ forces.  Bone Composition Organic Inorganic (hydroxyapatites) Contains mostly collagen Calcium phosphate Produced by osteoblasts Contributes to bone being hard Contributes to: the flexibilty and and resisting compression forces. tensile strength that allow bone to resist bending and twisting. Approx 35% of the bone weight is due to the organic composition.  Bone Cell Types Osteogenic cell Osteoblasts osteoid Osteocyte Osteoclast PTH role  Histology of Compact Bone Osteon (Haversian system) Lamellae Central canal (Haversian canal) Perforating canals (Volkmann’s canal) Lacunae Canaliculi Circumferential lamellae Histology of Spongy Bone  Review 1) What are the four cell types found in bone. 2) Describe the structure of a osteon (Haversian system). 3) Label the parts A C B  Bone Ossification Begins at 8th week of embryo development Intramembranous ossification Bone formed from fibrous membrane Skull and clavicle Endochondral ossification Bone from hyaline cartilage replaced Intramembranous Ossification Endochondral Ossification  1st Step Starts as cartilage model Perichondrium is invaded by blood vessels to form _______ Osteoblasts in periosteum form bone collar  1st Step Starts as cartilage model Perichondrium is invaded by blood vessels to form periosteum Osteoblasts in periosteum form bone collar  2nd Step Cartilage in the middle of the diaphysis hardens leaving a cavity  3rd Step Periosteal bud invades cavity Trabeculae/spongy bone formed due to osteoblast activity Primary ossification center  4th Step Diaphysis continues to grow Medullary cavity formed After birth: Epiphysis becomes spongy bones when bud enters the epiphysis Secondary ossification centers  5th Step Epiphysis completes ossification Hyaline cartilage only at surfaces of epiphysis and the epiphyseal plate  Bone Growth Interstitial Appositional  Interstitial Bone Growth Bone will continue to grow in length as long as cartilage will equal bone conversion. Puberty  Appositional Growth At periosteum osteoblasts At endosteum osteoclasts Types of Fractures Types of Fractures Types of Fractures  Osteoporosis Due to low bone mass Bones become porous and thinner. Most vulnerable at vertebral column and neck of femur. Who gets it? Why do you get it? How detect? How to treat?  Paget’s Disease Chronic bone disease Excessive rates of bone deposition and bone reabsorption Immature bone Later stages bones become thick Not life threating  Rickets Form of osteomalacia but in children Bones not fully calcified so becomes soft Due to: 1) Low calcium phosphate 2) Low amounts of Vit D