Ch. 6 Bone Tissue & The Skeletal System

Please Read Ch. 6 through bone tissue and use the information from Ch Please Read Ch. 6 through bone tissue and use the information from Ch. 6 to fill in the ppt for the Terms below. ALSO: Study the bones on the word document entitled “Bone Assignment after Test 2-2017” Give functions & locations of the 3 types of cartilage Define Axial and Appendicular Skeletons & describe the 5 functions of the Skeletal System Give a brief description of long, short, flat, irregular, and sesamoid bones Define the Bone Marking Classifications: articulations (for joints), projections, and holes (depressions and openings) Give the functions of the following cell types: osteogenic, osteoblasts, osteoclasts, osteocytes Describe the following Bone Tissue items that we previously did in Ch. 4 again: osteon, haversian canal, volkmann’s canal, lacuna, canaliculi, and the lamella that are part of the osteon How are circumferential and interstial lamella different from the lamella in osteons-- describe

I. Introduction Describe the skeletal cartilages and how they grow. A. Parts: bones, cartilage, joints Skeletal Cartilages Perichondrium Types Growth Appositional Interstitial Classification Divisions Axial Appendicular - 206 Bones Describe the divisions of the Skeletal System. Figure 6.1

Describe the bone shape categories and give their general functions. 2. Bone Classification by Shape * See Textbook Table for general functions of each Describe the bone shape categories and give their general functions. (e) Sesamoid bone Figure 5.1

D. The Functions of The Skeletal System Objectives List and describe the functions of the Skeletal System 1. 2. 3. 4. 5. Minerals

II. Bone Structure A. Gross Anatomy 1. Bone Markings * see Table in Textbook a. Articulations b. Projections c. Depressions & Openings 2. Bone Textures a. Compact Bone b. Spongy Bone- Diploë 3. Gross Anatomy of a Long Bone

II. Bone Structure … A. Gross Anatomy … 1. Bone Markings … Table 6.1

3. Structure of a Long Bone A. Gross Anatomy … 3. Structure of a Long Bone a) Epiphysis = Type bone” Epiphysial plate Epiphyseal line b) Diaphysis = Type bone: Medullary cavity & contents:

e) Articular Cartilage c) Periosteum = Structure/Composition: Overall Function: Nutrient foramen d) Endosteum = e) Articular Cartilage

4. Structure of Short, Irregular & Flat Bones A. Gross Anatomy … 4. Structure of Short, Irregular & Flat Bones Spongy bone: Location Compact bone: Location Figure 5.2b

Bone Structure … B. Microscopic Anatomy 1. Cells of Bone Tissue a. Osteogennic cells = Turn into: b. Osteoblasts – make: c. Osteoclasts (derived from WBCs) d. Osteocytes Location Function

d. Osteocytes … Communicate: Can sense stress in bone, then:

2. Bone Tissue a) Compact Bone Function Osteons = Haversian System Haversian, Central Canal Volkmann’s or Perforating Canals Lacuna Canaliculi Osteon

a) Compact Bone … Osteons … Lamella In Osteon Interstitial lamellae: Circumferential lamellae: Osteon Figure 6.6a

2. Bone Tissue … b) Spongy Bone Trabeculae Function

C. Chemical Composition of Bone Organic Cells Osteoid 2. Inorganic-- Hydroxyapatites Ground Substance Proteoglycans & glycoproteins Collagen Fibers Osteoid = newly secreted Ground & Collagen Inorganic Ca-Phosphate = hydroxyapatites = 65%

III. Bone Formation and Development Introduction Embryo–most Skeleton Tissue: Also some: Ossify, Ossification: Two Methods (Pathways * Intramembraneous– * Endochondral– 2. Baby Childhood  Late Teens Still have Intramembraneous & Endochondral Development *Child: Growth in height at cartilage only 3. Early Adulthood  Old Age Growth in height ends Only *Remodeling

1. Ossification Center appears Mesenchyme cells: Bone Formation and Development … A. Intramembranous Ossification Types of Bones: 1. Ossification Center appears Mesenchyme cells: They differentiate into: Osteoblasts forms an Ossification Center 2. Bone Matrix (Osteoid) is Secreted and then ossifies Osteoblasts secrete osteoid Osteoid calcifies Osteoblasts Osteoblasts are now: Figure 6.7.1

3. Woven Bone and Periosteum Forms Woven Bone: Osteoid laid down randomly around blood vessels = Trabeculae Periosteum forms from vascularized mesenchyme 4. Lamellar Bone Replaces Woven Bone & Red Marrow Appears Trabeculae are replaced w/ lamellar Bone = compact bone plartes Spongy Bone is internal; forms red Marrow Figure 6.7.3

A. Intramembranous Ossification … 4. Mature Bone Formed … At Birth have Fontanels Function: Last Bones to Ossify: Figure 6.7.4

B. Endochondral Ossification Type of Bones Cartilage Model Perichondrium  Periosteum Slide 7 Articular cartilage Secondary ossification center Spongy bone Epiphyseal blood vessel Area of deteriorating cartilage matrix Epiphyseal plate cartilage Hyaline cartilage Spongy bone formation Medullary cavity Bone collar Blood vessel of periosteal bud Primary ossification center 1 2 3 4 5 Childhood to adolescence Week 9 Month 3 Birth Figure 6.8 Endochondral ossification in a long bone. © 2013 Pearson Education, Inc.

Bone Collar Forms Around Cartilage Mode Endochondral Ossification … Bone Collar Forms Around Cartilage Mode Osteoblasts from Periosteum secrete osteoid onto surface of Cartilage = Bone Collar 2. Cartilage in Center of Diaphysis Calcifies and Develops Cavities Chondrocytes Hypertrophy Matrix Calcifies Chondrocytes die Matrix deteriorates forming cavities 3. The Periosteal Bud invades the Internal Cavities & Spongy Bone forms = Primary Ossification Center Periosteal Bud = Nutrient Artery & Vein, Lymphatic Vessel, nerve, osteoblasts & osteoclasts Osteoclasts erode calcified matrix; Osteoblasts secret osteoid on matrix fragments = Early Spongy Bone

4. Diaphysis Elongates & Medullary Cavity forms Osteoclasts degrade Spongy Bone to make Medullary Cavity Secondary Ossification Centers appear in epiphyses via same process as Primary Ossification Centers (Chondrocytes hypertrophy, calcifiy, & die, Matrix deteriorates, Periosteal Bud, Osteoclasts remove matrix & Osteoblasts secrete osteoid) The mostly Cartilage Epiphysis is rapidly growing 2nd Ossification Center grows as adjacent Cartilage is calcified and erodes Birth Epiphyseal blood vessel Medullary cavity

D. Postnatal Growth 5. The Epiphyses Ossify Epiphyses Ossify Cartilage remains only in the epiphyseal plates Cartilage at ends as Articular Cartilage Postnatal Growth D. Postnatal Growth Bone ossification approached the epiphyseal Plates Epiphyseal Plates continues to grow Appositional and Interstitial Growth 3. MICROSCOPIC VIEW– 5 Zones in Long Bone Growth Slide 5 Articular cartilage Spongy bone Epiphyseal plate cartilage Childhood to Adolescence to Adulthood © 2013 Pearson Education, Inc.

D-3 Microscopic View-- 5 Zones in Long Bone Growth a) Resting zone (Reserve) a) Zone of Proliferation (Growth zone) - cartilage cells b) Hypertrophic zone c) Calcification Zone (Zone of Erosion, destruction) - the matrix becomes: d) Ossification Zone (Zone of Bone Formation)

4. Adulthood: Ossification Ends Skeleton: is fully formed D. Postnatal Growth … 4. Adulthood: Ossification Ends Skeleton: is fully formed Cartilage in 2 places Epiphyseal Line: Growth Finished WIDTH GROWTH 5. Growth in Width & Modeling (Remodeling) - Modeling: occurs during a bone’s growth a) Appositional Growth--in diameter: b) Osteoclasts of Endosteum c) Proportions: Shape before Appositional Growth 3. 1. 2.

Figure 6.11 Long bone growth and remodeling during youth. Bone growth--width Bone Modeling Bone growth--Length Articular cartilage Cartilage grows here. Bone replaces cartilage here. Epiphyseal plate 2. Bone that was here has been resorbed. Cartilage grows here. 1. Appositional growth adds bone here. Bone replaces cartilage here. 3. Bone that was here has been resorbed. © 2013 Pearson Education, Inc.

END Continue to PPT #2

Review Question 3. Impact resistance is provided by _________ bone while the mass of a bone is lightened by ____________ bone without jeopardizing strength. Bone, in general, helps to store ___________and fat. Compact …. Spongy …... Minerals

Review Question 4. Bones are covered with a layer of dens connective tissue known as the _____________ and is 65% ______________________. Bone cells include stem cells known as ______________, bone makers called ____________, and bone breakers called ____________. periosteum hydroxyapatites osteogenic cells osteoblasts osteoclasts

Participating… 5. Blood vessels deliver nutrients to bone through long ___________ canals running through the middle of each osteon and sideways _____________ canals. Bone cells trapped inside lacunae receive nourishment via ______________ that radiate from the central canal and __________ fibers provide resistance to stress due to their arrangement within _____________ central perforating canaliculi collagen lamellae

Review Questions 6. Intermembranous ossification forms the clavicles and most _______ bones of the skull. Endochondral ossification occurs when hyaline ___________ is replaced by bone. __________ ossification centers typically become ___________ cavities in long bones, but secondary ossification centers remain what type of bone? flat cartilage Primary medullary spongy Hyaline cartilage Epiphyseal blood vessel plate Medullary cavity Articular Bone collar 1 2 3 4 5

Cartilage Perichondrium: Tissue Functions resists outward expansion forms new chondrocytes, feeds cartilage Three types– REVIEW STUDENTS DO

Growth of Cartilage Not in Mature Cartilage Types: Appositional – from perichondrium Interstitial – inside cartilage Epiphysial Plate:

Bone Structure … Chemical Composition of Bone Organic Cells Ground Substance Proteoglycans & glycoproteins Collagen Fibers Osteoid = newly secreted Ground & Collagen Inorganic Ca-Phosphate = hydroxyapatites = 65%

Figure 6.8 Endochondral ossification in a long bone. Slide 2 Week 9 Hyaline cartilage Bone collar Primary ossification center Bone collar forms around the diaphysis of the hyaline cartilage model. 1 © 2013 Pearson Education, Inc.

Figure 6.8 Endochondral ossification in a long bone. Slide 3 Area of deteriorating cartilage matrix Chondrocytes in shaft Hypertrophy In middle: Cartilage matrix calcifies Chondrocytes die Calcified matrix deteriorates Rest of cartilage alive and mitotic Cartilage in the center of the diaphysis calcifies and then develops cavities. 2 © 2013 Pearson Education, Inc.