Bone Tissue Chapter 7. Objectives Know the functions of the skeletal system Understand how bones are...
-
Upload
loreen-cobb -
Category
Documents
-
view
212 -
download
0
Transcript of Bone Tissue Chapter 7. Objectives Know the functions of the skeletal system Understand how bones are...
![Page 1: Bone Tissue Chapter 7. Objectives Know the functions of the skeletal system Understand how bones are classified Identify the macroscopic and microscopic.](https://reader036.fdocuments.in/reader036/viewer/2022070413/5697bfbe1a28abf838ca2d25/html5/thumbnails/1.jpg)
Bone Tissue
Chapter 7
![Page 2: Bone Tissue Chapter 7. Objectives Know the functions of the skeletal system Understand how bones are classified Identify the macroscopic and microscopic.](https://reader036.fdocuments.in/reader036/viewer/2022070413/5697bfbe1a28abf838ca2d25/html5/thumbnails/2.jpg)
Objectives• Know the functions of the skeletal system
• Understand how bones are classified
• Identify the macroscopic and microscopic features of bone
• Understand how bone is developed and physiologically controlled
• Know what a fracture is and how it is repaired
• Know some bone disorders
![Page 3: Bone Tissue Chapter 7. Objectives Know the functions of the skeletal system Understand how bones are classified Identify the macroscopic and microscopic.](https://reader036.fdocuments.in/reader036/viewer/2022070413/5697bfbe1a28abf838ca2d25/html5/thumbnails/3.jpg)
Skeletal System• Composed of bones, cartilages, and ligaments joined tightly
together to form a strong, flexible framework for the body
• Skeleton functions– Support – Protection– Movement – Electrolyte balance – Acid-base balance– Blood formation
• Osseous tissue– Connective tissue with a hardened matrix
• Deposition of calcium phosphate and other minerals– Part of the composition of a bone
http://www.amersol.edu.pe/class09/_09pdelaf/7th/science/webpages/skeleton.html
![Page 4: Bone Tissue Chapter 7. Objectives Know the functions of the skeletal system Understand how bones are classified Identify the macroscopic and microscopic.](https://reader036.fdocuments.in/reader036/viewer/2022070413/5697bfbe1a28abf838ca2d25/html5/thumbnails/4.jpg)
Classification of Bones
• Classified based on shape and corresponding function
• Four categories– Long bones– Short bones– Irregular bones– Flat bones
massasoit-bio.net
![Page 5: Bone Tissue Chapter 7. Objectives Know the functions of the skeletal system Understand how bones are classified Identify the macroscopic and microscopic.](https://reader036.fdocuments.in/reader036/viewer/2022070413/5697bfbe1a28abf838ca2d25/html5/thumbnails/5.jpg)
General Features of Bones • Epiphysis
– Ends of the bone– Composed of cancellous (spongy) bone
• Diaphysis– Shaft of the bone– Composed of compact bone
• Medullary cavity– Contains yellow bone marrow
– Epiphyiseal plate
http://pathologyoutlines.com/bone.html
![Page 6: Bone Tissue Chapter 7. Objectives Know the functions of the skeletal system Understand how bones are classified Identify the macroscopic and microscopic.](https://reader036.fdocuments.in/reader036/viewer/2022070413/5697bfbe1a28abf838ca2d25/html5/thumbnails/6.jpg)
Structure of Bone
Figure 5.1
![Page 7: Bone Tissue Chapter 7. Objectives Know the functions of the skeletal system Understand how bones are classified Identify the macroscopic and microscopic.](https://reader036.fdocuments.in/reader036/viewer/2022070413/5697bfbe1a28abf838ca2d25/html5/thumbnails/7.jpg)
Histology• Four main types of bone cells
– Osteogenic (osteoprogenitor) cells• give rise to osteoblasts , osteocytes
– Osteoblasts• Bone-forming cells• Found along endosteum and
periosteum• Secrete osteocalcin
– Osteocytes• Former osteoblasts that have been
trapped in their lacunae• Maintain bony matrix• Strain sensors
– Octeoclasts• Bone-dissolving cells
• Matrix– composed of inorganic and
organic components
• Inorganic component– Hydroxyapaptite
• Composed mainly of CaPO4 salt
• Organic components – Protein and carbohydrate
• Collagen
• Bone is a composite
![Page 8: Bone Tissue Chapter 7. Objectives Know the functions of the skeletal system Understand how bones are classified Identify the macroscopic and microscopic.](https://reader036.fdocuments.in/reader036/viewer/2022070413/5697bfbe1a28abf838ca2d25/html5/thumbnails/8.jpg)
Compact Bone• Osteon (haversian system)
– Basic structural unit of compact bone
• Central (haversian) canal surrounded by concentric lamellae (matrix)
• Perforating canals– Transverse or diagonal passages
into the central canal– Originate at nutrient foramen
ask.com
![Page 9: Bone Tissue Chapter 7. Objectives Know the functions of the skeletal system Understand how bones are classified Identify the macroscopic and microscopic.](https://reader036.fdocuments.in/reader036/viewer/2022070413/5697bfbe1a28abf838ca2d25/html5/thumbnails/9.jpg)
Spongy Bone
• Composed by a network of spicules and trabeculae
• Spaces filled with red marrow
• Beams arranged to sustain stress
commons.wikimedia.org
![Page 10: Bone Tissue Chapter 7. Objectives Know the functions of the skeletal system Understand how bones are classified Identify the macroscopic and microscopic.](https://reader036.fdocuments.in/reader036/viewer/2022070413/5697bfbe1a28abf838ca2d25/html5/thumbnails/10.jpg)
Bone Development
• Ossification or osteogenesis– Formation of bone
• Two methods– Intramembranous ossification
– Endochondral ossification
![Page 11: Bone Tissue Chapter 7. Objectives Know the functions of the skeletal system Understand how bones are classified Identify the macroscopic and microscopic.](https://reader036.fdocuments.in/reader036/viewer/2022070413/5697bfbe1a28abf838ca2d25/html5/thumbnails/11.jpg)
Intramembranous Ossification
• Produces flat bones of skull and clavicles
• Starts with osteoid
• End with diploe
massasoit-bio.net
![Page 12: Bone Tissue Chapter 7. Objectives Know the functions of the skeletal system Understand how bones are classified Identify the macroscopic and microscopic.](https://reader036.fdocuments.in/reader036/viewer/2022070413/5697bfbe1a28abf838ca2d25/html5/thumbnails/12.jpg)
Endochondral Ossification• Bone develops from a hyaline model
trjohn.blogspot.com
![Page 13: Bone Tissue Chapter 7. Objectives Know the functions of the skeletal system Understand how bones are classified Identify the macroscopic and microscopic.](https://reader036.fdocuments.in/reader036/viewer/2022070413/5697bfbe1a28abf838ca2d25/html5/thumbnails/13.jpg)
Bone Growth and Remodeling
• Bone Elongation– Involves epiphyseal plates
• Hyaline cartilage between to transitional zones (metaphysis)
• Zones of mataphysis– Reserve cartilage– Cell proliferation– Cell hypertrophy– Calcification– Bone deposition
• Spongy bonenzdl.org
![Page 14: Bone Tissue Chapter 7. Objectives Know the functions of the skeletal system Understand how bones are classified Identify the macroscopic and microscopic.](https://reader036.fdocuments.in/reader036/viewer/2022070413/5697bfbe1a28abf838ca2d25/html5/thumbnails/14.jpg)
Bone Growth and Remodeling• Interstitial growth
– Result from growth of cartilage within the metaphysis– Finite process
• Epiphyseal line
• Appositional growth– Growth in diameter and thickness
• Circumferential lamellae
• Remodeling– Wolff’s law of bone
• The architecture of bone is determined by the mechanical stresses placed up it.
– Bone adapts to withstand stress
![Page 15: Bone Tissue Chapter 7. Objectives Know the functions of the skeletal system Understand how bones are classified Identify the macroscopic and microscopic.](https://reader036.fdocuments.in/reader036/viewer/2022070413/5697bfbe1a28abf838ca2d25/html5/thumbnails/15.jpg)
Physiology of Osseous Tissue• Mineral deposition
– Calcium and phosphate are allowed to reach their solubility product
• Precipitate in the matrix– Ectopic ossification
• Abnormal calcification of soft tissue– Calculus
• Mineral resorption– HCl secreted by osteoclasts– Acid phosphatase
• Absorbs collagen
![Page 16: Bone Tissue Chapter 7. Objectives Know the functions of the skeletal system Understand how bones are classified Identify the macroscopic and microscopic.](https://reader036.fdocuments.in/reader036/viewer/2022070413/5697bfbe1a28abf838ca2d25/html5/thumbnails/16.jpg)
Calcium Homeostasis
• Hypocalcemia– Leads to excitability of nervous system
• Hypercalcimia– Leads to depression of nervous system
![Page 17: Bone Tissue Chapter 7. Objectives Know the functions of the skeletal system Understand how bones are classified Identify the macroscopic and microscopic.](https://reader036.fdocuments.in/reader036/viewer/2022070413/5697bfbe1a28abf838ca2d25/html5/thumbnails/17.jpg)
Calcium Homeostasis• Regulated by three hormones
– Calcitonin• Secreted by parafollicular cells in thyroid• Promote deposition of calcium in the bone• Decreases calcium level in blood
– Inhibit osteoclasts, promote osteoblast activity– Parathyroid hormone
• Secreted by parathyroid glands• Promotes bone resorption• Increases calcium level in blood
– Raise osteoclast population– Promotes calcium reabsorption in kidneys– Promotes calcitriol synthesis– Inhibits collagen deposition
– Calcitriol• Increases calcium level in blood
– Promotes more calcium absorption by intestine– Promotes reapsorption from skeleton
![Page 18: Bone Tissue Chapter 7. Objectives Know the functions of the skeletal system Understand how bones are classified Identify the macroscopic and microscopic.](https://reader036.fdocuments.in/reader036/viewer/2022070413/5697bfbe1a28abf838ca2d25/html5/thumbnails/18.jpg)
Fractures and Repair
• Fracture– Break in the bone– Two types
• Stress• Pathological• Table 7-2 for classifications
• Granulation tisssue– Fibrous mass of
capillaries and cells within hematoma
medical-definitions.com
![Page 19: Bone Tissue Chapter 7. Objectives Know the functions of the skeletal system Understand how bones are classified Identify the macroscopic and microscopic.](https://reader036.fdocuments.in/reader036/viewer/2022070413/5697bfbe1a28abf838ca2d25/html5/thumbnails/19.jpg)
Bone Disorders• Osteoporosis
– Sever loss of bone density • Osteoclast more active than osteoblasts
• Osteosarcoma– Most common and deadly form of bone cancer
• Metastasizes quickly
• Osteogenesis imperfecta– Brittle bones
• Defect in collagen deposition