THE MAKING OF A BONE

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(1)THE MAKING OF A BONE.

(2) Bone Cells 1. Osteoprogenitor cells- stem cells of bone. • • • •. Spindle shaped Oval nucleus Pale cytoplasm Found in the covering of the bone, and lining of inner cavity of bone.. • Osteoprogenitor cells differentiate into osteoblasts..

(3) 2. Osteoblasts- make the extracellular matrix .. • Cells are more columnar • have well developed Golgi bodies. – Osteoblasts differentiate into osteocytes..

(4) 3. Osteocytes: maintain the matrix; mature bone cell. • Note how osteocytes are connected to each other. • They live in small spaces in the matrix called lacunae..

(5) 4.. Osteoclasts-. -secrete acid that breaks down mineralized matrix • Multinucleated • Large After bone is broken down, what cell will invade the area and deposit new bone tissue? Osteoblast.

(6) Bone Tissue Compact bone Found in the shafts of our long bones and on the inner and outer surface of our flat bones. Provide strength. Osteon- cylinder shaped unit Central/Haversion canalcontains blood vessels. 1. 2. Canaliculi- small tubes in the matirx that connect bone cells. 3 4. Lacuna- Cavity that holds an osteocyte Lamellae- layers of matrix.

(7) Spongy (cancellous) bone. • Found within flat bones and in the ends of long bones. • Stores red bone marrow. How do you think compact and spongy bone got their names?.

(8) Cartilage • Hyaline cartilage -found at ends of long bones between joints -important in bone growth, protects ends of bones. • Fibrocartilage -found between vertebrae -cushions.

(9) Dense Connective tissue (regular) • Covering of a bone • Allows for attachment of tendons and ligaments.

(10) Blood • Found throughout the bone • Brings nutrients, removes wastes.

(11) -Nervous tissue • Found in the covering of the bone • Sends and receives messages.

(12) Together these tissues function in... 1. Support and Movement (Explain) – Our bones provide support for sitting and standing. – Our bones act as levers for our muscles to pull against.. 2. Protection (Explain) – Our skulls protect our brain. – Our vertebrae protects our spinal cord. – Our ribcage acts as a shield to protect our important thoracic organs (heart and lungs)..

(13) 3. Storage (What is bone storing?) – Our skeletal tissue stores minerals that can be released as needed- calcium and phosphorous – Adult long bones store yellow marrow, an energy reserve. 4. Hematopoiesis (Hemopoiesis) -formation of blood cells.

(14) Types of bones 1. •. •. Flat bones Have broad flat surfaces (often compared to a plate of armor) Protect major internal organs.

(15) Types of bones 2. •. •. Long Bones Longer than wide, growth plates at either end Serve as rigid levers that are acted upon by skeletal muscle to produce movements.

(16) Types of Bones 3. •. •. Short bones Block-like; length, width and height are almost equal Glide past one another enabling the ankles and wrists to move in multiple directions. Scaphoid- wrist bone.

(17) Types of Bones 4. •. •. Irregular Bones Variety of shapes, many projections, don’t fit into other categories Projections allow for muscle attachments, shapes allow for limited motion and protection.

(18) Types of bones 5. Sesamoid bone -small bones embedded within tendons and adjacent to joints -protect the tendon and improve its mechanical advantage.

(19) Lab: Types of Bones Success in Lab: 1.Find a picture of the bone (purple star ) in your book, determine its name and type. 2.Do not move to the next lab station until it is open. 3.Do not experience "lab rage". 4. Always move in a counterclockwise direction..

(20) Naming the parts of a long bone..

(21) The membranes of bone. • Bones are protected by a membrane of dense regular connective tissue. – The superficial surface is covered with the periosteum. – The surface of the medullary cavity is covered with the endosteum..

(22) Osteogenesis: Formation of Your Bones • During embryogenesis our bones are formed of other tissue. – Long bones are initially formed of cartilage in a process called endochondrial ossification. – Flat bones are initially formed of connective tissue membranes in a process called intramembranous ossification. – The cartilage or membranes are ultimately replaced with bone tissue. Word bank: bone, endochondrial, intramembranous.

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(25) Intramembranous bone.

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(27) Growth: Enlarging Your Bones • Lengthwise growth of long bones occurs in cartilage structures called epiphyseal plates. – Epiphyseal plates are four-layered structures found between the epiphysis and diaphysis of long bones. – Epiphyseal plates are converted to bone following puberty, ending our ability to increase in height. Word bank: diaphysis, epiphyseal plates, epiphysis, puberty.

(28) Label these 3 sections of the bone:. Name each bone: 4) the top one? 5) Big bottom bone? 6) Smaller bottom bone?.

(29) Lengthwise growth of Long Bones. Figure 6.8.

(30) Increasing Bone Diameter. • As your bones lengthen, they must also increase in diameter. – They do this be increasing osteoblast activity in the periosteum.. • They must also increase the diameter of their medullary cavity. – They do this by increasing osteoclast activity in the endosteum. Word Bank: …blast, …clast, …cyte, ….progenitor.

(31) Remodeling: Keeping Your Bones New. • Throughout life, we remodel bones to keep them new. • Osteoclasts resorb bone matrix to make room for new matrix. • Osteoprogenitor cells produce new osteoblasts • Osteoblasts produce new bone matrix. Word bank: Osteoprogenitor, Osteoblast, Osteocyte, Osteoclasts.

(32) Remodeling Figure 6.10. Figure 6.9.

(33) Bone Disease: Osteoporosis Compare normal bone and osteoporosis. Collagen framework and deposited minerals are broken down faster than they are formed normally. What happens to the strength of the bone during osteoporosis? The canals that connect the osteocytes become wider weakening the bone.

(34) Bone Disease: Sarcoma • Bone cancer • Osteosarcoma is the most common and occurs in long bones • Chondrosarcoma occurs mainly in the pelvis, ribs and sternum.

(35) Osteochondroma • What’s wrong with Curtis? • Non-cancer ous bone growth.

(36) Non-cancerous bone tumor • After removal of a tumor on the femur, a 7 inch incision was made to insert stabilizing hardware..

(37) Bone Disease: Osteomyelitis • Infection of a bone, usually by bacteria. • Watch Amazing Medical Stories.

(38) Bone disease: Osteomalacia • A loss of calcium and phosphorus, often as the result of vitamin D deficiency, can cause weak bones • Known as rickets • What do you notice in the X-ray?.

(39) Bone Fractures • Depends on the direction and degree of force. • Types -Simple- bone remains beneath the skin -Compound- bone projects above skin.

(40) What type is this?.

(41) Angular to bone axis. Partial Crushed. Right angle to bone axis. Twiste d.

(42) What’s wrong with Mitch. Transverse fracture.

(43) Ryan Regeth • What’s wrong? • Broken clavicle at the acromion process.

(44) Zach Janczak • What’s wrong? • 4th metacarpal.

(45) Ms. Cerletty • What’s wrong? • Patellar ACL autograft, screw protruding from tibia after 22 years.

(46) Michael Mathwick. Before surgery. After surgery.

(47) What’s wrong? Note the bloody area on the bone. This is where a piece of the femur is missing..

(48) Allograft from a cadaver.

(49) Repaired bone.

(50) Bone Repair A.. Soft, spongy bone is deposited on the callus, blood vessels heal and grow across the break. B.. New compact bone replaces the callus, completing the repair. • 1 hour • Several days • 1-2 weeks • 2-3 months. C. Blood leaking from the site of injury rapidly forms a clot D. Fibroblasts form a callus. The callus gradually bridges the gap between the broken bone ends, replacing the clot.

(51) Bone Repair.

(52) Bone Terminology Terms used to describe bone structures Depressions: Low area or indentation • Coronoid fossaelbow joint Fossa: A relatively deep pit or depression.

(53) Cavity: a hole or opening Obturator foramen Foramen: An opening through a bonepassageway for blood vessels and nerves.

(54) Joint: where 2 bones meet. Sutures.

(55) Process: A projection Greater tubercle Lesser tubercle •a small knob-like process Deltoid tuberosity •knob-like process larger than a tubercle.

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