CHAPTER 7 CONT…

 Bones consist of:  Bone tissue, cartilage, dense connective tissue, blood, and nervous tissue  Functions of bone: ◦ Points of attachment ◦ Protect and support ◦ House blood producing cells ◦ Store inorganic salts ◦ Form passageways for blood vessels and nerves

 Bones are classified according to their shapes. ◦ Long bone  Long longitudinal axes and expanded ends  Ex. Femur, ulna ◦ Short bone  Cube like, lengths and widths roughly equal  Carpals, tarsals ◦ Flat bone  Plate-like with broad surfaces  Scapula, skull bones

◦ Irregular bone  Variety of shapes, usually connected to other bones  Vertebrae ◦ Sesamoid (round) bone  Small, nodular  patella

 Epiphysis: articulates with other bones  Spongy bone:numerous branching plates  Articular cartilage: hyaline cartilage  Diaphysis: shaft of bone  Medullary cavity: hollow chamber filled with marrow  Endosteum: lines medullary cavity  Periosteum: tough vascular covering that encloses bone  Compact bone: tightly packed tissue in diaphysis

 What are the 5 classifications of bone?

 Bones form by replacing existing connective tissue in either of 2 ways: ◦ 1. Intramembranous bones originate between sheet-like layers of connective tissues. ◦ 2. Endochondral bones begin as masses of cartilage that are later replaced by bone tissue. Osteoblasts: bone forming cells Ossification: formation of bone

 Endochondral Bones ◦ Epiphyseal plate: layers of young cells undergoing mitosis and producing new cells. This plate thickens and the bone lengthens.

 *If the epiphyseal plate is damaged before it ossifies, elongation of the long bone may cease prematurely, or growth may be uneven. For this reason, injuries to the epiphyses of a young person’s bones are of special concern. An epiphysis is sometimes altered surgically in order to equalize the growth rate of bones developing at very different rates.

 A break in a bone  Classified by cause and nature of break  Major steps for fracture repair ◦ 1. blood escapes from ruptured blood vessels and forms a hematoma. ◦ 2. Spongy bone forms in regions close to developing blood vessels, and fibrocartilage forms in more distant regions. ◦ 3. A bony callus replaces fibrocartilage. ◦ 4. Osteoclasts remove excess bony tissue, restoring new bone structure much like the original.

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 What is a break in a bone called?

 Hematopoiesis ◦ Before birth-in the yolk sac ◦ After birth-liver and spleen ◦ Later-bone marrow  Marrow ◦ Soft, netlike mass of connective tissue  Red marrow: forms erythrocytes, leukocytes, thrombocytes  Hemoglobin (carries O2)gives it its red color  Yellow marrow: stores fat  eventually replaces red marrow

 A bones shape makes possible its function. ◦ Processes: bony projections provide sites for ligaments and tendons to attach. ◦ Grooves and openings: provide passageways for blood vessels and nerves.

o Sinus : cavity in bone of skull filled with air in the bones of the face and skull  They lighten the weight of the skull and this is the reason why your head feels heavy and you feel tired and sleepy during a sinus attack.  They give resonance to your voice.  They also filter and moisten the air that we breathe.  They also remove unwanted air particles. o Fontaneles : areas of incomplete Intramembranous ossification. (soft spots) *Know entire chart on page 142!!!!!

 1 st 2 cervical vertebrate are special…they have no body  1.) atlas (nod head) 2.) axis (pivot head)  1 1 Body Lamina Vertebral foramen Spinous process

 Bones and muscles interact as levers.

 Joints (articulations)-the body has 230 ◦ Functional junctions between bones ◦ Classified according to the degree of movement and type of tissue that binds the bone  1. Fibrous  Lie b/w bones in close contact  Ex. Sutures in skull  Most immovable  2. Cartilaginous  Connected by hyaline or fibrocartilage  Ex. Vertebrea, ribs, pubis  Limited movement

 3. Synovial  Most joints are these  Allow for free movement  Some have menisci (shock absorbing pads), others have bursae (fluid filled sacs)  Classified by shape and movement (pg.165) 1. Ball and socket 2. Condyloid 3. Gliding 4. Hinge 5. Pivot 6. saddle

BODY PARTFEMALEMALE SKULLSmaller, lighter, rounder PELVIC GIRDLELighter, thinner PELVIC CAVITY Wider but shorter SACRUMWider COCCYXMore movable

 Bone cancer  Abnormally active osteoclasts destroy bone  Cleft Palate ◦ Fusion of palatine process of the maxilla is incomplete at birth  Spina Bifida  Laminae of vertebrae fails to unite, vertebral arch remains incomplete. Lumbar region is usually affected.  Hip fracture ◦ Usually in elderly people, occurs in neck of femur b/w trochanters

 Ruptured/Herniated Disk ◦ Intervertebral disks are made of tough, outer layer of fibrocartilage and an elastic central mass. Over time. The disk degenerates or ruptures and can press on spinal cord causing back pain and numbness.  Osteoporosis ◦ loss of bone volume and mineral content; spaces fill with fatty tissue; can cause spontaneous fractures; occurs mainly in white females past menopause  Arthritis ◦ Inflamed swollen and painful joints; causes restricted movements; articular cartilage is damaged ◦ Ex. Rhematoid arthritis (severe)