The body’s main axis

 Supports the head  Protects the spinal cord  Site of attachment for limbs and muscles  Consists of a column of 33 irregular bones called vertebrae  Curved when viewed from the side ◦ Differences in structure and size by region  5 anatomical regions

 Cervical (neck) – 7 vertebrae  Thoracic (chest) – 12  Lumbar (lower, “small” of the back) – 5  Sacral (sacrum/upper pelvic) – 5 fused  Coccogeal (tailbone) – 4 fused (vestigial tail)

 2 points of contact called articulations located behind their main body  Articulations with ribs  Spinal cord passes through the hollow cavity between articulations and the main body  Neighboring vertebrae are separated by the intervertebral disc – flat, elastic and compressible shock absorbers ◦ Flat gelatinous center w/tough layer of fibrocartilage ◦ Allows a bit of movement – bend forward, lean back, twist

 Strong impact can compress an intervertebral disc forcing the soft center to balloon outward, press on spinal nerves causing severe pain = herniated or slipped disc  Occurs most often in lumbar vertebrae  Can rupture releasing pulpy contents  Surgery can relieve pain/pressure against the nerve – disc must be fused w/ adjacent vertebrae and limits flexibility

 Severe injury to vertebral column can damage or sever the cord causing partial or complete paralysis of the body below that point  Don’t move someone that might have a spinal injury because it could make it worse

 Stretch your leg in front of you with your heel resting on the floor  Relax your muscles  Try to move your knee cap (patella)  It should be easy to shift it out of position  Now w/out changing position tighten your thigh muscles  The kneecap should be hard to move with thigh contracted  Contraction puts tension on the tendon and ligament and holds patella in place

 Repetitive motions – carpel tunnel syndrome  Connective tissue sheath holds the carpel bones of the wrist together  Carpel tunnel delivers blood vessels, nerves and tendons to the carpel bones  Overuse causes swelling and inflammation of the tendons causing them to press against the nerve supplying the hand  numbness of wrist and hand  Mild cases = pain relievers, severe = surgery to relieve pressure

 Imbalance of the activities of osteoclasts and osteoblasts  Caused by inactivity & poor diet  Hunched posture  Post menopausal women at higher risk due to decreased estrogen

 Stretched or torn ligaments  Accompanied by internal bleeding (bruising), swelling and pain  Ankle most common  Take a long time to heal because ligaments have few cells and poor blood supply  Stretches mend with time  Tears may require surgery to remove damaged tissue and stabilize with a piece of tendon or repositioning other ligaments

 Inflammation of bursae or tendons following injury  Heal slowly due to low blood supply  Caused by blows to joint, tearing injuries, bacterial infection  Treatment – cold first 24 hrs; heat after that, resting, elevating injured area, pain relievers, warming sock treatment  Tennis elbow, knees, shoulder, Achilles tendon (pulls up back of heal)

 General term for joint inflammation  Most common – osteoarthritis – degenerative wear and tear – 20 million Americans >45  Bony spurs form as cartilage wears away and bones thicken  Increased friction causes painful inflammation  OTC meds can help, surgical joint replacement in severe cases; injections of hyaluric acid (a component of hyaline cartilage) can reduce knee pain temporarily

 Also causes joint inflammation but it is caused by the body’s own immune system (autoimmune disorder) which mistakenly attacks the joint tissues