Calcium

• Bone is major reserve of calcium• Calcium ions become available for other

tissues– Bone must be destroyed to release the

calcium

• Calcium-too high– Cardiac arrest

• Calcium-too low– Respiratory failure

• Nerve function depends on calcium ions

• Enzymes need it as a cofactor (enzyme connection)

• Blood clotting is aided by calcium

• Bones help “buffer” these calcium levels

AGING AND SKELETON• Bone is continually produced and lost• Sex steroids (hormones) cause more loss

– Menopausal women increase the chance for osteoporosis

– Why not similar loss in men?

• Bone becomes more brittle– Loosing Collagen & hGH

• Bone looses mass– Affects teeth too

Exercise and Bone

• Bone has ability to alter its strength• Stress causes bone to become stronger

– Increases the mineral deposits & collagen

• Lack of exercise causes demineralization– Loss of bone minerals because they are

not being replaced

Mechanical Stress

• Results from pull of skeletal muscles– Problem with bedridden patients– Bones in casts– Athletes have stronger bones!

• Pull of gravity– Astronauts

• Walking/ moderate weight lifting• Epiphyseal plates & adolescents

Repair of Broken Bones

• Fractures– Partial – not fully broken into two pieces – Complete – broken into two or more pieces– Closed (simple) - the bone is broken, but the skin is

intact. – Open (compound) - the bone exits and is visible

through the skin

• Tobacco and nicotine increase the risk of bone fractures

http://www.lancastergeneral.org/content/greystone_36734.htm

Steps in Healing

• Hematoma is formed.– Ruptured vessels cause a blood-filled

swelling.

• Fibrocartilage callus forms.– New capillaries grow.– Phagocytes (WBC) dispose of dead tissue.– Connective tissue forms and closes the

gap.

• Bony callus forms.– Osteogenic cells migrate into the area and

multiply.– The fibrocartilage is replaced with bone.– This is spongy bone.

• Bone is remodeled.– Forms a permanent “patch.”

DISORDERS

• Osteoporosis– Condition of porous bones– Reduction of bone mass– Resorption outpaces deposition– Older females are more prone– Prevention is the best cure

Normal vs Osteoporosis

http://cbs5.com/health/rickets.childhood.disease.2.446155.html

• Rickets– Bone not being calcified– Bone becomes soft and rubbery– Vitamin D deficiency

• Herniated Disc– Ligaments become injured or weakened– Pressure ruptures the fibrocartilage– Material protrudes--herniates

http://rds.yahoo.com/_ylt=A0oGkw7KfBlJQGQAkhNXNyoA;_ylu=X3oDMTB0MzVpYmRuBHNlYwNzYwRjb2xvA3NrMQR2dGlkA0RGUjVfMTI3/SIG=1ibpc5e68/EXP=1226493514/**http%3A//images.search.yahoo.com/images/view%3Fback=http%253A%252F%252Fsearch.yahoo.com%252Fsearch%253Fei%253DUTF-8%2526p%253Dherniated%252Bdisc%252Bpicture%26w=250%26h=196%26imgurl=www.millerandzois.com%252Fimages%252FHerniated%252520Disc.gif%26size=19.9kB%26name=Herniated%2BDisc.gif%26rcurl=http%253A%252F%252Fwww.millerandzois.com%252Fsitemap.xml%26rurl=http%253A%252F%252Fwww.millerandzois.com%252Fsitemap.xml%26p=herniated%2Bdisc%26type=gif%26no=1%26tt=4%252C603%26oid=f8152c390295a8ce%26tit=Herniated%2BDisc.gif%26sigr=118k2q4nr%26sigi=11hc98tlj%26sigb=1208srm2f

• Spina Bifida– Congenital defect (starts at birth)– Vertebral column laminae do not unite– Can cause paralysis– Absence of reflexes– Folic acid prevents this (when mother

takes right from the start)

CONDITIONS

• Bunion– Deformity of big toe– Inflammation, bone spurs, calluses

• Kyphosis– Exaggeration of the thoracic curve of the

vertebral column

• Lordosis– Exaggeration of the lumbar curve in the

vertebral column– Swayback

• Scoliosis– A sideways bending of the vertebral column– School testing

• Osteogenic sarcoma– Bone cancer affecting osteoblasts– Femur, tibia, humerus of teenagers

• Sprain– Tearing or stretching of ligaments

• Strain– Stretching or partial tearing of a muscle

• Rheumatoid arthritis– Autoimmune disease– Attackes cartilage and joint linings– Redness, swelling, pain, loss of function

• Osteoarthritis– Deterioration of articular cartilage– Wear & tear arthritis– Larger joints affected

Rheumatoid Arthritis