Notes

Bone Function A.Examples of Support and Protection 1.Bones give shape to the head, thorax, and limbs. 2.Bones such as the pelvis and lower limbs provide support for the body. 3.Bones of the skull protect the brain,ears, and eyes. Copyright  The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

B.Body Movement 1.Bones can act as levers (mechanical device). a.A lever has four components: a rigid bar, a pivot or fulcrum, an object that is moved against resistance, and a force that supplies energy. b. Rigid rod-forearm; elbow is fulcrum; hand is the object of resistance; force is supplied by biceps MOVE HAND UP Copyright  The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Hematopoiesis Blood cell formation Begins in the yolk sac of the human embryo; later they are made in the liver and spleen; eventually form in bone marrow Hemoglobin-red oxygen carrying pigment

C.Blood Cell Formation 1. Two kinds of marrow occupy the medullary cavities of bone. a.Red marrow functions in the formation of red blood cells, white blood cells, and platelets, and is found in the spongy bone of the skull, ribs, sternum, clavicles, vertebrae, and pelvis.(mostly in infants-later turns into yellow) b.Yellow marrow, occupying the cavities of most bones, stores fat. Copyright  The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Bone Marrow Transplant Removed from spongy bone of donor or umbilical cord of new born (these are stem cells) Donor selected –molecule pattern on red blood cells must be close to recipient Cells are injected into the bloodstream (marrow has been destroyed by chemo or radiation); cells travel to the spaces where there is no marrow.

Graft-versus-host-disease-immune system rejects transplant and attacks recipient Treats disorders like leukemia and sickle cell disease Cells they are using are stem cells.

D.Storage of Inorganic Salts 1. Calcium is important for metabolism. 2.when blood levels are low, osteoclasts release calcium from bone and break bone down. 3. High calcium causes osteoblasts to form bone tissue. Copyright  The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

4.Bone also stores magnesium, sodium, potassium, and carbonate ions. 5.Bones can also accumulate harmful elements, such as lead, radium, and strontium. Copyright  The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Skeletal Organization A.The axial skeleton consists of the skull, thorax, and vertebrae. B.The appendicular skeleton consists of the bones that make up arms and legs. Copyright  The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Osteoporosis Loss of bone tissue These bones fill with fibrous and fatty tissue and are easy to break. They can no longer take the weight. Bone mass peaks 35. No drinking, smoking, take calcium supplements, exercise

Pg 131 Fracture and hematoma Fracture-break in the bone Hematoma-break with a blood clot Phagocytic cells clean up blood clot and osteoclasts clean up bone Doctors immobilize bone; use rods, wires, and nails to align the bone