Anatomy & Physiology The Skeletal System: The Framework CH 6

1. Anatomy & PhysiologyThe Skeletal System: The FrameworkCH 6

2. 206 bones • This is the complete framework in the skeletal system

3. Functions of bone • Framework • Provides support

4. Functions of bone • Protects • Underlying organs

5. Functions of bone • Serves as levers • Levers are simple machines • The bones serve as levers, allowing the body to work efficiently

6. Functions of bone • Stores Calcium • To be used to maintain appropriate calcium level • Two Hormones maintain calcium balance Calcium

7. Functions of bone • Produces Red Blood Cells • In the Red bone Marrow • Red blood cell production is controlled by the hormone Erythropoietin

8. SHAPES & SIZES • BONES COME IN MANY SHAPES AND SIZES… • FLAT • IRREGULAR • CUBOIDAL • LONG

10. There are 2 types of osseous tissue in bone… • Compact bone – hard and dense, makes up the main shaft of a long bone and the outer layers of other bones • Spongy bone – this is made up of a meshwork of small, bony plates filled with red marrow and is found at the ends of long bones and at the center of other bones

12. Cartilage • In the womb, the fetus is not made up of bones….it’s cartilage in the 1st month of embryonic life • Bone formation begins the 2nd and 3rd months of embryonic life

13. Ossification • Otherwise known as bone formation

14. Bone Marrow • 2 Types- • Red • Yellow

15. BONE MARROW • Red marrow – found at the ends of the long bones and at the center of other bones. RED MARROW MAUNFACTURES BLOOD CELLS • FYI: in infants & children, all bones contain red marrow. As the body ages, much of the red marrow is transformed into yellow marrow. • In an adult, the main bones that contain red marrow are the chest, spinal column, skull base, upper arm, and thigh

16. Yellow Marrow • Yellow marrow – found in the central cavities of long bones and is composed largely of fat. • If a bone breaks, possibility of yellow marrow coming out and traveling around the blood stream causing an embolism. Pt will immediately become S.O.B./resp. distress

17. Bone Marrow Transplant • Invented in the 1960’s-1970 • Bone marrow transplant (or hematopoietic stem cell transplantation) is a very complicated and risky process, and therefore applied only to patients with life-threatening diseases (who are resistant to chemotherapy).

18. Bone Marrow Transplant

20. BONE GROWTH & REPAIR

21. Don’t be fooled…Bones are living cells • Types • Osteoblasts • Osteocytes • Osteoclasts

22. OSTEOBLASTS: They manufacture intercellular material which is the protein framework that hold calcium deposits.

23. Bone Ingredients Calcium Phosphorus Vitamin D Sun, Dairy Products

24. Osteocytes:Baby bone cells matured and hardened. • Mature osteoblasts that have hardened the intercellular material and calcium surrounding them.

25. Osteoclasts:The Remodelers • Responsible for resorption of bone-Causes reshaping of bone as growth occurs.

27. Bones, Calcium and Hormones • When we look at the relationship of calcium and bone development you have to look at two main hormones related to the maintenance of Calcium Levels in the blood.

28. Parathyroid Hormone Raises the Blood Calcium level Calcitonin Lowers the Blood calcium level

29. Calcitonin – comes from the thyroid gland • Parathyroid hormone (PTH) – released from the parathyroif gland

30. CALCITONIN • Is produced by the thyroid gland and acts directly on osteoclasts • The osteoclasts shrink and stop bone resorption.

31. Resorption • Removal by absorption • In bone resorption, older bone sort of disintegrates and gets reabsorbed, then the new osteoblasts mature into osteocytes becoming stronger, this process takes place during the stage when osteoclasts re-mould the bone • (Boniva and Fosamax)

32. Bone Shapes(Not all information at this site needs to be memorized, but bone shapes, Spongy vs Compact tissue, Bone marrow, periosteum, and endosteum.)

33. Long Bone Epiphysis Contains red bone marrow which produces Red Blood Cells, spongy bone

34. Long Bone Epiphyseal Ring (Growth Plate) This is where bone grows and remodels itself until adolescence when growth will stop.

35. Long Bone Diaphysis Contains Yellow bone marrow which is made of fat.

36. PERIOSTEUM • Membrane that covers the outside of the bone • The inner layer of the periosteum contains osteoblasts that are important in bone formation and also in the repair of fractures • Blood and lymphatic vessels in the periosteum help nourish the bone tissue. Nerves are also in the periosteum “ouch”

38. ENDOSTEUM • A thin membrane that lines the marrow cavity of bone and contains cells that help in the growth and repair of bone tissue • Endo means through or from within

39. Endosteum

40. FORMATION OF A LONG BONE • The changing of cartilage to hard bone begins at the center of the shaft • At a later time, other bone forming centers develop across the ends of the bones • The long bones cont. to grow in length at these centers from childhood – late teens

41. FORMATION OF A LONG BONE CONT’D… • Each bone forming region hardens • As a bone grows in length, the shaft is remodeled so it grows wider and the central marrow cavity increases in size • This process conts. throughout life, more actively in some parts of the bone than in others due to wear and tear or injuries

42. SOFT BONES • Children have softer bones than do adults due to the cartilage and bone still being in the “growing process”

43. ELDERLY BONES • The cont’d growth and reformation of bones throughout life starts to slow down and the elderly person’s bones are weaker and more fragile • Elderly have a decreased ability to form the protein framework on which ca+ salts are deposited - injury occurs

44. Head – rounded knob-like end, separated from the rest of the bone by a slender region called the neck, like on the femur bone BONE MARKINGS

45. Process – a large projection of a bone such as in the upper part of the ulna in the forearm that creates the elbow

46. Crest - a distinct border or ridge often rough such as in over the top of the hip bone BONE MARKINGS

47. Spine - a sharp projection from the surface of a bone such as in the spine of the scapula or shoulder bone

48. Foramen - a hole that allows a nerve or blood vessel to pass through or between bones Depressions or holes in bones

49. Sinus – an air space found in some bones

50. Fossa – a depression on a bone surface