1. Honors Anatomy & Physiology

2. A. Supporting connective tissue 1. Matrix- Contains numerous fibers & in some cases, insoluble salts B. Cartilage – Support, framework, model for developing bone 1. Chondrocytes – cartilage cell 2. Matrix- firm gel containing chondroitin sulfates 3. Hyaline cartilage a) Flexible- closely packed collagen fibers b) Location (1) Ends of bones involved in movable joints (2) Connections between ribs and sternum

4. 4. Elastic cartilage a) Elastic fibers- Dense network; more flexible than hyaline cartilage b) Location – outer ear, tip of nose

5. 5.Fibrocartilage a) Collagen fibers- Very high concentration; shock absorbtion b) Location- Intervertebral discs, between knees, pelvic girdle

7. 6. Lacks direct blood supply a) Slow to heal b) Blood supply comes from connective tissue covering → perichondrium

8. C.Bone 1. Osteocyte – bone cell 2. Matrix – Collagen fibers plus calcium salts

9. A. 206 bones of the skeleton can be grouped into two divisions 1. Axial Skeleton a) Skull b) Vertebral column c) Thorax 2. Appendicular Skeleton a) Appendages b) Structures by which appendages are attached to the axial skeleton

10. III. Functions of the Skeletal System A. Support – framework for the body B. Protection – protection for soft tissues and organs C. Movement - attachment for skeletal muscles D. Hematopoiesis – blood cell production E. Storage of minerals (calcium & phosphorous) and lipids

11. IV. Macroscopic Structures of the Bone A. Types of bones 1. Long bones – longer than they are wide e.g. femur 2. Short bone – roughly cube-shaped e.g. carpal, tarsal 3. Flat bones – thin, flat & often curved e.g. sternum, ribs, skull 4. Irregular bones – odd shapes e.g. os coxa, scapula, vertebrae

12. B. Structure of a typical long bone 1. Diaphysis – the shaft or body 2. Epiphysis – the end 3. Metaphysis – the junction of diaphysis and epiphysis 4. Medullary cavity – area within the diaphysis 5. Periosteum – connective tissue on the outer portion; contains blood vessels 6. Endosteum - connective tissue lining the medullary cavity 7. Articular cartilage – hyaline cartilage on the ends of the epiphysis

14. A. Osteoblasts: Bone building, bone repairing cells in the periosteum B. Osteocytes: Mature bone cells within the bone matrix (lacunae) C.Osteoclasts: Bone destroying cells – causes reabsorption of bone

15. A. Compact Bone 1. Location and distribution – 80% of total bone mass a) On the outer surface of all bones – smooth, white appearance b) Makes up most of the diaphysis of long bones

17. 2. Structure a) Very dense, stress-bearing b) Haversian System = Osteon (1) Haversian canal (osteonic canal) – carries nutrients and wastes to and from the osteocytes (2) Lamellae: concentric cylinder –shaped calcified structure (3) Lacunae – small spaces containing osteocyte (4) Osteocyte – Bone cell that facilitates exchange of calcium between blood and bone

18. (5) Canaliculi – canals connecting the lacunae together and to the Haversian canal

20. Haversian System (Osteon)

21. c) Nutrient foramen – opening in bone that allows passage of blood vessels and nerves d) Matrix – calcium and phosphorous salts e) Yellow marrow – Medullary cavity of long bones - fat storage

22. B. Cancellous Bone – Spongy Bone 1. Location and distribution a) The inner surface of all flat, irregular, and short bones b) The epiphysis of long bones 2. Structure - Trabeculae a) Porous – No Haversian systems b) Contains blood vessels c) Red marrow – contains blood- forming cells

23. A. Endochondral Ossification: Long Bone Growth 1. Embryo at 6-8 weeks has hyaline cartilage skeleton – mostly appendicular skeleton 2. At 8-12 weeks blood vessel invades perichondrium a) Changes nutrition of chondrocytes (cartilage is avascular!) b) Chondrocytes respecialize into osteoblasts 3. Osteoblasts lay down layer of compact bone around diaphysis = bone collar

24. 4. Chondrocytes starve, die and hypertrophy (swell up) a) Release alkaline phosphatase b) Causes Ca 2+ salts to be deposited and form a weak spongy bone 5. Blood vessels, nerves, osteoblasts, osteoclasts and red bone marrow invade the bone and move to center of diaphysis a) Known as Periosteal Bud b) Sets up the Primary Ossification Center (POC)

25. 6. Primary Ossification Center (POC) sets up “shop” a) Osteoclasts begin to eat weak spongy bone from dead cartilage, forming the medullary cavity b) Ossification center begins to move towards the epiphysis – “The Chase” 7. Bone grows in length as POC chases growing cartilage

26. 8. Secondary Ossification Centers (SOC) begin to form at the epiphysis (around birth) a) Different from POC in that osteoclasts do not eat spongy bone – instead, weak spongy bone is remodeled and strengthened b) Grows toward diaphysis TRAPPING the cartilage c) Known as epiphyseal growth plate 9. Growth hormone from pituitary gland stimulates this band of cartilage to become mitotic – results in bone growth (Length)

28. 10. Sex hormones can also influence rapid growth – ie. Growth spurts during puberty 11. When growth hormone levels fall – POC meets SOC and they form the epiphyseal line – growth in length is over

29. 12. Growth in Diameter of Long Bone a) Endosteum contains packets of osteoclasts b) Periosteum contains packets of osteoblasts c) Stress on Bones (1) Pull of muscles and amount of weight carried puts stress on bones (2) Areas of bone that receives more stress stimulates osteoblasts to lay down more bone (3) Stress determines WHERE the bone will remodel

30. d) Calcium levels of the blood (1) Must be between 9 -11 mg/100mL of blood for proper nervous and muscle tissue function (2) Calcitonin (thyroid) lowers blood calcium levels by stimulating osteoblasts to build bone (3) Parathyroid Hormone (PTH) raises blood calcium levels by stimulating osteoclasts to remove calcium salts from bone matrix and place it into blood

31. (4) Hormones determine WHEN the bone remodels PTHCALCITONIN Osteoclasts Osteoblasts ↑ Ca 2+ Levels ↓ Ca 2+ Levels in blood in blood Ca 2+ Levels 9-11 mg/100 mL blood

32. B. Intramembranous Ossification 1. Flat bones (skull) and some irregular bones 2. Cells within the middle of the tissue respecialize into osteoblasts and cluster together 3. Osteoblasts secrete bony matrix around the collagen fibers and form ossification center- -Trabeculae are formed. 4. Periosteum forms on the outside of the fibrous membrane and produces compact bone 5. Ossification center moves outward in all directions until the cartilage is completely ossified

34. A. Fracture Type 1. Simple fracture – no damage to other tissue 2. Compound fracture – break in the skin 3. Comminuted fracture – number of parts 4. Impact fracture – driven into each other 5. Spiral fracture – twisted apart (torque) 6. Greenstick fracture – partial break (young bone)

36. B. Healing of Fractures 1. Realignment of bones – Reduction a) Open Reduction – surgery required to realign bones (screws, plates, or rods may be needed) b) Closed Reduction – No surgery needed 2. Hematoma forms around the broken ends of bone

37. 3. Fibrocartilage callus formation a) Break bridged with fibrocartilage b) Stabilizes broken ends and sets up ossification 4. Ossification a)Cartilage converted into bone 5. Healing time depends on fracture type, age of patient 6. Remodeling a) Denser matrix of bone kept where break occurs b) Gives extra strength to this area

39. A. Function 1. Muscle and ligament attachment 2. Form joints

40. Every bump, groove, and hole has a name on your bones

41.  Two types of bone markings:  Projections (aka processes) that grow out from the bone  Depressions (cavities) that indent the bone

42.  1) Condyle: Rounded articular projection Condyle

43.  2) Head: bony expansion on a narrow neck  3) Facet: smooth, nearly flat articular surface

44.  4) Ramus: Armlike bar of bone

45. 1) Crest: Narrow ridge of bone (Line: smaller than a crest) 2) Epicondyle: Raised area on or above a condyle ULNA

46. 3) Tubercle: Small rounded projection 4) Tuberosity: large rounded or roughened projection 5) Trochanter: very large, blunt projection (only on femur) Proximal Tibia

47. 6) Spine: Sharp, pointed projection Thoracic Vertebrae

48.  Allow blood vessels or nerves to pass through. 1) Meatus: (me - A- tus) Canal or tube

49. 2) Fossa: shallow basin 3) Fissure: narrow, slit- like opening

50. 4) Sinus: Cavity within a bone; filled with air and lined with mucous membranes 5) Foramen: Round or oval opening Foramen Magnum

51. 6) Sulcus, Groove or Furrow: a shallow depression

52. Projections 1) Condyle 2) Head 3) Facet 4) Ramus 5) Crest 6) Epicondyle 7) Tubercle 8) Tuberosity 9) Trochanter 10) Spine Depressions 1) Meatus 2) Fossa 3) Fissure 4) Sinus 5) Sulcus or Groove or Furrow