1. Skeletal System CHAPTER 6

2. 2 Skeletal System Human skeleton consists of 206 bones –Serves as supporting framework of body –Protects vital internal organs –Important role in movement = attachments for muscles –Reservoir for storing minerals –Red bone marrow = blood cell formation

3. 3 Bone Structure Diaphysis –Main shaft-like portion of a long bone –Compact bone Epiphysis –Located at each end of a long bone Epiphyseal line –Separates diaphysis from epiphysis

4. 4 Bone Structure Periosteum –Covers the surface of the long bone Articular cartilage –Covers joint surfaces Medullary (marrow) cavity –Contains yellow marrow

5. 5 Bone Structure Spongy bone (trabeculae) –Also called cancellous bone Red bone marrow –Site for blood cell production Yellow marrow –Stores fat

6. 6 Bone Structure

7. 7 Bone Markings Bone markings = specific features of bones –Enlargements that extend out from the bone –Openings within the bone –Hollow regions within the bone –Points of attachment for muscles and tendons –Points for joining one bone to another –Cavities and passage for nerves and blood vessels

8. 8 Concave areas or openings in a bone –Help form joints –Serve as points of attachment for muscle Sulcus –Groove or depression in a bone Example = fissure Sinus –Opening or hollow space in a bone Example = frontal sinus Bone Depressions

9. 9 Fossa –Hollow or shallow concave depression in bone Example = fossa of the iliac (hip) bone Foramen –Hole within a bone for blood vessels or nerves to pass through Example = Foramen magnum of the skull Bone Depressions

10. 10 Cranial Bones Cranium = bony skull –Envelops brain Composed of eight bones –Immovable bones Borders meet to form immovable joints –Immovable joints = sutures

11. 11 Cranial Bones

12. 12 Facial Bones Two bones provide distinctive shape to face –Maxillae (upper jaw bones) –Mandible (lower jaw bone) All facial bones connected by immovable joints (sutures) –One exception (mandible)

13. 13 Facial Bones

14. 14 Vertebral Bones Form long axis of the body –Referred to as spinal column or backbone –24 vertebrae + sacrum + coccyx –Offer protection to spinal cord

15. 15 Cervical vertebrae –Vertebrae of the neck (cervic/o = neck) –Identified as C 1 – C 7 Thoracic vertebrae –Vertebrae of the chest (thorac/o = chest) –Identified as T 1 – T 12 Lumbar vertebrae –Vertebrae of lower back (lumb/o = lower back, loins) –Identified as L 1 -L 5 Vertebral Bones

16. 16 Vertebral Bones Sacrum –Singular, triangular shaped bone –Resulted from fusion of five individual sacral bones in the child Coccyx –Also called “tailbone” –Resulted from fusion of four individual coccygeal bones in the child

17. 17 True ribs (Ribs 1-7) –Attach to sternum in front and vertebrae in back False ribs (Ribs 8-10) –Attach to vertebrae in back but attach to cartilage of 7 th rib in front – not the sternum Floating ribs (Ribs 11-12) –Attach to vertebrae in back –Completely free of attachment in front Bones of the Thorax

18. 18 Bones of the Upper Extremities

19. 19 Pelvic Bones

20. 20 Femur –Thigh bone Patella –Knee bone or kneecap Tibia –Larger and stronger of the two lower leg bones Fibula –More slender of the two lower leg bones Bones of the Lower Extremities

21. 21 Ankle bones (Tarsals) –Calcaneus –Talus bone Foot bones –Metatarsals –Phalanges Bones of the Ankle and Foot

22. PATHOLOGICAL CONDITIONS Skeletal System

23. 23 Osteomalacia Pronounced –(oss-tee-oh-mah-LAY-she-ah) Defined –Abnormal softening of the bones due to a deficiency of calcium and phosphorus in the blood Which is necessary for bone mineralization

24. 24 Osteomyelitis Pronounced –(oss-tee-oh-my-ell-EYE-tis) Defined –A local or generalized infection of the bone and bone marrow –Resulting from a bacterial infection that has spread to the bone tissue through the blood

25. 25 Osteoporosis Pronounced –(oss-tee-oh-poh-ROW-sis) Defined –Porous bones –Bones that were once strong become fragile due to loss of bone density

26. 26 Osteoporosis

27. 27 Ewing’s Sarcoma Pronounced –(YOO-wings sar-KOH-mah) Defined –Malignant tumor of the bones common to young adults, particularly adolescent boys

28. 28 Osteogenic Sarcoma Pronounced –(oss-tee-oh-JEN-ic sar-KOH-mah) Defined –Malignant tumor arising from bone –Also known as osteosarcoma

29. 29 Osteochondroma Pronounced –(oss-tee-oh-kon-DROH-mah) Defined –Most common benign bone tumor –Most frequently involves the femur and tibia

30. 30 Paget’s Disease Pronounced –(PAJ-ets dih-ZEEZ) Defined –Nonmetabolic disease of the bone –Characterized by excessive bone destruction and unorganized bone formation by the osteoblasts Bone is weak and prone to fractures

31. 31 Spinal Stenosis Pronounced –(SPIGH-nal stin-OH-sis) Defined –Narrowing of the vertebral canal, nerve root canals, or intervertebral foramina Openings of the lumbar spinal canal –Causes pressure on nerve roots prior to their exit from the foramina

32. 32 Talipes Equinovarus Pronounced –(TAL-ih-peez eh-kwine-oh-VAIR-us) Defined –Clubfoot

33. 33 Talipes

34. 34 Abnormal Curvature of the Spine Kyphosis –Outward curvature = humpback or hunchback Lordosis –Inward curvature = swayback Scoliosis –Lateral (sideward) curvature

35. 35 Abnormal Curvature of the Spine

36. 36 Fracture: Broken Bone Closed fracture –Break in the bone but no open wound in skin –Simple fracture Open fracture –Break in the bone, as well as an open wound in skin –Compound fracture

37. 37 Complete fracture –Break extends through the entire thickness of bone Incomplete fracture –One side of bone is broken and one side of bone is bent considerably but not broken –Greenstick fracture Fracture: Broken Bone

38. 38 Compression fracture –Caused by bone surfaces being forced against each other Impacted fracture –Direct force causes bone to break –Forces broken end of smaller bone into broken end of larger bone Fracture: Broken Bone

39. 39 Colle’s fracture –Break occurs at lower end of the radius –Within one inch of connecting with wrist bones Hairline fracture –Minor fracture in which the bone continues to be in perfect alignment –Also known as a stress fracture Fracture: Broken Bone

40. 40 Pathological fracture –Bone is weakened by a preexisting disease –Break is in response to a force that would not cause a normal bone to break Treatment of fractures –Closed reduction –Open reduction Fracture: Broken Bone

41. DIAGNOSTIC TECHNIQUES, TREATMENTS AND PROCEDURES Skeletal System

42. 42 Diagnostic Techniques, Treatments, and Procedures Bone scan –Intravenous injection of a radioisotope, which is absorbed by bone tissue –Followed by scanning of the skeleton approximately three hours later to detect areas where the bone absorbs the isotope

43. 43 Diagnostic Techniques, Treatments, and Procedures Bone marrow aspiration –Removal of a small sample of bone marrow from a selected site with a needle –Specimen is examined under a microscope –Sterile technique

44. 44 Diagnostic Techniques, Treatments, and Procedures Noninvasive procedures for evaluating bone density –Dual Photon Absorptiometry –Dual Energy X-Ray Absorptiometry