The Skeletal System

1. Chapter 13 The Skeletal System

2. Two Divisions of the Skeletal System • Axial skeleton • Made up of the spinal cord, skull, and rib cage • Appendicular skeleton • Made up of the bones of the arms, legs, hands, feet, shoulders, and pelvis

3. The Major Bones of the Body

4. Bone Structure • Over 20% of the weight of bone is water. • Two thirds of the remainder are minerals and one third, organic matter. • Main minerals are calcium, phosphorus, and magnesium • Organic matter is primarily collagen, a type of protein fiber that forms the matrix (intercellular substance) of the bone.

5. Number of Bones • At birth, a baby has 270 bones. • As the child grows, some of the bones fuse together so that in adulthood there are only 206. • The smallest bones in the body are the malleus, incus, and stapes of the middle ear.

6. Functions of the Skeletal System • Supports the body • Protects the vital organs • Provides a point for muscle attachment • Gives shape to the body • Forms red blood cells, white blood cells, and platelets • Bones store calcium needed for heartbeat, muscle contraction, and clotting

7. Spinal Column

8. The Divisions of the Spinal Column

9. The Divisions of the Spinal Column

10. The Skull

11. Fontanels • Large diamond-shaped anterior areas where the frontal and parietal bones of the skull meet and the triangular space posteriorly where the occipital bones meet the parietal bones of the skull are known as the fontanels or soft spots

12. The Rib Cage

13. The Structure of Long Bones

14. The Structure of Long Bones • Hollow cylinders made up of three regions • Diaphysis: the long part or shaft • Epiphysis: the ends of the bone • Metaphysis: link between diaphysis and epiphysis

15. How Long Bones Grow • Early in life the ends of the bones (epiphysis) are mainly cartilage. • Later, the cartilage becomes a strip that permits new tissue growth and bone length.

16. Bones of the Hands and Feet

17. The Pelvic Girdle

18. Joints • Joints are found wherever two bones come together in the body to permit movement – Diarthrosis: a movable joint, such as the knee or elbow – Amphiarthrosis: partially movable joint, such as where the ribs attach to the spine – Synarthosis: immovable joints, such as the cranial sutures in the skull

19. Parts of Synovial Joints • Articular cartilage • Slippery surface that enables the joint to absorb shock during movement • Bursa • Saclike capsules that hold synovial fluid • Synovial cavity • Lubricates joints and reduces friction

20. Types of Fractures

21. Treatment for a Fracture • Immobilization of the affected part and prevention of shock are the primary concerns. • Elevation, splinting, casting, and/or surgical repair may be required to realign the broken ends of the bone.

22. The Healing Process of a Fracture • A hematoma forms at the fracture site and this begins the inflammatory reaction that initiates healing. • A fibrous bridge begins to form between bone fragments. • Cells in this bridge begin to accumulate calcium and form a callus that forms new bone.

23. Bone Healing Process • A hematoma forms at the fracture site and this begins the inflammatory reaction that initiates healing. • A fibrous bridge begins to form between bone fragments. • Cells in this bridge begin to accumulate calcium and form a callus that forms new bone.

24. Bone Healing Process

25. Fatty Embolus • A mass of foreign matter that circulates within blood vessels as a complication from the fracture of a long bone

26. Amputation • The surgical removal of an extremity • May be the result of trauma, tumors, lack of circulation, or disease complications • Following amputation, a patient may experience the sensation that the missing limb is still present. • This is described as a phantom limb condition.

27. Diagnostic Examinations • Arthroscopy • Endoscopic procedure that permits direct visual inspection of a joint, most often the knee • Bone scan • Precise nuclear medicine procedure using small amounts of a radioactive substance that are injected into a vein to help diagnose the presence of disease based on structural appearance

28. Diagnostic Examinations • Computed tomography (CT scan) • A special X-ray in that the X-ray tube moves around the patient • A computer takes the information and reconstructs a cross-sectional (axial) “slice” of the patient. • Multiple slices are taken that allow the provider to determine the anatomy in three dimensions

29. Diagnostic Examinations • Magnetic resonance imaging (MRI) • Process uses strong magnets that cause all of the protons in the field to “line up” • Radio waves are then passed through the patient, causing the protons to resonate. • A computer takes this information and constructs images in any plane.

30. Diagnostic Examinations • X-ray • A frequently-used test that evaluates the condition of bones in cases such as dislocations, sprains, and fractures • Can also be used to determine bone structure changes like those occurring in some metabolic conditions such as acromegaly (gigantism) and osteoporosis or with Paget’s disease.

31. Arthritis • Joint inflammation • There are more than 100 different forms of arthritis. • Currently affects about 40 million Americans, the larger percentage being women • Most common forms are osteoarthritis, rheumatoid arthritis, gout, and lupus arthritis

32. Osteoarthritis • Common form of arthritis; no cure • Results in progressive deterioration of joint cartilage, most often at the hips and knees • Affects many people as they grow older. • Symptoms result from the breakdown of cartilage between bones and of the bones themselves. • Also known as degenerative joint disease

33. Rheumatoid Arthritis • Chronic systemic inflammatory disease attacking joints and surrounding tissues • An intermittent disease with periods of remission • Three times more common in females than males • Most often striking between the ages of 35 and 45

34. Gout • Metabolic disease; results in severe joint pain, especially at night. • Most often affects the great toe but can involve other joints • Pain results from deposits of urates, which are overproduced or retained by the body

35. Gout • Often associated with another disease or because of cell destruction by chemotherapy. • May also follow drug therapy that interferes with urate excretion

36. Bursitis • A painful inflammation of the bursa • Bursa - a sac located around a joint containing lubricating fluid that allows muscles and tendons to move freely over bony surfaces • Occurs most frequently at the hip, shoulder, or knee

37. Carpal Tunnel Syndrome • Compression of the median nerve at the wrist that results from repetitive motion • Tendon sheaths become inflamed, causing swelling, which presses the median nerve against the transverse ligament

38. Congenital Hip Dysplasia • Hip abnormality present at birth that may affect one or both joints • Unstable: Hip is easily dislocated. • Incomplete: The head of the femur is on the edge of the hip socket. • Complete: The head of the femur is completely outside the hip socket.

39. Dislocation and Epicondylitis • Dislocation • Displacement of bones in a joint so that the regularly meeting surfaces are no longer in contact with each other • Epicondylitis • Inflammation of the forearm extensor tendon where it attaches to the humerus • Also called tennis elbow

40. Hallux Valgus • Common in women • A lateral deviation of the great toe with enlargement of the first metatarsal head and a bunion formation • A bunion may be associated with a painful bursa.

41. Herniated Disk • The soft gel-like material within an intervertebral disk has been forced through the disc’s outer surface. • Extruded material may cause pressure on a spinal nerve exiting the spinal cord or may impinge on the spinal cord itself

42. Kyphosis • Bowing of the back, usually at the thoracic level, resulting from improper vertebral alignment • Two types • Adolescent • Adult

43. Lordosis and Lumbar Myositis • Lordosis • Abnormal anterior convex curvature of the lumbar spine • Commonly referred to as swayback • Myositis • Inflammation of the lumbar region muscles of the back

44. Osteoporosis • Metabolic bone disorder that results in the loss of bone mass • Loss of calcium and phosphorus causes the bones to become brittle and break easily • Generally affects women after menopause

45. Osteoporosis

46. Scoliosis • Lateral curvature of the spine, usually in the thoracic region, associated with rotation of the spinal column • May also be lumbar or involve both • Thorax usually curves to the right while the lumbar curves left • Because the body has to maintain balance, the cervical spine will also curve left.

47. Sprains and Subluxation • Sprain • The complete or incomplete tear in the supporting ligaments of a joint • Follows a severe twisting action of a joint • Subluxation • The partial or incomplete dislocation of the articulating surfaces at the joints

48. Temporomandibular Disorders (TMD) • A condition of the jaw that is described as a feeling that the jaw has come unhinged • For unknown reasons, 90% of sufferers are women.

49. Replacing Bone and Joints • When bone is destroyed by injury, cancer, or an infectious process, providers may use bone taken from other places in the body. • Replacing worn or damaged joints is a commonly performed procedure. • The knees and hips are the joints most often affected by the wear and tear of movement and supporting the body.

50. System Interaction Associated with Disease Conditions • The skeletal system provides the framework upon which the body structure is supported. • Bones do not function alone in either a healthy or diseased condition. • See Table 13-1.