Muscles and Joints

1. Muscles and Joints CHAPTER 7

2. Muscles Overview • Muscles support and maintain body posture through a low level of contraction • Skeletal muscles produce a substantial amount of heat when they contract

3. Types of Muscles • Skeletal • Attaches to the bones of the skeleton • Voluntary/striated • Operates under conscious control • Smooth • Called visceral muscle • Involuntary/not striated • Not under conscious control

4. Types of Muscles • Cardiac • Forms the wall of the heart • Involuntary

5. Attachment of Muscles • Tendon • Attaches muscles to bones • Point of origin • Point of attachment of the muscle to the bone that is less movable • Point of insertion • Point of attachment to the bone that it moves

6. Muscles of the Head and Neck • Buccinator • Located in fleshy part of cheek • Temporal • Located above and near the ear • Masseter • Located at the angle of the jaw • Raises the mandible and closes the jaw

7. Muscles of the Head and Neck • Sternomastoid • Also called the sternocleidomastoid • Extends from the sternum upward along the side of the neck to the mastoid process

8. Muscles of the Upper Extremities • Trapezius • Triangular-shaped muscle • Extends across the back of the shoulder • Covers back of neck • Inserts on clavicle and scapula

9. Muscles of the Upper Extremities • Latissimus Dorsi • Originates from vertebrae of lower back • Crosses lower half of thoracic region • Passes between humerus and scapula • Inserts on anterior surface of humerus • Forms the posterior border of the armpit

10. Muscles of the Upper Extremities • Pectoralis Major • Large, fan-shaped muscle • Crosses the upper part of the front chest • Originates from sternum • Crosses over to humerus

11. Muscles of the Upper Extremities • Deltoid • Covers the shoulder joint • Originates from clavicle and scapula • Inserts on lateral side of the humerus

12. Muscles of the Upper Extremities • Biceps Brachii • Muscle has two heads • Originates from scapula • Inserts on the radius

13. Muscles of the Upper Extremities • Triceps Brachii • Muscle has three heads • Originates from scapula and humerus • Inserts onto olecranon process of the ulna • At the elbow

14. Muscles of the Lower Extremities • Gluteus Maximus • Forms most of the fleshy part of the buttock • Originates from ilium and inserts in the femur • Gluteus Medius • Located above the upper outer quadrant of the gluteus maximus muscle • Originates from posterior part of ilium • Inserts in greater trochanter of the femur

15. Muscles of the Lower Extremities • Quadriceps Femoris • Forms anterior part of the thigh • Help extend the thigh • Hamstring Muscles • Located in posterior part of the thigh • Help flex leg on the thigh • Help extend the thigh

16. Muscles of the Lower Extremities • Gastrocnemius • Main muscle of the calf • Attaches to heel bone by way of Achilles tendon • Used to plantar flex foot and flex toes • Tibialis Anterior • Positioned on the front of the leg • Used to dorsiflex foot and turn foot inward

17. PATHOLOGICALCONDITIONS Muscles

18. Muscular Dystrophy • Pronounced • (MUSS-kew-lar DIS-troh-fee) • Defined • Group of genetically transmitted disorders • Characterized by progressive weakness and muscle fiber degeneration • No evidence of nerve involvement or degeneration of nerve tissue

19. Polymyositis • Pronounced • (pol-ee-my-oh-SIGH-tis) • Defined • Chronic, progressive disease affecting the skeletal muscles • Characterized by muscle weakness and degeneration • Atrophy

20. Rotator Cuff Tear • Pronounced • (ROH-tay-tor kuff TAIR) • Defined • Tear in muscles that form a “cuff” over upper end of arm • Rotator cuff helps to lift and rotate the arm • Also helps to hold head of humerus in place during abduction of arm

21. Rotator Cuff Tear

22. DIAGNOSTIC TECHNIQUES, TREATMENTS, AND PROCEDURES Muscles

23. Diagnostic Techniques, Treatments, and Procedures • Electromyography • Process of recording strength of contraction of a muscle when stimulated by electric current • Muscle biopsy • Extraction of a specimen of muscle tissue, through biopsy needle or incisional biopsy, for purpose of examining it under a microscope

24. Joints Overview • Joint = articulation • Point at which two individual bones connect • Joints determine degree of movement • Movement ranges from free to limited • Suture = immovable joint • Purpose is to bind bones together

25. Classification of Joints(Structural) • Fibrous • Surfaces of bone fit closely together • Held together by fibrous connective tissue • Immovable joint • Example: Suture between the skull bones

26. Classification of Joints(Structural)

27. Classification of Joints(Structural) • Cartilaginous • Bones are connected by cartilage • Limited movement joint • Example: Symphysis • Joint between the pubic bones of the pelvis

28. Classification of Joints(Structural)

29. Classification of Joints(Structural) • Synovial • Space between the bones = joint cavity • Joint cavity lined with synovial membrane • Synovial membrane secretes synovial fluid • Bones are held together by ligaments • Free movement joint • Example = shoulder

30. Classification of Joints(Functional) • Hinge • Allows a back and forth type motion • Example = elbow • Ball-and-Socket • Allows movement in many directions around a central point • Example = shoulder joint and hip joint

31. Classification of Joints(Functional)

32. Movements of Joints • Flexion • Bending motion • Decreases angle between two bones • Extension • Straightening motion • Increases angle between two bones

33. Movements of Joints • Abduction • Movement of a bone away from midline of the body • Adduction • Movement of a bone toward midline of the body

34. Movements of Joints • Supination • Act of turning the palm up or forward • Pronation • Act of turning the palm down or backward

35. Movements of Joints • Dorsiflexion • Narrows the angle between the leg and the top of the foot • Foot is bent backward, or upward, at the ankle

36. Movements of Joints • Plantar Flexion • Increases angle between the leg and the top of the foot • Foot is bent downward at the ankle • Toes pointing downward, as in ballet dancing

37. Movements of Joints • Rotation • Turning of a bone on its own axis • Circumduction • Movement of an extremity around in a circular motion • Can be performed with ball-and-socket joints

38. PATHOLOGICALCONDITIONS Joints

39. Adhesive Capsulitis • Pronounced • (add-HE-sive cap-sool-EYE-tis) • Defined • Shoulder condition characterized by a stiffness of the shoulder, limited shoulder movement, and pain • Also known as “frozen shoulder”

40. Arthritis • Pronounced • (ar-THRY- tis) • Defined • Inflammation of joints

41. Ankylosing Spondylitis • Pronounced • (ang-kih-LOH-sing spon-dil-EYE-tis) • Defined • Type of arthritis that affects the vertebral column • Causes deformities of the spine

42. Bunion (Hallux Valgus) • Pronounced • (BUN-yun) (HAL-uks VAL-gus) • Defined • Abnormal enlargement of the joint at the base of the great toe

43. Dislocation • Pronounced • (diss-loh-KAY-shun) • Defined • Displacement of a bone from its normal location within a joint • Causes loss of function of the joint

44. Ganglion • Pronounced • (GANG-lee-on) • Defined • Cystic tumor developing on a tendon • Sometimes occurs on back of wrist

45. Gout • Pronounced • (GOWT) • Defined • Acute arthritis that is characterized by inflammation of the first metatarsal joint of the great toe

46. Herniated Disk • Pronounced • (HER-nee-ay-ted disk) • Defined • Rupture of the central portion of the vertebral disk through the disk wall and into the spinal canal • Also called a ruptured disk or a slipped disk

47. Herniated Disk

48. Lyme Disease • Pronounced • (LYME dih-ZEEZ) • Defined • Acute, recurrent inflammatory infection, transmitted through the bite of an infected deer tick

49. Osteoarthritis • Pronounced • (oss-tee-oh-ar-THRY-tis) • Defined • Most common form of arthritis • Results from wear and tear on the joints, especially weight-bearing joints such as hips and knees • Also known as degenerative joint disease

50. Osteoarthritis