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 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 Types of Muscles

4 Cardiac –Forms the wall of the heart –Involuntary Types of Muscles

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 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 Muscles of the Head and Neck

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

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

9 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 Muscles of the Upper Extremities

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 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 Muscles of the Lower Extremities

15 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 Muscles of the Lower Extremities

16 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 Muscles of the Lower Extremities

PATHOLOGICAL CONDITIONS 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

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

36 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 Movements of Joints

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

PATHOLOGICAL CONDITIONS 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

51 Rheumatoid Arthritis Pronounced –(ROO-mah-toyd ar-THRY-tis) Defined –Chronic, systemic, inflammatory disease that affects multiple joints of the body –Mainly the small peripheral joints

52 Sprains Pronounced –(SPRAYN) Defined –Injury involving ligaments that surround and support a joint Caused by a wrenching or twisting motion

53 Systemic Lupus Erythematosus Pronounced –(sis-TEM-ic LOO-pus er-ih-them-ah-TOH- sis) Defined –Chronic, inflammatory connective tissue disease affecting the skin, joints, nervous system, kidneys, lungs, and other organs –Characteristic “butterfly rash” appears on the face

DIAGNOSTIC TECHNIQUES, TREATMENTS AND PROCEDURES Joints

55 Diagnostic Techniques, Treatments, and Procedures Arthrocentesis –Surgical puncture of a joint with a needle for the purpose of withdrawing fluid for analysis Arthrography –Process of X-raying the inside of a joint, after injecting the joint with a contrast medium

56 Diagnostic Techniques, Treatments, and Procedures Arthroplasty –Surgical repair of a joint Arthroscopy –Visualization of the interior of a joint using an endoscope

57 Erythrocyte Sedimentation (sed) Rate –Blood test that measures the rate at which erythrocytes settle to the bottom of a test tube filled with unclotted blood Diagnostic Techniques, Treatments, and Procedures

58 Rheumatoid factor –Blood test that measures the presence of unusual antibodies that develop in a number of connective tissue diseases, such as rheumatoid arthritis Diagnostic Techniques, Treatments, and Procedures