Chapter 15 Musculoskeletal System Musculoskeletal System 1 Bones

Chapter 15 Musculoskeletal System

Musculoskeletal System • 1. Bones (oste/o=bone)- provides the framework around which the body is constructed and protect and support internal organs • 2. Joints (arthr/o; articul/o= joint)- places at which bones come together • 3. Muscles (my/o; myos/o=muscle)- attached to bones, or to internal organs and blood vessels. They are responsible for movement

Terms • -Orthopedic- (orth/o= straight; ped/i= child); physicians who treat bone & joint disease • -Rheumatologist- (rheumat/o= watery flow); one who specializes in the study of joint diseases (because joint diseases are marked by collection of fluid in joint spaces • Chiropractor- (chir/o= hand)- use physical means to manipulate the spinal column • -Osteopathy- (oste/o=bone; path= disease)- p/t to diseases of the bone – Osteopathic physicians (DO)

Bones • -Complete organs composed of connective tissue called osseous (bony) tissue ; plus a rich supply of blood vessels and nerves • Osseous tissue consists of osteocytes (bone cells), collagen (dense connective tissue), and calcium salts • Ossification- bone formation • Osteoblasts- immature osteocytes that produce bony tissue that replaces cartilage during ossificationa • Osteoclasts- (-clast=to break); large cells that function to reabsorb, digest bony tissue. They enlarge the inner bone cavity so bones do not become too heavy • *Calcium and Phosphorus are minerals necessary to produce enzymes to give bones strength

Structure of bones • 206 bones in the body • Long bones- found in thigh, lower leg, and upper and lower arm; strong and broad at end where they join other bones. They have large surface areas for muscle attachment. • Short bones- found in wrist and ankle and are small with irregular shapes • Flat bones- cover soft body parts • Sesamoid bones- small, round and resembles a sesame seed in shape. They are found near joint. • What is the largest sesamoid bone in the body? __________

Structure of bones • Diaphysis- shaft or middle region of a long bone • Epiphysis- end of the long bones • Metaphysis- flared portion of the bone • Periosteum- strong, fibrous, vascular membrane that covers the surface of long bones • Articular cartilage- where the ends of long bones and the surface of any bone meet • *the bones of a fetus are mostly made of cartilage

Structure of bones • Compact bone- layer of hard, dense bone that lies under the periosteum near the diaphysis of long bones • Haversian canal- small canals containing blood vessels that bring O 2 and nutrients; remove waste products (CO 2) • Cancellous bone- “spongy or trabecular”; porous and less dense than compact bone; red bone marrow is located here – Trabeculae- spongy latticework

Bone Processes • Bone processes are enlarged areas to serve as attachment for muscles and tendons • Bone head- rounded end of a bone separated from the body of the bone by a neck • Greater Trochanter- large process on the femur for attachment of tendons and muscle (lesser trochanter is just smaller) • Condyle- rounded, knuckle-like process at a joint • Tubercle- rounded process on many bones for attachment of tendons and muscles – Tuberocity- small rounded elevation on a bone

Bone openings or hollow regions • Fossa- shallow cavity in or on a bone • Foramen- opening for blood vessels and nerves • Fissure- narrow, deep, slit-like opening • Sinus- hollow cavity within a bone

A) Divisions of a long bone and interior bone structure. B) Composition of compact

Bone processes on the femur and humerus. Fig. 15 -2 AB. Copyright © 2001

Cranial bones (lateral view). Fig. 15 -3. Copyright © 2001 by W. B. Saunders

Cranial bones (looking downward at floor of cranial cavity). Fig. 15 -4. Copyright ©

Facial bones. Fig. 15 -5. Copyright © 2001 by W. B. Saunders Company. All

Sinuses of the skull. Fig. 15 -6. Copyright © 2001 by W. B. Saunders

Vertebral column. Fig. 15 -7. Copyright © 2001 by W. B. Saunders Company. All

Bones of the Thorax (chest cavity) • Clavicle • Scapula • Sternum • Ribs • Acromion

Bones of the Arm and Hand • Humerus – Olecranon • • • Ulna Radius Carpals Metacarpals Phalanges

Pelvic Bones • Pelvic girdle – pelvis; collection of bones composed of: ilium ischium pubis *Pubic Symphysis. Anterior part of pelvis where cartilage connects

Bones of the Leg and Foot • Femur • Patella • Tibia -Malleous • Fibula • Tarsals -(7 bones)calcaneus- heel bone is the largest • Metatarsals • Phalanges of the toes

Bones of the thorax, pelvis, and extremities. Fig. 15 -9. Copyright © 2001 by

Bones of the foot. A B Fig. 15 -11 AB. Copyright © 2001 by

Fractures- break in a bone • Closed fx – bone is broken but no open wound • Open fx- bone is broken and a fragment of bone protrudes through skin • Crepitus- crackling sound when ends of bones rub each other or roughened cartilage • Colles fx- occurs near the wrist joint at lower end of radius • Comminuted fx- bone splintered or crushed into several pieces • Compression fx- bone is compressed • Greenstick fx- bone is partially broken; typically occurs in children • Impacted fx- one fragment is driven firmly into another

$Open fracture$

Open fracture

Colles Fracture

Comminuted Fracture

Pathologic conditions • Ewing Sarcoma- malignant bone tumor • Exostosis- bony growth arising from the surface of bone (ex=out; -ostosis= bone condition) • Osteogenic sarcoma- malignanat tumor arising from bone (osteosarcoma) • Osteomalacia- softening of bone (loss of calcium) • Osteomyelitis- inflammation of bone & bone marrow due to infection • Osteoporosis- decrease in bone density (mass); thinning of bone • Osteopenia- interior of bones is diminished in structure • Osteodystrophy- poor formation of bone

Pathological Conditions • Talipes- congenital abnormality in hindfoot (involving talus; clubfoot) • Kyphosis- “hunchback”; spine curvature in thoracic cavity • Lordosis- lumbar spine curves outward • Scoliosis- lateral curvature of spine • Sciatica- pain radiating down the leg (nerve)

Scanning electromicrograph (A: Normal bone; B: Bone with osteoporsis). (From Dempster DW, Shane E, Horbert W, et al: A simple method for correlative light and scanning electron microscopy of human iliac crest bone biopsies: qualitative observations in normal and osteoporotic subjects. J Bone Miner Res, 1986; 1: 15. ) Copyright © 2001 by W. B. Saunders Company. All rights reserved. Back MENU Fig. 15 -15 AB. Forward

Types of joints • Joint (arthr/o)- a coming together of two or more bones • Suture joint- immovable joint • Synovial joint- freely moveable • Joint capsule- bones in a synovial joint composed of fibrous tissue • Ligaments- connect bone to bone; thick fibrous band of connective tissue – Sprain - trauma to a joint with pain, swelling and injury to ligaments • Articular Cartilage- covers the smooth end of the joints surface

Types of Joints • Synovial Membrane- lies under the joint capsule and lines the synovial cavity between the bones. - The synovial fluid contains water and nutrients that lubricate the joint. - Bursae (bursa)-sac that contains synovial fluid that are located near but not within a joint - Tendons -connective tissue that connects muscle to bone - Tenorrhaphy- suture of a tendon

The knee (A: Sagittal; B: Frontal). A B Fig. 15 -18 AB. Copyright ©

Pathological conditions • Arthritis- inflammation of a joint – Ankylosing Spondylitis- chronic, progressive arthritis with stiffening of joints – Gouty Arthritis -inflammation and painful swelling of joints caused by excessive uric acid in the body (hyperuricemia); typically affects the big toe and is often called “podagra” – Osteoarthritis -(OA); progressive, degenerative joint disease characterized by loss of articular cartilage and hypertrophy of bone

Pathological Conditions • Rheumatoid Arthritis (RA)- Chronic disease in which joints become inflamed and painful. It is thought to be an autoimmune reaction against joint tissues – Pyrexia (fever) – symptom of RA • Ankylosis - condition of stiff, bent joint • Bunion - abnormal swelling of the medial aspect of the joint between the big toe and first metatarsal • Carpal Tunnel Syndrome-compression of the median nerve as is passes between the ligament, bones and tendons of the wrist. • Arthroplasty- surgical repair of a joint • Spondyloliasthesis- slipping or subluxation of vertebrae

Pathological Conditions • Herniation of an intervertebral diskabnormal protrusion of a fibrocartilaginous intervertebral disc into the spinal nerves • Ganglion cyst- A fluid-filled cyst arising from the joint capsule or a tendon • Dislocation -Displacement of a bone from its joint – Reduction= restoration of bones to normal position – Subluxation= partial dislocation

Pathological Conditions • Lyme Disease- a recurrent disorder marked by severe arthritis, myalgia, malaise, and neurologic and cardiac syndromes • Sytemic Lupus Erythematosus (SLE)chronic inflammatory autoimmune disease involving joints, skin, kidneys, nervous system, heart and lungs; characterized by ‘butterfly rash”

Osteoarthritis and rheumatoid arthritis. Fig. 15 -19. Copyright © 2001 by W. B. Saunders

Carpal tunnel syndrome. Fig. 15 -20 AB. Copyright © 2001 by W. B. Saunders

Protrusion of an intervertebral disc. *Laminectomy- opertation to relieve symptoms of a slipped disk

Muscles • Cardiac muscle- striated in appearance but is like smooth muscle in action; no conscious controlled; • Smooth muscle- involuntary or visceral muscle that move internal organs. They have no dark or light bands, fibrils, or cytoplasm • Leiomyosarcoma- malignant tumor of smooth muscle • Striated muscle- voluntary or skeletal muscle that move all bones – Fascia- fibrous tissue that envelops and separates muscles and contains the blood, lymph, and nerves

Muscles • Skeletal muscle- over 600 in the human body. • The point of attachment of the muscle to a stationary bone is called origin (beginning). • When the muscle contracts, another bone to which it is attached to does move. The point of junction of the muscle to the bone that does move is called the insertion of the muscle. • *Most often, the origin of a muscle lies proximal in the skeleton and insertion lies distal. • Atrophy- wasting away of muscle (shrinking of size)

Origin and insertion of the biceps. Fig. 15 -26. Copyright © 2001 by W.

Terms for muscle/joint movement • • • Abduction Adduction Dorsiflexion Plantarflexion Extension Flexion Supination Pronation Rotation

Types of muscular actions. Fig. 15 -27. Copyright © 2001 by W. B. Saunders

Abbreviations • • • ROM ACL PCL MCL LCL EMG RA PT NSAID TMJ THR TKR