Musculoskeletal System Quiz

Introduction to Joints

• Joints are the points where two or more bones meet
• They are essential for movement and support within the body
• They are classified based on the material connecting the bones and the degree of movement allowed

Objectives

• Arthrology: the study of joints
• Kinesiology: the study of musculoskeletal movement
• Joints classified by freedom of movement:
  • Diarthrosis (freely movable)
  • Amphiarthrosis (slightly movable)
  • Synarthrosis (little or no movement)
• Classified by how adjacent bones are joined:
  • Fibrous
  • Cartilaginous
  • Bony
  • Synovial
• Articulation : when bones come together to form joints

Bony Joint (Synostosis)

• Gap between two bones ossifies
• Can occur in fibrous or cartilaginous joints
• Examples:
  • Frontal and mandibular bones in infants
  • Cranial sutures in elderly
  • Attachment of the first rib and sternum

Fibrous Joints (Synarthrosis)

• Collagen fibers span space between bones
• Examples:
  • Sutures
  • Gomphoses
  • Syndesmoses

Fibrous Joint -- Sutures

• Immovable fibrous joints
• Bind skull bones together
• Types:
  • Serrate (interlocking lines) - coronal, sagittal, lambdoid
  • Lap (overlapping beveled edges) - temporal and parietal
  • Plane (straight nonoverlapping edges) - palatine processes of the maxillae

Fibrous Joint -- Gomphoses

• Attachment of a tooth to its socket
• Held in place by fibrous periodontal ligament
• Collagen fibers attach tooth to jawbone
• Some movement while chewing

Fibrous Joint -- Syndesmoses

• Two bones bound by ligament only
• Most movable of fibrous joints
• Examples:
  • Interosseous membranes uniting radius to ulna and tibia to fibula
  • Radio-ulnar joints

Cartilaginous Joint

• Synchondrosis
• Symphysis

Cartilaginous Joint - Synchondrosis

• Bones joined by hyaline cartilage
• Example: rib attachment to sternum
• Other costal cartilages are joined to the sternum by synovial joints
• Epiphyseal plate in children binds epiphysis and diaphysis

Cartilaginous Joint - Symphysis

• Two bones joined by fibrocartilage
• Examples:
  • Pubic symphysis
  • Intervertebral discs
• Provides flexibility to the spine

Synovial Joint

• Space called a joint cavity separates two bones
• Most are freely movable
• Examples:
  • Humeroscapular joint
  • Elbow joint
  • Hip joint
  • Knee joint

General Anatomy of Synovial Joint

• Articular capsule encloses joint cavity
• Continuous with periosteum, lined by synovial membrane
• Articular cartilage = hyaline cartilage
• Synovial fluid is rich in albumin and hyaluronic acid
• Nourishes the articular cartilage
• Removes wastes
• Prevents friction during movements

Knee Joint

• Most complex diarthrosis
• Tibiofemoral = gliding joint with slight rotation
• Patellofemoral
• Joint capsule anteriorly consists of patella
• Extensions of quadriceps femoris tendon
• Capsule strengthened by extracapsular and intracapsular ligaments

Accessory Structures (Knee Joint)

• Menisci: cartilages that extend inward, improve the fit between bones, stabilize the joint, reduce the chance of dislocation
• Tendon : attaches muscle to bone
• Ligament : attaches bone to bone (exposed to flex and extension)
• Bursa (cushion): fibrous sac filled with synovial fluid, between adjacent muscles, bone, and skin
• Bursitis: inflammation of bursa

Axes of Rotation

• Shoulder joint has 3 degrees of freedom (multiaxial)
• Other joints are uniaxial or biaxial

Types of Synovial Joints

• Ball and socket
• Hinge
• Pivot
• Gliding
• Condyloid (ellipsoid)
• Saddle

Ball-and-Socket Joints

• Smooth hemispherical head fits in cuplike depression
• Glenoid cavity of scapula
• Head of femur into acetabulum of hip bone
• Multiaxial

Condyloid (Ellipsoid) Joints

• Oval convex surface on one bone to similarly shaped depression on the next
• Radiocarpal joint of the wrist
• Metacarpophalangeal joints of the fingers

Saddle Joints

• Each articular surface is shaped like a saddle (concave in one direction, convex in the other)
• Trapeziometacarpal joint at the base of the thumb
• Biaxial

Gliding Joints

• Flat articular surfaces slide over each other
• Limited uniaxial
• Amphiarthroses

Hinge Joints

• One bone with convex surface fits into concave depression on other bone
• Examples: ulna and humerus at elbow, femur and tibia at knee, finger and toe joints
• Uniaxial

Pivot Joints

• One bone has a projection that fits into the ringlike ligament of another bone
• Rotation of the first bone on its axis relative to the other bone
• Examples:
  • Atlantoaxial joint (dens and atlas)
  • Proximal radioulnar joint

Movements of Head and Trunk

• Flexion, hyperextension, lateral flexion
• Rotation of trunk or head

Movements of Mandible

• Lateral excursion from (sideways movement)
• Medial excursion (movement back to the midline)

Movements of Hand and Digits

• Radial and ulnar flexion
• Abduction of fingers and thumb
• Opposition of thumb
• Reposition of fingers

Movements of the Foot

• Dorsiflexion
• Plantarflexion
• Inversion
• Eversion

The Glenohumeral Joint

• Most freely movable joint in the body
• Deepened by glenoid labrum
• Supported by three glenohumeral ligaments, coracohumeral ligament, transverse humeral ligament and biceps tendon
• Important joint stabilizer musculature - rotator cuff: supraspinatus, infraspinatus, teres minor and subscapularis attaches to the glenoid cavity to make the shoulder joint stable
• 4 bursae associated with shoulder joint

Stabilizers of the Shoulder Joint

• Subacromial bursa
• Supraspinatus muscle
• Coracohumeral ligament
• Subdeltoid bursa
• Subscapularis tendon
• Transverse humeral ligament
• Biceps brachii tendon
• Glenohumeral ligaments

Tendons of Rotator Cuff Muscles

• Supraspinatus
• Subdeltoid bursa
• Infraspinatus
• Glenoid cavity (articular cartilage)
• Teres minor
• Synovial membrane
• Coracohumeral ligament
• Superior glenohumeral ligament
• Biceps brachii tendon
• Subscapular bursa
• Subscapularis tendon
• Middle glenohumeral ligament
• Inferior glenohumeral ligament

Dissection of Shoulder Joint

• Acromioclavicular joint
• Acromion of scapula
• Clavicle
• Head of humerus
• Coracobrachialis muscle
• Deltoid muscle
• Pectoralis major muscle
• Biceps brachii muscle (short and long head)

The Elbow Joint

• Single joint capsule enclosing the humeroulnar and humeroradial joints
• Humeroulnar joint is supported by collateral ligaments
• Radioulnar joint has head of radius held in place by anular ligament encircling the head

The Hip Joint

• Head of femur articulates with acetabulum,
• deepening acetabular labrum
• Blood supply to head of femur found in ligament of the head of femur,
• Joint capsule strengthened by ligaments

Dissection of Hip Joint

• Acetabular labrum
• Acetabulum
• Head of femur
• Greater trochanter
• Round ligament
• Shaft of femur

The Knee Joint

• Tibiofemoral = gliding joint with slight rotation
• Patellofemoral
• Joint capsule anteriorly consists of patella and extensions of quadriceps femoris tendon
• Capsule strengthened by extracapsular and intracapsular ligaments

Knee Joint - Sagittal Section

• Bursa under lateral head of gastrocnemius
• Joint capsule
• Articular cartilage
• Meniscus

Knee Joint - Anterior and Posterior Views

• Anterior and lateral cruciate ligaments limit anterior and posterior sliding movements
• Medial and lateral collateral ligaments prevent rotation of extended knee

Knee Joint - Superior View

• Medial and lateral meniscus absorb shock and shape the joint

Dissection of Knee Joint

• Femur - Shaft, Patellar surface, Medial/Lateral condyle
• Joint capsule
• Anterior/Posterior cruciate ligament
• Medial/Lateral meniscus
• Tibia - Lateral/Medial condyle, Tuberosity
• Patellar ligament
• Patella (posterior surface)
• Articular facets
• Quadriceps tendon

Arthritis

• Arthritis is a broad term for pain and inflammation
• Osteoarthritis: years of wear and tear
  • Articular cartilage softens and degenerates, accompanied by crackling sounds (crepitus)
  • Bone spurs develop on exposed bone tissue causing pain
• Rheumatoid arthritis, an autoimmune attack on the joint
  • Antibodies attack synovial membrane and enzymes in synovial fluid degrade the cartilage
  • Bones may ossify (grow together) , remissions (periods of relief) can occur
  • Steroids and aspirin may be used to control inflammation

Joint Prostheses

• Artificial joints replace diseased joints

Learning Outcomes Skeletal System (Part 1)

• Functions
  • Support
  • Movement
  • Protection
  • Storage of minerals and lipids
  • Blood cell production
• Structures of bone
  • Diaphysis
  • Epiphyses
  • Metaphysis
  • Articular cartilage
  • Marrow cavity
    • Red or yellow marrow
• Compact bone
  • Osteons arranged around central canals/Haversian canals
  • Formed layers/Lamallae
  • Projections from osteocytes/canaliculi
  • Perforating canals/Volkmann channels extend between adjacent osteons
• Spongy Bone
  • Trabeculae (no central canals)
• Ossification
  • Intramembranous: begins with ossification center/osteoblast differentiation, dermal bone formation
  • Endochondral: cartilage model replaced by bone, increasing bone length, appositional growth increases bone diameter
• Bone shapes
  • Long
  • Flat
  • Short
  • Irregular
  • Sesamoid
  • Sutural

Division of Skeleton

• Axial
• Appendicular - Pectoral girdle (Scapula, Clavicle) - Pelvic girdle (Ilium, Pubis, Ischium) - Upper limbs (Humerus, Radius, Ulna, etc.) - Lower limbs (Femur, Tibia, Fibula, etc.)

Openings, Processes, and Parts in Bone

• Openings
  • Fissure
• Foramen
• Fossa
• Sulcus
• Meatus
• Processes
  • Condyle
  • Facet
  • Head
  • Crest
  • Epicondyle
  • Line
  • Tuberosity
  • Tubercule

Hyoid Bones, Auditory Ossicles, and Vertebral Anatomy

• Hyoid bone:
  • Unpaired
  • U-shaped
  • Suspended from/by temporal bone via ligaments and muscles
  • Supports the larynx
• Auditory ossicles:
  • 6 (malleus, incus, stapes) - left and right
• Vertebral anatomy:
  • Vertebra: body, pedicle/roof of vertebral arch, lamina, superior/inferior articular process, transverse process, separated by intervertebral discs.
    • Cervical vertebrae
    • Thoracic vertebrae
    • Lumbar vertebrae
    • Sacrum and coccyx
    • Spinal curvature
• Rib anatomy
• Costal rib
• False rib
• Floating ribs
• Sternum

Joint classification

• Fibrous
  • Suture
  • Gomphosis
  • Syndesmosis
• Cartilaginous
  • Synchondrosis
  • Symphysis
• Synovial
  • Examples: ball-and-socket, hinge, pivot, gliding, condyloid, saddle
• Degree of Movement
  • No Movement/Immovable/Synarthrosis
  • Slight Movement/Slightly Movable/Amphiarthrosis
  • Free Movement/Freely Movable/Diarthrosis
• Ligaments and tendons

Joint Problems With Aging

• Joint problems associated with aging
• Rheumatism.
• General term for pain and stiffness.
• Arthritis
• All rheumatic diseases affecting synovial joints.
• Musculoskeletal system
• Encompasses extensive interactions between the muscular and skeletal systems
• Osteopenia and osteoporosis