Chapter 1 Lecture Articulations HUMAN ANATOMY Articulations The

Chapter 1 Lecture Articulations HUMAN ANATOMY Articulations The Skeletal System: Articulations

Introduction • Joints, or articulations, are connections between bones that may or may not permit movement. – Cartilage, fluid, or dense connective tissues is usually involved in holding joints together. • Joints maybe classified structurally or functionally

Classification of Articulations - Structural Classification 1) Fibrous – No joint cavity – fibrous tissue a) Suture – very thin fibrous tissue if fused – synostoses b) Syndesmosis – broader fibrous tissue fontanel c) Gomphosis – peg in cone example: tooth in jaw 2) Cartilaginous – No joint cavity – Cartilage a) Synchondrosis – hyaline cartilage epiphyseal plate b) Symphysis – fibrocartilage symphysis pubis and intervertebral disks 3) Synovial – Joint (Synovial) cavity a) Gliding – intertarsal b) Hinge – knee and ankle c) Pivot – atlantoaxial d) Condyloid or Ellipsoidal – wrist e) Saddle – thumb f) Ball and Socket – should and hip

Classification of Articulations Functional Classification of Joint 1) Synarthroses – Immovable Joints a) Suture b) Gompohsis c) Synchondrosis 2) Amphiarthrosis – Slightly movable joints a) Symphysis – pubic symphysis b) Syndesmosis - tibia and fibula 3) Diarthrosis – Freely movable a) Gliding – gliding b) Hinge – flex and extend (1 plane) c) Pivot – rotation – 1 plane d) Condyloid or Ellipsoidal – 2 planes flex, extend, abduct and adduct e) Saddle – – 2 planes flex, extend, abduct and adduct f) Ball and Socket – (3 planes) flex, extend; abduct adduct; and medial and lateral rotation

Synarthroses (Immovable Joints) • Sutures are joints found only in the skull. – Bony edges interlock and short dense connective tissue fiber hold the bones together. • A gomphosis is the joint between a tooth and the alveolar fossa of the maxillae or mandible. – Periodontal ligaments (PDL) hold the tooth to the bone in the gomphosis. • A synchondrosis is a joint in which hyaline cartilage separates the ends of the bones involved in the joint. • A synostosis occurs if bones fuse together to form one bone.

Amphiarthroses (Slightly Movable Joints) • A syndesmosis occurs when to bones are connected by relatively long connective tissue ligaments. • Connecting bones using a fibrocartilage pad forms a symphysis.

Diarthroses (Freely Movable Joints) • Synovial joints are typically found at the ends of long bones in the upper and lower limbs. • All synovial joints have six basic characteristics: – A joint capsule – Articular cartilages – A joint cavity filled with synovial fluid – A synovial membrane lining the joint capsule

Synovial Joints Figure 8. 1 Structure of a Synovial Joint

Synovial Fluid • Synovial fluid has three functions: – Lubricates the surfaces of the articular cartilages on the ends of the bones. – Nourishes the chondrocytes by entering and exiting the articular cartilages due to the forces acting on the joint. – Acts as a shock absorber.

Types of Movements • Angular movements • Rotation

Special Movements • Movements at the ankle include: – Eversion/inversion – Dorsiflexion/plantar flexion • Movement of the vertebral column includes: – Lateral flexion • Movement of the pollex (thumb): – Opposition/reposition

Special Movements • Movements that occur at many joints include: – Protraction: anterior movement in the horizontal plane – Retraction: posterior movement in the horizontal plane – Elevation: cranial movement in the vertical axis – Depression: caudal movement in the vertical axis

Structural Classification of Synovial Joints • Plane joints: – Nonaxial or multiaxial • Hinge joints: – flexion and extension • Pivot joints: – rotational movements

Structural Classification of Synovial Joints • Condylar joints: – flexion/extension and abduction/adduction • Saddle joints: – biaxial joints that also allow circumduction • Ball and socket joints: – triaxial joints

The Temporomandibular Joint Figure 8. 7 a, b The Temporomandibular Joint (TMJ)

Intervertebral Articulations Figure 8. 8 a Anterior Vertebral Column Figure 8. 8 b Lateral Vertebral Column

Vertebral Movements • There are four possible movements of the vertebral column: – Anterior flexion, or bending forward – Extension, or bending backward – Lateral flexion, or bending to the side – Rotation–twisting

The Sternoclavicular Joint Figure 8. 10 The Sternoclavicular Joint

The Shoulder Joint Figure 8. 11 a The Anterior Shoulder Figure 8. 11 b The Lateral Shoulder

The Shoulder Joint coracohumeral, glenohumeral, acromioclavicular, glenoid labrum, & subscapular bursa Figure 8. 11 c Sectional Shoulder Figure 8. 11 d Superior Shoulder

The Elbow Joint Elbow: annular, ulnar & radial collateral ligament as well as biceps tendon Figure 8. 12 a Medial Elbow Figure 8. 12 d Longitudinal Elbow

The Wrist Figure 8. 13 b Wrist Joints Figure 8. 13 c Wrist Ligaments

The Joints of the Hand Figure 8. 13 d Joints of the Hand

The Hip Joint Hip: iliofemoral, pubofemoral, ischiofemoral, acetabular labrum & capitate (teres) ligament Figure 8. 14 a Lateral Hip Figure 8. 14 c Posterior Hip

The Hip Joint Figure 8. 14 b Anterior Hip Figure 8. 15 a Sectional Hip

The Knee A recent MRI has confirmed a sprained MCL for the Chargers running back, who Figure 8. 16 a Anterior Knee Figure 8. 16 b Parasagittal Knee is expected to miss four to five weeks, according to the NFL Network.

The Knee • • • medial meniscus lateral meniscus Transverse ligament patellar ligament prepatellar bursa fibular collateral ligament anterior cruciate ligament tibial collateral ligament posterior cruciate ligament

The Knee Figure 8. 17 c Anterior Knee

Knee

The Ankle and Foot Figure 8. 18 a Ankle and Foot Figure 8. 18 b Ankle and Foot MRI

Arthritis • Osteoarthritis – It is a chronic condition in which the material that cushions the joints, called cartilage, breaks down. This causes the bones to rub against each other, causing stiffness, pain and loss of joint movement. • Rheumatoid arthritis – RA is an autoimmune disease. This means that certain cells of the immune system start attacking joints • Gout (gouty arthritis) – – sudden burning pain, stiffness, and swelling in a joint, usually a big toe. Over time, they can harm your joints, tendons, and other tissues. Gout is most common in men. Gout is caused by too much uric acid in the blood. When uric acid levels in your blood are too high, the uric acid may form hard crystals in your joints.