Overview
This lecture covered the structure and function of bones and joints, types of joint movements, and related anatomical terminology, with practical examples for identification and function.
Bone Landmarks & Identifications
- Scapula landmarks include supraspinous fossa (B), infraspinous fossa (A), glenoid cavity (F), and are identified as right/left, anterior/posterior.
- The tibia has a medial malleolus; fibula has a lateral malleolus; fibula is always lateral to tibia.
- Pelvis landmarks: acetabulum (lateral, vinegar-bowl shaped), greater/lesser sciatic notch (posterior), iliac spines (ASIS, AIIS, PSIS, PIIS), and ischial spine.
- Notable bone parts mark muscle/ligament/tendon attachments: tubercles, crests, epicondyles, lines.
Major Joints & Ligament Names
- Knee joint: includes ACL (anterior cruciate ligament), PCL (posterior cruciate ligament), MCL (medial collateral/tibial collateral), LCL (lateral collateral/fibular collateral), and menisci (medial/lateral).
- Shoulder joint: glenoid cavity, labrum (glenoid labrum), acromioclavicular and coracoclavicular ligaments, subacromial bursa.
- Hip joint: acetabular labrum, iliofemoral, pubofemoral, and ischiofemoral ligaments.
- Ligament names usually combine the bones they connect (e.g., coracoclavicular, pubofemoral).
Types of Joints & Their Functions
- Fibrous joints: held by dense connective tissue, little/no movement (synarthrotic), e.g., sutures, syndesmosis, gomphosis.
- Cartilaginous joints: connected by cartilage, some movement (amphiarthrotic), e.g., synchondrosis (temporary/permanent), symphysis (intervertebral discs, pubic symphysis).
- Synovial joints: most movable (diarthrotic), joint cavity filled with synovial fluid, articular (hyaline) cartilage covers bone ends, may contain intra-articular ligaments, menisci, bursae.
Types of Joint Movements
- Flexion: decreases angle at joint (around transverse axis).
- Extension: increases joint angle (transverse axis).
- Abduction: moves part away from midline (AP axis).
- Adduction: moves part toward midline (AP axis).
- Rotation: movement around longitudinal axis (medial/lateral).
- Circumduction: circular movement at ball-and-socket joints.
- Special movements: elevation/depression (shoulder/mandible), protraction/retraction (mandible/shoulder), dorsiflexion/plantarflexion (foot), inversion/eversion (foot), pronation/supination (forearm/wrist), opposition (thumb).
Functional Anatomy & Deductions
- Muscle actions depend on origin and insertion; contraction pulls insertion toward origin.
- Knowing bone landmarks helps deduce muscle actions and joint movements.
- Synovial joints often have bursae (bursa) to reduce friction, especially in highly mobile joints.
Key Terms & Definitions
- Synarthrotic — immovable joint.
- Amphiarthrotic — slightly moveable joint.
- Diarthrotic — freely moveable joint.
- Meniscus — cartilage disc in some synovial joints (e.g., knee).
- Labrum — fibrocartilaginous rim in ball-and-socket joints (glenoid, acetabular).
- Bursa — fluid-filled sac to decrease friction.
- Syndesmosis — type of fibrous joint with a ligament.
- Gomphosis — peg-in-socket fibrous joint (tooth).
- Synchondrosis — cartilaginous joint with hyaline cartilage.
- Symphysis — joint with fibrocartilage disc (e.g., pubic symphysis).
Action Items / Next Steps
- Review all module pictures on articulations in Canvas.
- Prepare specific questions for tomorrow’s review session.
- Study bones, joints, anatomical landmarks, types of movements, and related terminology.
- Be prepared for both multiple choice and practical (picture-based) exams on all covered material.