MSK 2 Flashcards
Joints
Point of contact, articulation
Between bones
Always connective tissue
Structural vs. functional joint
How joint is structured vs. how it moves
2 structural classifications of joints
- Joined by solid mass of CT (fibrous, cartilaginous)
- Joined by lubricated capsule (synovial)
Types of joints
- Fibrous
- Cartilaginous
- Synovial
Ligaments
Connect bone to bone
Composed of dense CT
Intrinsic ligament
Binds bone
Extrinsic ligament
Support, ROM
Fibrous joints
Solid mass of dense irregular connective tissue
1. Suture
2. Syndesmosis
3. Gomphosis
Suture
Seam
ex. Skull
Slightly movable in kids, not in adults
Gomphosis
Bolt or nail
ex. tooth, periodontal ligament
Syndemosis
Band
ex. forearm
Cartilaginous joint
Solid mass of cartilage
1. Symphysis
2. Synchondrosis
Synchondrosis
Hyaline CT
ex. ephyseal growth plate
Symphysis
Hyaline CT
Bones connect by fibrocartilage
ex. midline bones, like pubis
Synovial joint
- Synovial capsule
- Synovial membrane
- Synovial cavity
- Synovial fluid
- Articular cartilage
- Articular disc
- Meniscus
- Labrum
- Bursa
Synovial capsule
Sleeve around two bones
Supported by collagen and tendon
Synovial membrane
Creates synovial fluid
Synovial cavity
Holds synovial fluid
Synovial fluid
Lubricates, reduces frictions, absorbs shocks
Articular cartilage
Hyaline CT, reduces friction
Articular disc
Complete disc of fibrocartilage
Meniscus
Incomplete fibrocartilage, improves fit, redistributes weight
Labrum
Fibrocartilage, deepens ball and socket
Bursa
Sac of fluid, reduces friction
Anatomical position
Standing straight with palms forwar
Adduction
Move towards body
Coronal plane
Abduction
Move away from body
Coronal plane
Flexion
Bend, decrease angle
Sagittal planee
Extension
Extend, increase angle
Sagittal plane
Circumduction
Flexion, abduction, extension, adduction
Rotation
Internal/external
Medial/lateral
Types of synovial
- Pivot
- Hinge
- Saddle
- Plane
- Condyloid
- Ball & socket
Pivot joint
Neck
Saddle joint
Thumb
Hinge joint
Elbow, knee
Ball and socket joint
Hip, shoulder
Condyloid joint
Wrist
Plane joint
Ankle
Osteoarthritis
Degenerative; break down of articular cartilage
Crystal arthritis OR gout
Uric acid deposits due to diet
Rheumatod arthritis
Autoimmune, attacks synovium
Muscles
Excitable
Contractible
Extensible
Flexible
Produce body movement, heat
Types of muscle
- Skeletal
- Smooth
- Cardiac
Skeletal muscle
Striated, mostly voluntary
Smooth muscle
Nonstriated, involuntary
Cardiac muscle
Striated, involuntary
Myofibers = muscle fibers = muscle cells
Formed from fusion of myoblasts
Existing muscle fibers hypertrophy
Sarcolemma
Plasma membrane of muscle cell
T tubules
Invaginations in membrane, allow action potentials to propogate
Sarcoplasmic reticulum
Fluid filled, stores calcium
Sarcoplasm
Cytoplasm of muscle cells, contains organelles
Myofibrils
Allow contraction, extend entire length of cell
Contractile component of myofibrils
ATP to mechanical
Myosin + actin filaments
Myosin
Thick filament
Actin
Thin filament, has myosin binding site
Regulatory component of myofibrils
Tropomyosin + troponin
Tropomyosin
Block `myosin binding site, prevents myosin from binding actin in relaxed muscle
Troponin
Holds tropomyosin in place, binds calcium
Structural component of myofibril
Sarcomere
Sarcomere
Functional unit
Sliding filament model
Filaments don’t shorten, they slide
Sarcomeres shorten
Muscle
Continuous connective tissue
Endomysium
Surrounds individual muscle cells
Perimysium
Surrounds fascicles, which are groups of muscle cells
Epimysium
Thick connective tissue, binds all fascicles together
Tendon
Connects muscle to bone
Tendons
Highly ordered collagen fibers
Poorly vascularized
Different shapes and sizes
Fascia
Bandage, wraps around of muscles
Isometric contraction
Contraction without a change in length
Isotonic contraction
Contraction with change in length
Concentric contraction
Muscle shortens
Eccentric contraction
Muscle lengthens
More likely to injure
Origin
Attachment to stationary bone (usually proximal or superior)
Insertion
Attachment to movable bone (usually distal or inferior)
Primer mover
Most force and movement
Synergist
Muscle that helps the prime mover
Antagonist
Muscle that opposes prime mover
Can relax or maintain some tension
Fixator
Prevents bone from moving, steadies