MS System: Joints & Muscles Flashcards
Joint functions x3
- Facilitate growth
- Transmit forces
- Allow movement
Why do younger ppl have more joints
- Epiphyseal plate hasn’t fused, so more cartilage
Synarthroses
- & example
Immovable, fixed
- skull
Amphiarthroses
- & example
Slightly movable
- spinal column
Diarthroses
- & example
Very movable
- knee
Sutures
- type
- info
- example
- Fibrous joint
- Dense fibre network holds bones together
- Skull vault bones
Syndesmosis
- type
- info
- example
- Fibrous
- Fibrous membrane between bones
- Between radius & ulnar
Primary synchondrosis
- type
- info x2
- example
- Cartilaginous
- bone - hyaline - bone
- V strong, no movement
- 1st costosternal joint
Secondary synchondrosis
- type
- info x2
- example
- Cartilaginous
- bone - hyaline - fibrocartilage - hyaline - bone
- Midline of body, limited movement (amphiarthroses)
- Pubic symphysis, intervertebral disks
Synovial
- info x2
- Most common
- Friction-free movement
Soft tissue joint classification (3 types)
- Fibrous
- Cartilaginous
- Synovial
Features of a synovial joint x4
- Fibrous capsule
- Synovial membrane
- Articular cartilage
- Articular cavity/capsule
Fibrous capsule
- structure
- function x2
- Collagen fibres, rich nerve supply
- Gives structure, holds bones together
Fibrous capsule & ligaments….
Fibrous capsule can thicken along lines of stress –> ligaments
Why is nerve supply important in the fibrous capsule
Important for proprioception
body’s awareness of its position in space
Synovial membrane
- location
- structure
- function x2
- Inside of fibrous capsule
- Collagenous tissue
- Produces synovial fluid, lubricates joint
Articular cartilage
- location
- structure
- function
- Lines ends of bone
- Hyaline cartilage
- Friction-free surface
Problem w structure of articular cartilage
- Avascular (no blood vessels) –> poor blood supply –> poor at repairing itself
Synovial fluid
- functions x3
- Reduces friction
- Provides metabolites to articular cartilage
- Removes waste
Synovial fluid & viscosity
Can change physical property depending on force going through it
- relaxed movement –> low
- strong force –> thickens –> shock absorber
Range of movement determined by….
Shape of articular surface
e.g. ball & socket = 3 planes
Stability influenced by… x3
- Shape of bones
- Strength & position of ligaments
- Muscle tone (more = more stable)
Muscle tone
Continuous low-level pull within a muscle
Intra-articular discs
- what
- where
- function
- example
- Fibrocartilage disks
- Joints w rotatory movements
- ‘deepen’ the joint –> more stable
- Knee
Gomphosis
- type
- info
- example
- Fibrous
- ‘peg & socket’
- Teeth in jaw
Components in muscle functional groups x3
- Prime mover –> main participant
- Synergists –> other muscles = assist
- Antagonists –> group that opposes movement
Deep fascia
- types x3
- at end of muscle fibre…
- Endomysium (round 1 fascicle/muscle fibre)
- Perimysium (round fascicles)
- Epimysium (dense sheath on surface)
- –
- All come together –> tendon
Myostatin
- what
- if defective…
- Inhibits differentiation of skeletal muscle
- Loses inhibition of muscle cell growth
Ligament function
Restrict movement, protects joint
Intrinsic ligament
Part of capsule
Extrinsic ligament
Outside of capsule (e.g. knee)
Sprain
Overstretching of a ligament
Bursae
- what
- where
- function
- example
- Sacs lined w synovial membrane (therefore, lubricated w synovial fluid)
- Where friction occurs (e.g. between skin & bone)
- Prevent rubbing
- e.g. in knee
Synovial sheaths
- what
- where
- why
- example
- problem
- Specialised bursae
- Surround tendons subject to pressure
- Prevent rubbing (in long tendons)
- e.g. in hand (finger to wrist)
- Are routes for infection - as are long
Osteoarthritis
- type of disease
- where
- what
- degenerative (due to excess use)
- weight-bearing joints
- extra bone growth –> loss of joint space
Rheumatoid arthritis
- type of disease
- where
- what
- autoimmune
- any joint
- antibodies attack synovial membrane –> destroys articular cartilage
