Intro to MSK Flashcards
Define MSK system
Anatomical structures that allow locomotion
What has the MSK system evolved to allow us to do?
Find food or shelter
Escape predators or threats
Look after children
Use tools or weapons
What is a joint?
Where 2 bones meet
What are tendons?
cords of strong fibrous connective tissue attaching muscle to bone
What are ligaments?
sheets of fibrous connective tissue which connect two bones
How many bones does an adult have?
206 + sesamoids (bones embedded in tendons or muscles)
How many bones does a child have?
270
What is included in the appendicular skeleton?
pectoral and pelvic girdle, limbs
What is included in the axial skeleton?
cranium, vertebral column, rib cage
What are the 5 functions of the skeleton?
- Rigidity/support
- Movement
- Protection for internal organs (e.g. skull, rib cage)
- Mineral storage/homeostasis (e.g. regulation of calcium and phosphate)
- Bone marrow produces blood cells
What 2 things is bone composed of?
Cells and ECM
What is the organic component of ECM in bone?
Osteoid
What is the inorganic component of ECM in bone?
Minerals
Name the 4 cells in bone
Osteogenic cells
Osteocytes
Osteoblasts
Osteoclasts
What are osteogenic cells?
Bone stem cells
What are osteoblasts?
Bone forming cells
What do osteoblasts secrete?
Osteoid
What do osteoblasts catalyse?
Mineralisation of osteoid
What are osteocytes?
Mature bone cells
Hpw are osteocytes formed?
When an osteoblast becomes embedded in its own secretions
What do osteocytes do?
Sense mechanical strain to direct osteoclast and osteoblast activity
What are osteoclasts?
‘Bone breaking’ cells
Where are osteoclasts derive from?
Bone marrow
What do osteoclasts do?
Dissolve and resorb bone by phagocytosis
What dictates bone mineral density (BMD)?
Balance between osteoblast and osteoclast activity
What are the 3 mechanisms of bone fracture?
Trauma
Stress
Pathological
What are the 2 types of traumatic fractures?
Low energy and high energy
What causes a stress fracture?
Abnormal stresses on normal bone
What causes a pathological fracture?
Normal stresses on abnormal bone
What are disease of the joints called?
Arthritis
What are fibrous joints?
Joints with no space between the bones
What is an example of a fibrous joint?
Sutures in the skull
What movement classification are fibrous joints?
Synarthroses (generally allow no movement)
What are cartilaginous joints?
Joints in which the bones are connected by cartilage
What is an example of a cartilaginous joint?
Joints between spinal vertebrae
What movement classification are cartilaginous joints?
Amphiarthroses (allow very limited movement)
What are synovial joints?
Joints that have a space between adjoining bones (synovial cavity) that is filled with synovial fluid
What movement classification are synovial joints?
Diarthroses ( allow for free movement of the joint?
What are the 4 types of synovial joints?
Hinge joints
Ball and socket joints
Pivot joints
Condyloid joints
Name a hinge joint
Knee
Name a ball and socket joint
Shoulder
Name a pivot joint
Cervical spine
Name a condyloid joint
Wrist
What sort of movement do hinge joints have?
Monoplanar
What sort of movement do ball and socket joints have?
Multiplanar
What sort of movement do pivot joints have?
Allow limited rotating movement
What sort of movement do condyloid joints have?
Allow all types of movement except pivotal movements
What does the synovium contain?
1-3 cell deep lining containing macrophage-like phagocytic cells and fibroblast-like cells
Type 1 collagen
What is synovial fluid?
Hyaluronic acid-rich viscous fluid
What does articular cartilage contain?
Type II collagen
Proteoglycan (aggrecan)
What is cartilage composed of?
1) specialized cells (chondrocytes)
2) extracellular matrix: water, collagen and proteoglycans
(mainly aggrecan)
What is the purpose of cartilage?
To provide a smooth lining at a joint to allow the ends of two bones to move with minimal friction
Does cartilage have a blood supply?
No, it is avascular
What are the 2 types of arthritis?
Osteoarthritis
Inflammation associated arthritis
What causes osteoarthritis?
Loss of cartilage- it is degenerative
What are the 3 types of inflammation associated arthritis?
Autoimmune A
Crystal A-
Septic A-
What is autoimmune arthritis?
Where the immune system attacks the body
What is an example of autoimmune arthritis?
Rheumatoid arthritis
What is crystal arthritis?
Where crystals trigger inflammation
What crystals cause gout?
Urate
What crystals cause pseudogout?
Calcium pyrophosphate dihydrate (CPPD)
What is septic arthritis?
Bacterial infection in the joint
How is osteoarthritis affected by movement?
Gets worse with movement
How is rheumatoid arthritis affected by movement?
Worsens with inactivity
What type of arthritis causes prolonged morning stiffness?
Rheumatoid
What are the speeds of onset for the 4 types of arthritis?
Osteoarthritis: slow (months -> years)
Autoimmune: subacute (usually weeks -> months)
Septic arthritis: rapid (hours)
Crystal arthritis: rapid (hours)
What are muscle pairs called?
agonists/antagonists
What do ligaments and tendons consist of?
Mostly type 1 collagen
What do ligaments connect?
Bone to bone
What do tendons connect?
Muscle to bone
What is the role of ligaments?
Restrict joint motion
Stability and proprioception
What is the role of tendons?
Transmit forces
What are tendons made up of?
Collagen fibrils
What causes an acute tendon pathology?
Force exceeds tensile strength
What causes chronic tendon pathology?
Pathological response to poor biomechanics or overuse
What is frequently observed in tendinopathy?
Disordered collagen fibres
Neovascularisation
