Basic Concepts Flashcards
Name the components of MSK (3)
- Bones
- Muscle
- Connective tissue
Functions of bone (6)
- Support - posture
- Protection ie skull and ribs
- Metabolic - homeostasis of calcium and phosphate
- Storage - bone marrow stores fat
- Movement - bones act as leavers which muscles attach to and contract to pull the bone
- Haemopoesis - extensively throughout skeleton in infants, axial skeleton in adults
Functions of muscle (6)
- Locomotion (movement)
- Posture
- Metabolic (muscles store glycogen)
- Venous return (The muscles in the leg compress deep veins and help to propel venous blood back up towards the heart
- Heat production (shivering)
- Continence (pelvic floor muscles prevent urine and faeces escaping inappropriately)
Connective tissue function (6)
Tendons - connect bone to muscle
Ligament - bone to bone
Fascia - compartmentalise muscle, protect
Cartilage - articular (decrease friction) fibrocartilage (shock absorption, help bones fit together)
Synovial membrane - secretes synovial fluid for joint and tendon lubrication to help the joint move freely
Bursa - synovial fluid filled sac (protect tendons, ligaments from friction)
Bone surface features
Large prominences = powerful muscle will attach
Grooves - nerves
Notches (holes) - blood vessels
Foramina - holes to allow blood to enter
Blood supply to bone
Diaphysis supplied by nutrient artery
Periosteum supplied by periosteal artery
Metaphysical arteries supply top
BONES DIE if not supplied with blood - important in fractures in femur
Classification of joints
Fibrous, cartilaginous, synovial
Fibrous joints
Collagen fibre joining bone
Limited mobility
Found where you need stability and strength - tooth socket, sutures skull
Cartilaginous joints
Cartilage acts as glue
Limited mobility
Found at ends of growing bones, midline of adults
Synovial joints
Capped by smooth articular (hyaline) cartilage
Synovial fluid separating
Highly mobile
Synovial membrane and fibrous cartilage membrane surrounds*
*continuous with periosteum
Primary cartilaginous joints
Epiphyseal joints
Secondary cartilaginous joints
Pubic symphysis
Types of joint
Plane, hinge, pivot (pin in hole), saddle, condyloid (2 oval, no rotation), ball and socket
Synovial joint development
Joints form within cartilage model
Cell death within cartilage
Gap = synovial joint
Some cartilage may be left for ligaments
Class of levers
First class - scissors (effort one end, fulcrum centre, load end)
Second class - wheelbarrow (effort, load, fulcrum)
Third class - forceps (fulcrum, effort, load)
Class of levers examples
First class - head on neck
Second class - standing on tip toes
Third class - holding arm out
Origin point muscle
Stationary, proximal anchor point
Insertion point muscle
Mobile, distal attachment point
Muscle concepts
Contraction symmetrical (equal force on origin and insertion)
Muscles can only pull
Can only act on joints they cross
Muscles work together
Type of contraction
Concentric - muscle shortens and pulls
Eccentric - muscle pulls while lengthening
Isometric - muscle pulls without changing length
Facial compartments
Muscles are found within, share common innervation ad action
Types of muscle
Parallel, fusiform, circular, trianglular, pennate (uni, bi, multi)
How are skin creases created
Adhesion of skin to underlying fascia
Tendon
Dense regular connective tissue, muscle to bone, poor blood supply
Ligament
Dense regular CT, created by thickening of fibrous capsule, stop dislocation(limit movement), maintain arch of foot
Aponeurosis
Sheet like tendons
Plantar fascia in foot - maintain arch
Each fascia compartment has
Similar action, innervation, blood supply and nerve supply
Innervation of joints (Hilton law)
Nerve that supplies muscle, which acts on a joint, is sensory to that joint and sensory to the skin overlying that muscle insertion
How is the body segmented
Craniocaudal axis - Hox genes (postcode for body)
Limb rotation in development
Upper limbs rotate OUT 90 degrees
Lower limbs rotate IN 90 degrees
