General Musculoskeletal System Flashcards
Long Bone
- Resists gravity so we can stand
- Middle section = diaphysis
- End section = epithysis
- epithysis - diaphysis - epithysis
Flat Bone
- Protects vital organs to maintain life
- Large SA for site of muscle attachment
- Source of red bone marrow (usually from hip - safest & most accessible)
- The whole bone isn’t completely flat - just the majority
Short Bone
- Equal width & length
- For stability but has limited movement
Irregular Bone
- Doesn’t fit into other bone classifications
Sesamoid Bone
- Seed shape
- Forms within tendons
Fibrous Joint
- Dense, fibrous connective tissue between bones - rich in collegen
- Found in teeth, syndemosis (fib+tib joint) & sutures (front skull)
- Synarthrosis - gives limited/no movement
Primary Cartilaginous Joint
- Hyaline cartilage
- Bone - hyaline cartilage - bone
- Example - first sternocostal rib
- Amphiathrosis - permits slight mobility
Secondary Cartilaginous Joint
- Thin layer of hyaline cartilage & fibrocartilage
- Bone - hyaline - fibrocartilage - hyaline - bone
- Example - intervertebral disc
- Amphiathrosis - permits slight mobility
Synovial Joints
- Ends of bone lined with cartilage to resist compression
- Space between = synovial cavity filled with synovial fluid
- Diathrosis - freely moveable
Clinical Relevance - Synovial Joints
- Osteoarthritis - space breaks down & joints rub (painful)
- Rheumatoid arthritis - inflamation
Ligaments
A fibrous, connective tissue that connects two bones
- mechanical stability of bones
- guides joint motion
- prevents excess movement
Ligament Types
- Capsular - direct connection to the bone/joint
- Extracapsular - lie outside the capsule
- Intracapsular - lie within the capsule
Bursae
Synovial fluid-filled sacs (lubricated cushions) that reduce friction when muscles & tendons rub over skin & bone, to ensure they can glide easily.
- Synovial - between bones & muscles, tendons & ligaments
- Superficial - located just underneath the skin, between skin & bone
- Adventitious/accidental - caused by repeat irritation (e.g big toe when shoe rubs)
Bursae Composition
- Sac is made from synovial membrane - typically thin, one cell thick
- Synovial fluid is secreted from the inner membrane of synovial joint into the synovial cavity
- Synovial fluid is ultrafiltrate from blood plasma & cells from joint tissue
Clinical Relevance - Bursitis
- A painful condition where the bursa become inflammed
- Appears red & tender, sore to touch and warm
- Can be treated by rest, elevatation & cold compress (minor) or antibiotics, steroid injections & removal (severe)
Skeleton
Axil Skeleton
- skull, vertabral column, ribs & sternum
- midline of body: protection & muscle attachment
Appendicular
- upper limbs: dexterity
- lower limbs: support & movement (locomotion - getting to to a destination)
- Arms & legs follow a similar pattern, evolutionary development as we used to be quadrapeds girdle > long proximal > two parallel long > short > long
Muscles
Muscle belly: contains contractile muscle fibres that generate force
- Usually run from one bone to another, across a joint
- During contraction, the muscle moves one bone to another
Stationary bone - origin
Mobile bone - insertion
- Muscles work in groups & have identifiable functions in generating movement (common action)
Agonist/prime mover - generates basic movement
Antagonist - controls movement
- Common innervation - group of muscles are usually supplied by the same nerve
- Creates ‘muscle memory’
Clinical Relevance - Neurological Examination (muscles & nerves)
Movement tests (neurological examinations) can tell if muscles & nerves are working simultaneously and that the spinal chord is intact
Tendons
- Tough bands of fibrous, connect tissue that usually connects muscle to bone (found at the end of muscles)
- Function: transfer muscle force to bone to facilitate joint movement
- Can be broad & flat (back) aka aponeuroses or rounded (ankle)
Clinical Relevance - Tendon Reflex
A clinical examination testing the stretch reflex of a tendon (shows intactness of the nervous system). The stretch is created by a blow apon a muscle tendon (e.g knee).
Clinical Relevance - Presentation of a Clavical Fracture
- Arm is adducted
- Lateral end depressed
- Tenting of the skin - medial end pulling
(presentation of fractures always depend on the pull of muscles attached)
Muscle Contractions
- Concentric contractions - get smaller
- Eccentric contractions - get longer
- Isotonic contractions - stay the same
A combination of contractions gives smooth/controlled movement, often against gravity
Superficial Fascia
Fasciae - layers of tissue made from collegen (connective tissue), lying deep to the skin. Found all over body but varies in people & parts - anatomical variation.
- Superficial fascia - outermost layer, a mixture of loose connective tissue & fat
- Thick layer for support & insulation
Deep Fascia
- Inner to superficial fascia, membraneous layer of connective tissue
- Seperates & surrounds groups of muscle - forms layers that may direct infection via specific parts
- Divides the body into compartments - fascial septa (usually containing muscle, nerves & vessels)
- Compartments show innervation (nerve supply) to muscles within them - usually common innervation
