musculoskeletal system Flashcards
3 major components of the musculoskeletal system and from where they are derived
bone, connective tissue and skeletal muscle all derived from the mesoderm
functions of the bone
support, protect e.g thorax protects the lungs, metabolic e.g strokes ca2+ and phosphate, movement and heamatopoiesis
functions of skeletal muscle
locomotion, posture metabolic (store of glycogen), venous return especially in lower veins where low pressure, cheat production (shivering) and continence (sphincters)
functions of the connective tissue
tendon- muscle to bone force transmission
ligament- support bone-bone
fascia- very tough, protects and compartmentalises
cartilage- prevents fictions acts, as shock absorber
(synovial membrane)- lubricates by secreting fluid
(bursa)- synovial fluid scar to protect tendons from friction
composition of bone
osteoblasts, casts and cites. some fibroblasts, macrophages, mast cells and adipocytes.fibre include collagen and elastin. ground substance with water and GAG/PG. calcium and phosphate give it compressive strength and collagen fibre gives it tensile strength
what happens if the balance of the action of osteoblast ad clasts is disrupted
causes disease. the levels are controlled in the blood and more calcium and phosphate can be excrted if needed
types of bone and their function + examples
irregular(skull), sesamoid (protect from friction in patella), long(levers e.g femur), short(range of movement in wrist) and flat(protection e.g skull)
name some surface features of bones
bones have prominences which bones can attach to, the larger the prominence the more powerful the muscle attached. also have groves, notches feraminas(holes) and nutrient feraminas found on the surface where blood vessels and nerves are found
how is the bone supplied with blood
via nutrient artery and blood supplies at epiphyses.
what happens when fracture before blood supplies at epiphyses and nutrient artery are connected
can lead to avascular necrosis (only in children)
how is bone deposition regulated
increased/ decreased depending on how much its used. osteocytes detect force passing through bone and communicate with osetoblasts/calsts to increase or their activity
what are joints
connect bone to bone and their role Is to maximise stability and keep range of movement
what are the 3 types of joints +draw diagram of one
fibrous- highly stable, glued by collagen and found in voucher between skull. movement v limited
cartilaginous- held by cartilage, movement limited
synovial- with synovial, highly mobile and found everywhere
types of synovial joint
plane- sliding of 1 bone over another
hinge- flexes and extends like door
pivot- movement around 1 axis
saddle- movement in oval shape, hinge+side to side (thumb)
condyloid- movement around 2 axes (wrist)
ball and socket- around multiple axes e.g hip
development of synovial joint
kill chondrocytes at site of joint. space (joint cavity) formed. synovial joint is an interception in cartilage. perichondrium is constant with joint capsule
types of levers and draw them
first class - like seesaw e.g neck
second class- like wheel barrow e.g standing on tiptoes
third class- like forceps e.g biceps
what is the origin of a muscle
stationary anchor point for muscle, sits proximally
what is the point of insertion of a muscle
mobile/distal attachment
types of movements of muscles
they only pull, they don’t push and they always work together
types of muscle contraction
concentric contraction- pulls and shortens
eccentric contraction- pulls and lengthens e.g lowering weight
isometric contraction- muscle pulls while staying the same length e.g carrying box
muscles never push
where are muscles found?
they are found in fascial compartments and within they share common function e.g have same nerve
types of muscles and the differences. +draw
parallel, fusiform, circular, triangular and pennate(feather shaped). pennate are found in calf and exert much more force than parallel because they can pack many more fibres into their structures for greater power but can’t shorten as much as parallel muscle
what is the tendon (connective tissue)
connects muscle to bone = dense regular tissue
what are ligaments (connective tissue)
connect bone to bone. are pretty much thickened areas of joint capsule. many ligaments found in knee
what are aponeurosis (connective tissue)
flattened tendons that connect muscle to muscle e.g in skull
what are fascia
compartments of muscle in which muscles have similar action, same innervation and a similar blood supply
what is hiltons law
nerve is sensitive to skin , muscle and joint that it crosses. controls it all
what are hox genes
they determine different types of vertebrae that form in each body segment and which limbs will come from each limb bud
what are homeotic mutations
mutations that causes tissues to alter their normal differentiation producing structure in unusual locations e.g production of an extra lumbar or 6 toes
explain limb development
limbs develop from limbs buds formation of an apical ectodermal ridge (promotes growth of limbs) by ectodermal cells and then elongates through the proliferation of mesenchyme. then bones develop by ossification. the libs then rate in opposite directions.
