joints, muscles and sliding filament theory Flashcards
what are tendons
they attach muscle to bone
if they were elastic the force of the musuclar contraction wouldn’t be exerted
what are ligaments
attach bone to bone
they have to be strong to hold the bones in the correct way
describe the collagen fibre formation
hydrogen bonds between chains create cross links to form a collagen molecule
why is rest and physiotherpay needed after surgery?
rest: tissue needs time to repair
physio: tendos are relatively inelastic comapred to the ligaments
they need to be stretched out so that full range of movement can across the joint
describe the functionantagonistic muscle pairs
a pair of muslces that work in opposite directions
e.g. whilst one contracts, the other relaxes
why does someone suffering from arthritis complain of severe pain in the joints?
reduce cartilage meaning there is less cushioning on the bones, so there is mroe friction
leads to the local inflammatory response - swelling
describe the difference between a flexor and an extensor
flexor: when contracted this the muscle that bends the joint
extensor: when contracted this is the msucle that straightens the joint
properties of slow twitch (e.g. distant cyclists)
fatigue resistance - limited lactic acid builds up
myoglobin - increase the concentration of oxygen
little sarcoplasmic reticulum - muscle contractions need to be slow and prolonged
low glycogen content - good blood supply, the muscle tissues has an adequate supply of glucose
what is myoglobin?
it is similar to haemoglobin as it has high affinity, it is found in the muscle cells acts as an oxygen store
properties of fast twitch (e.g. sprinter)
high glycogen content - poor blood supply, the muscle tissues do not have an adequate supply of glucose
little myglobin - anaerobic respiration takes place in the absense of oxygen
extensive sacroplasmic reticulum
fatique quickly - high level of anaerobic respiration so lactic acid builds up
what is the sarcoplasmic reticulum?
series of membrane bound sacs that store and release calcium ions required for muscle contractions
stages of muscular contraction
calcium ions attach to tropin molecule
tropin moves and myosin binding site exposed causing myosin to bind to actin and form an actomyosin cross bridge
ADP and Pi are released from myosin head causing it to bend - moves actin causing the sacromere to shorten
ATP attaches to myosin causing the cross bridge to break - myosin detaches from actin
ATP is hydrolysed - ADP and Pi are formed
myosin head changes shape and returns to original position
