Muscle structure and function Flashcards
what do muscles do
produce movement, maintain mosture and positions, protection, heat production
what are the 3 types of muscles we have
smooth, skeletal, cardiac
how do muscles contract
muscles swell upon contraction
do muscles increase in volume
no in fact they do the opposite and decrease in volume by a small amount
what are muscle fibres
bundles of fasicles within muscles that individuallycontract generate tension
what are tendons
attach muscle to bone, forces generated by fibres are gathered in tendons and pulls the bone
what are muscle fibres optimised for
trade off between strength and speed based on needs
pennate muscles
stronger than parallel as more packed in same space and have a greater PCSA cross section
when external force = muscles force what happens
muscle length will stay the same - isometric
when external force > muscles force what happens
muscle can be lengthened - eccentric
when external force < muscles force what happens
muscle can be shortened - concentric
what are the layers of a muscle
muscle - muscle fibre - myofibril - sarcomeres
what does a sarcomere consist of
2 interdigrated myofilaments, actin and myosin
what are the binding sites in the sliding filament
where the myosin heads can attach to actin filaments
what are cross bridges
temporary mechanical bridges between actin binding sites and myosin heads
