muscle structure and contraction Flashcards
type of muscle found attached to bones/ skeleton. allows movement of the skeleton at the joint
skeletal
type of muscle tissue that is found in the digestive system, reproductive tracts, vascular system, bladder and bowls
smooth
type of muscle that makes up the heart. it’s myogenic- can contract without nervous input
cardiac
the name of the process where muscle tissue is developed
myogenesis
fibres are surrounded by the ____________
sarcolemma
around each myofibril is a network of tubes called the ___________ ___________
sarcoplasmic reticulum
holes in the sarcolemma open into ____________ which meet the sarcoplasmic reticulum
T-tubules
found on the actin filament and is a thin protein that lies within a groove between actin molecules
tropomyosin
found in the actin filament and is a globular protein that binds to the actin chains at regular intervals
troponin
found in the actin filament and is a globular protein that binds to the actin chains at regular intervals
troponin
found along the myosin filament and attach to actin
myosin heads
1st stage of contraction
a nervous impulse arrives at the neuromuscular junction
2nd stage of contraction
acetylcholine is released in the gap between the neurone and the sarcolemma and the signal goes through T-tubules
3rd stage of contraction
sarcoplasmic reticulum released calcium ions over the myofibrils
4th stage of contraction
ca+ binds to troponin changing the shape of the tropomyosin revealing binding sites
5th stage of contraction
myosin heads are free to attach to the actin forming a cross bridge
6th stage of contraction
the heads tilts towards the centre pulling the actin filaments inwards slightly and ADO and Pi are released
7th stage of contraction
ATP molecule attaches to myosin and is hydrolysed. it’s released energy which breaks the cross bridge
8th stage of contraction
head moves back to original state
what does ATP stand for
adenosine triphosphate
what does ADP stand for
adenosine diphosphate
what are the segments that make up myofibrils called
sarcomeres
what is the name of the thin protein filament
actin
what causes calcium to be released in the first stage
a nervous impulse causes acetylcholine to be released which causes the sarcoplasmic reticulum to release calcium
what protein changes shape to reveal binding sites
tropomyosin
what is the power stroke
myosin head tilts and pulled the actin. ATP causes it to let go
