Flashcards in Skeletal Muscle Deck (19):
What are the three types of muscle give any alternative names
Where does skeletal muscle occur?
At skeletal joints
What is meant by the term antagonistic pairs?
One muscle must reflax for another to contract
Thin filaments are also known as?
Thick filaments are also known as?
What causes striation on skeletal muscle?
The arrangement of myosin and actin fibres
Describe cardiac muscle
Branched to ensure charge distribution
Contain intercolated disks
Describe smooth muscle
Slow to contract and slow to tire
Two layers of smooth muscle
Describe what happens at a neuromuscular junction
Action potential travels down the Motor neurone
Volatge gated Ca2+ channels open
Causes vesicles of acetylcholine to fuse to membrane
Acetylcholine diffuses out binds to receptors
Na+ channels open causes depolarisation
Wave of depolarisation travels down the T tubule to the sacrolemma
When a motor neurone branches and controls more than one muscle what is this called?
Describe slow twitch muscle and the conditions it requires
Less powerful but over a greater period of time
Requires aerobic respiration and therefore rich blood vessel supply and many mitochondria
Describe fast twich muscle and the condions it works in
More powerful but cant go for long periods pf time
Usually anerobic respiration
So needs many enzymes
What two filaments are present in a myofibril
Myosin and actin
The myosin head can bind to?
Describe the interrelationships between tropomyosin tropanin and actin
Tropomyosin hides actin binding sites. It also binds to tropnin
Troponin has binding sites if Ca2+ binds it changes shape
Uncovers the actin site by moving tropomyosin in this shape change
An action potential has arisen down t tubules, describe how this triggers a muscular response
Action potential reaches sarcoplasmic reticulum
Releases Ca2+ into the sarcoplasm
Ca2+ reaches troponin binding sites
Allows myosin and actin to bind
Allows sliding filament hypothesis
Describe the sliding filament hypothesis
ATP attaches to myosin head
ATP----> ADP + Pi
Moves myosin head back storing elastic potential energy
Myosin attches to actin sites
Power stroke occurs where myosin head snaps forward
ATP inputted causing myosin to detach
Shortens the sacromere
How are muscle contractions stopped?
Ca2+ ions are actively transported back into the sacroplasmic reticulum