fast and slow twitch fibres+ myofibril labelled

Question 1

what is the structure of slow twitch fibres?

Answer 1

-large store of myoglobin
-rich blood supply
-many mitochondria

Question 2

what is the structure of fast twitch fibres?

Answer 2

-thicker
-more myosin filaments
-large store of glycogen and phosphocreatine
-high conc of enzymes for anaerobic resp

Question 3

where are slow twitch fibres found?

Answer 3

in the calf muscles

Question 4

where are fast twitch fibres found?

Answer 4

in the biceps

Question 5

some characteristics of slow twitch fibres?

Answer 5

-contract slower
-respire aerobically for long periods of time, due to rich blood supply and myoglobin oxygen store
-adapted for endurance

Question 6

some characteristics of fast twitch fibres?

Answer 6

-contract faster to provide short burst of powerful contraction
-intense exercise

Question 7

what do thick/ thin myofilamnets represent?

Answer 7

-thicker bands=myosin
-thinner bands=actin

Question 8

what is the A band?

Answer 8

• thick and actin overlap, dark band

Question 9

whats the I band?

Answer 9

-thin actin filaments only, lighter bands

Question 10

what are the ends of sarcomer called?

Answer 10

-z line

Question 11

whats the middle of sarcomere called?

Answer 11

-M line

Question 12

whats around the m line called, that only contains myosin?

Answer 12

-H zone