Flashcards in Muscles Deck (21)
describe antagonistic pairs
muscles are in antagonistic pairs in an incompressable skeleton, thet can only pull - in order for a limb to move in both directions there are 2 muscles
what is a ligament?
attaches bone to bone
what is a tendon?
attaches bones to muscles
what does antagonist describe?
what does agonist describe?
what are the 5 features of skeletal muscle?
lots of mitochondria, long cells called muscle fibres, multitnucleate, contain myofibrils, contain myofilaments (actin and myosin)
what region is the sarcomere?
between the z lines
what is the A band?
what is the I band
what is the H zone?
non overlapped myosin
thin and light
dark and thick
in a relaxed muscle what prevents an actinomyosin bridge forming?
what is the role of Ca2+ in muscle contraction?
Ca2+ causes tropomyosin to move out of binding site, allowing actinomyosin bridge to form. Also actrivates ATP ase for the hydrolysis of ATP
what is the role of ATP in contracting muscles?
changes the shape of the myosin heads, continues as long as binding site is open, detaches the myosin head and returns to starting position. ATP also needed to reabsorb calcium ions.
when a sarcomere contracts…
the H, I and sarcomere get smaller. The A band stays the sAme
describe the phosphocreatine reaction.
PCr + ADP ---> ATP + Cr - this reaction is short and quick, reserves used up quickly, anaerobic and alactic
the enzyme creatine kinase removes the phosphate from the PCr, allowing phosphorylation to take place
describe anaerobic respiration
glycolysis - 2 ATP made, pyruvate -----> lactate - causes muscle fatigue
describe aerobic respiration
lots of ATP made by oxidative phosphorylation, slow, no harmful waste
describe fast twitch muscles
contract/relax quickly, high force of contraction, fatigue quickly, anaerobic respiration, few… mitochondria, blood vessels, myoglobin ….. So appear white/ pale