Muscle Systems

Question 1

how do muscles contract

Answer 1

Skeletal, Cardiac, Smooth muscles all use sliding filament contractile mechanism

Question 2

muscle fibers

Answer 2

are large and multinucleated; formed from the fusion of embryonic
myoblasts. Each muscle consists of many muscle fibers bundled together by connective
tissue.

Question 3

muscles

Answer 3

attached to the skeleton via connective tissue called tendons

Question 4

two types of skeletal muscle

Answer 4

slow twitch and fast twitch

Question 5

sarcomeres

Answer 5

units of contraction

Question 6

skeletal muscle

Answer 6

made up of bundles of muscle fibers

Question 7

myofibrils

Answer 7

highly ordered assemblages of thick myosin and thin actin filaments

Question 8

steps of muscle contraction

Answer 8

Motor nerve action potential arrives at the motor end plate

• Acetylcholine released, sarcolemma and membranes depoloarized
• Action potential transmitted via T-tubules to sarcoplasmic reticulum
• Ca2+ release from SR terminal cisternae into sarcoplasm
• Ca2+ bound by troponin
• Tropomyosin shift from actin binding site and actin-myosin cross bridge formation
• Myosin ATPase activated and ATP hydrolyzed

Question 9

for contraction, muscle requires

Answer 9

energy

Question 10

Muscles have three systems for supplying ATP for contractions

Answer 10

immediate system: uses preformed ATP and creatine phosphate

glycolytic system: metabolizes carbohydrates to lactic acid and pyruvate

oxidative systm: metabolizes carbohydrates or fats to H2O and Co2

Question 11

creatine

Answer 11

a supplement that helps espcially sprnters

Question 12

glycolytic system

Answer 12

glycolysis: faster process that supplies ATP

Question 13

oxidative system

Answer 13

ETC + Krebs/oxidative phosphorylatoion

slower process that supplies ATP