B4: types of muscle

Question 1

skeletal muscle

Answer 1

responsible for voluntary movement. innervated by somatic nervous system. striated and multinucleated.

Question 2

contractile velocity

Answer 2

how rapidly fibers are capable of contracting

Question 3

slow-twitch fibers

Answer 3

aka red fibers due to myoglobin (O2 carrier). slower to fatigue

Question 4

fast-twitch fibers

Answer 4

aka white fibers. high contractile velocity but tire quickly

Question 5

oxygen debt

Answer 5

disparity between how much oxygen muscles require to produce ATP and how much is actually provided through breathing

Question 6

sarcomere

Answer 6

unit of skeletal muscle. made of thick and thin filaments

Question 7

thick filaments

Answer 7

composed of myosin

Question 8

thin filaments

Answer 8

composed of actin

Question 9

troponin and tropomyosin

Answer 9

attach to actin

Question 10

sarcoplasmic reticulum

Answer 10

membranous organelle that contains high conc. of Ca2+

Question 11

smooth muscle

Answer 11

involuntary and controlled by autonomic nervous system. not striated and contain only one nucleus.

Question 12

cardiac muscle

Answer 12

unique to the heart. striated, involuntary, contains only one nucleus. separated into intercalated discs

Question 13

intercalated discs

Answer 13

contain many gap junctions which allow for ions to flow rapidly and APs to be propagated quickly

Question 14

myogenic activity

Answer 14

electrical activity independent of the brain that regulates the heart’s rhythm

Question 15

purkinje fibers

Answer 15

branching fibers in walls around ventricles that induce cardiac muscle contraction