Muscles

Question 1

Tetanic contraction

Answer 1

uninterrupted muscular contraction caused by high-frequency motor impulses

Question 2

Diaphragm

Answer 2

dome-shaped muscle separating the thoracic and abdominal cavities in mammals


Question 3

fibrillation

Answer 3

asynchronous, disorganized contraction of muscle fibers in the atria or ventricles of the heart


Question 4

functional syncytium

Answer 4

heart muscle cells which (in contrast to skeletal muscle cells) form a functional unit because of the gap junctions between them

Question 5

isometric contraction

Answer 5

contraction of muscles only when tension changes

Question 6

Purkinje fibers

Answer 6

heart muscle fibers conducting excitation from the bundle of His to the myocardium of the ventricles


Question 7

sarcolemma

Answer 7

membrane of the muscle fiber

Question 8

sarcoplasm

Answer 8

cytoplasm of the muscle fiber

Question 9

T-tubules

Answer 9

invagination of the sarcolemma - carrying excitation to the sarcoplasmic reticulum


Question 10

sarcoplasmic reticulum

Answer 10

similar to smooth endoplasmic reticulum - have large internal store of Ca+ ions in the muscle fibers

Question 11

myofibril

Answer 11

a longitudinal unit of a muscle fiber, made up of sarcomeres and surrounded by sarcoplasmic reticulum

Question 12

sarcomere

Answer 12

between two z lines in the myofibril

Question 13

systole

Answer 13

the portion of the heart beat when the heart muscle is contracting


Question 14

sliding filament hypothesis

Answer 14

theory explaining muscle contraction by sliding of actin and myosin filaments on each other


Question 15

muscle twitch

Answer 15

contraction and relaxation caused by a single action potential in the muscle