Chapter 12 Study Questions 1. Group 1 should become experts on the structure of a sarcomere. 2. Group 2 should become experts on the sliding filament theory. 3. Group 3 should become experts on the contractile cycle of skeletal muscle. 4. Group 4 should become experts on excitation-contraction coupling. 5. Group 5 should become experts on summation and tetanus. 6. Group 6 should become experts on smooth muscle contraction.
7. What are the three types of muscle found in the human body? Where can you find each, and what does each do?
Cardiac – found in the heart
Smooth – internal organs and tubes, stomach, urinary bladder
Skeletal – attached to bones 8. What controls the contraction of the different types of muscle?
Autonomic innervations or spontaneously 9. Describe the arrangement of muscle fibers to make a muscle.
Cell membrane called sarcolemma and cytoplasm called sarcoplasm. Arranged with their long axes in parallel. Each fiber is sheath in connective tissue with groups of adjacent fibers bundled together in units called fascicles. 10. Define the terms sarcolemma, sarcoplasm, myofibrils, sarcoplasmic reticulum, terminal cisternae, t-tubules.
Sarcolemma is the cell membrane of a muscle fiber, sarcoplasm is the cytoplasm, myofibrils are highly organized bundles of contractile and elastic proteins that carry out the work of contraction, sarcoplasmic reticulum is a form of modified ER that wraps around each myofibril, terminal cisternae are enlarged regions at the ends of the tubules that concentrate and sequester Ca2+, and t-tubles are a branching network associated with terminal cisternae. 11. What is the function of t-tubules?
They rapidly move action potentials from the cell surface to the interior of the fiber. 12. What are the different proteins that make up a myofibril?
Contractile proteins: Myosin and actin, regulatory proteins: tropomyosin and troponin,