front 1 Excitability | back 1 The ability to respond to a stimulus |
front 2 Conductivity | back 2 Electrical changes travel along the plasma membrane, opening voltage-gated channels |
front 3 Contractility | back 3 Contractile proteins within the muscle slide past one another (sliding filament) |
front 4 Elasticity | back 4 The ability of a muscle to return to its original length |
front 5 Extensibility | back 5 Lengthening of a muscle fiber |
front 6 Functions of Skeletal Muscle | back 6 Body movement, maintenance of posture, protection & support, regulating elimination of materials, & heat production |
front 7 Muscle Fiber | back 7 Muscle cell |
front 8 Fascicle | back 8 Group of bound muscle fibers |
front 9 Myofibril | back 9 Small tubules within the muscle fiber that contain the contractile unit (sarcomere) |
front 10 Functions of Connective Tissue | back 10 Protection, site for distribution of blood vessels & nerves, & attachment to the skeletal system |
front 11 Epimysium | back 11 Surrounds the whole muscle Dense irregular tissue |
front 12 Perimysium | back 12 Surrounds the fascicle, contains lots of blood vessels & nerves Dense irregular tissue |
front 13 Endomysium | back 13 Surrounds & electrically insulates each individual muscle fiber; contains reticular fibers to help bind together muscle fibers Areolar tissue |
front 14 Tendon | back 14 A thick cord-like structure formed by 3 layers of connective tissue; attaches muscle to bone |
front 15 Aponeurosis | back 15 A thin, flattened sheet of dense irregular tissue; connects two muscle bellies |
front 16 Myoblasts | back 16 Fuse together to form a single muscle fiber, leading to multiple nuclei in one cell |
front 17 Satellite Cells | back 17 Myoblasts that do not fuse but remain in the muscle tissue to repair damaged muscle tissue |
front 18 Sarcolemma | back 18 Specialized plasma membrane that can transmit electrical impulses |
front 19 T-Tubules | back 19 Deep invaginations of the sarcolemma that extend into the skeletal muscle fiber to stimulate the sarcoplasmic reticulum |
front 20 Sarcoplasmic Reticulum (SER) | back 20 Internal membrane complex that is similar to smooth ER |
front 21 Terminal Cisternae | back 21 Sacs at the end of the SER that store calcium |
front 22 Calcium Pumps | back 22 Move calcium into the SER |
front 23 Calcium Channels | back 23 Move calcium out of the SER |
front 24 Calmodulin & Calsequestrin | back 24 Proteins that bind with calcium in the SER |
front 25 Myofibrils | back 25 Long, cylindrical structures that extend the length of the muscle fiber; 80% of the skeletal muscle volume; composed of myofilaments |
front 26 Myofilaments | back 26 Contractile proteins that are bundled within the myofibrils |
front 27 Myosin | back 27 Thick myofilament; globular head & elongated tail |
front 28 Actin & ATP | back 28 Two binding sites on myosin globular head |
front 29 Actin | back 29 Thin myofilament; two protein strands twisted around each other |
front 30 F-Actin | back 30 Two strands twisted together |
front 31 G-Actin | back 31 The individual bead; contains the myosin binding site |
front 32 Tropomyosin | back 32 Regulatory protein that covers the myosin binding sites of actin until moved |
front 33 Troponin | back 33 Regulatory protein that binds with calcium to move tropomyosin off the myosin binding sites of actin |
front 34 Sarcomere | back 34 The contractile unit; repeating unites within the myofilaments |
front 35 Z Disc | back 35 Proteins that are positioned perpendicular to the myofilaments & serve as anchors for the thin filaments; separates one sarcomere from another |
front 36 I Bands | back 36 Extend in both directions of the Z disc; disappears during maximal contraction |
front 37 A Band | back 37 Central region that contains the entire thick filament; does not change shape during contraction |
front 38 H Zone | back 38 Most central portion of the A band; disappears during maximal contraction |
front 39 M Line | back 39 Thin transverse protein meshwork in the center of the H zone |
front 40 Connectin | back 40 Extends from the Z disc to the M line through the core of each thick filament |
front 41 Dystrophin | back 41 A complex protein that anchors myofibrils to other proteins with within the sarcolemma that extend to the endomysium |