| Question |
Answer |
| Skeletal muscle | striated, voluntary |
| Smooth muscle | non-striated, involuntary, single/ multiunit |
| Cardiac muscle | striated, involuntary, autorhythmicity |
| Basic functions of muscle | movement, maintain posture, heat generation |
| Characteristics of muscle | excitability, contract-ability, extensibility, elasticity |
| Sarcolemma | plasma membrane with t-tubules |
| Sarcoplasm | cytoplasm of muscle cell |
| Sarcoplasmic reticulum | smooth er, calcium ion storehouse |
| Myofibrils | organized proteins responsible for contraction |
| Myofilaments | cytoskeleton |
| I band | light band, thin filaments, myosin |
| A band | dark band, thick filaments, actin |
| Z line | middle |
| H band | center area |
| Myosin properties needed for contraction | -ATP site closely associated with actin binding site
-Position of the myosin
-release of ADP, so muscle can relax & new ATP can bind |
| Troponin- Tropomyosin complex | serve as a switch for muscle contraction and muscle relaxation
tropomyosin must be moved for myosin cross bridges to attach actin- requires ca++ |
| Motor unit | a lower motor neuron & all of the skeletal muscle fibers stimulated by branches of its axon, larger units= more force, smaller units= finer degree of neural control |
| Muscle twitch | occurs when muscle is stimulated with a single electric shock, a quick contraction then relaxation |
| Latent period | time stimulus is applied until contraction begins |
| Contraction | beginning of contraction to peak |
| Relaxation | peak to end of contraction |
| All or none | a given response will be produced to its maximum extent in response to any stimulus equal to or greater than threshold response
ex- action potential to twitch |
| Temporal summation | asynchronous contraction, twitches alternate to produce a continuous maintenance of force |
| Spatial summation | recruitment, more cells = more force |
| Elastic components function | smooth out muscle behavior, absorbs some of the tension as a muscle contracts, elastic recoil help muscle return to resting length |
| slow twitch | small, rich in myoglobin (oxygen), sustain aerobic |
| fast twitch | larger, lots of thick & thin, low myoglobin (oxygen), less blood flow, fast to fatigue |
| Golgi tendon organs | can stop a muscle contraction, protective device, senses the tension muscle exerts on its tendons |
| Muscle spindles | senses muscle length, muscle that require the finest degree of control have the most
extrafusal: insert into tendons on each side
intrafusal: several thin muscle cells in connectrive tissue sheath |
| Final common pathway | motor pathway, consisting of the motor neurons by which nerve impulses from many central sources pass to a muscle |
| Smooth muscle cells | filaments in a spiraling pattern, no striations, can stretch greatly, big active range, gap junctions |
| single unit/ multiple unit | single: cells work as a collective group, lots of gap junctions
multiple: each cell functions independently, few gap junctions ex- eye |
Science Vocab 147928
