Across
- 3. brief contraction of muscle fibers resulting from each action potential
- 4. fluid, fills entire joint capsule
- 6. connective tissue surrounding each muscle fiber
- 9. protein situated at regular intervals along the actin filament that has a high affinity for calcium ions
- 17. fiber’s membrane
- 18. cytoplasm of a muscle fiber
- 22. transverse tubules; run perpendicular to the SR and terminate in the Z-line between two vesicles
- 23. specialized sensory receptors located within joints, muscles, and tendons
- 25. fibers, modified fibers that run parallel to the normal
- 28. sense, conscious appreciation of the position of body parts with respect to gravity
- 31. when stimuli is delivered at so high a frequency that the twitches begin to merge and eventually completely fuse
- 33. joints, operate as hinges, rotating about only one axis (elbow)
- 34. thin myofilament (~ 6 nm in diameter) consist of two strands arranged in a double helix
- 36. thick myofilament (~16 nm in diameter)
- 38. junction, the junction between a motor neuron and muscle fibers it innervates (also called motor end plate)
- 39. pattern of a T-tubule spaced between two SR vesicles
- 40. found at both ends of the sarcomere and are where actin filaments are aligned and anchored; thin, dark line
- 41. reticulum, intricate system of tubules running parallel to and surrounding each myofibril; terminates as vesicles in the vicinity of the Z-lines
- 43. dark, corresponds with alignment of myosin filaments
- 45. fibrous connective tissue covers skeletal muscles and is contiguous with tendons at ends of muscles
- 46. globular heads that protrude away from the myosin filament at regular intervals
- 48. hundreds to thousands dominate sarcoplasm and contain the apparatus that contracts the muscle cell (1 um in diameter, 1/100 diameter of human hair)
- 49. connective tissue surrounding bundles of fibers
Down
- 1. proprioceptors located in tendons near the myotendinous junction and are in series, that is, attached end to end, with extrafusal muscle fibers
- 2. stroke, energy for pulling action; comes from hydrolysis
- 5. potential, electrical nerve impulse
- 7. center of each sarcomere (center of the H-zone) where adjacent myosin filaments anchor to each other
- 8. allow considerable movement (elbow and knee)
- 10. allow virtually no movement (sutures of skull)
- 11. bundles of muscle fibers under the epimysium (up to 150 fibers)
- 12. fibers, conduct impulses to all parts of the ventricles
- 13. process by skeletal muscle force is varied due to varying the number of motor units that are activated
- 14. node, intrinsic pacemaker; where rhythmic electrical impulses are normally initiated
- 15. protein which runs along the length of the actin filament in the groove of the double helix
- 16. heart muscle
- 19. connective tissue covering all bones)
- 20. joints, allow movement about all three perpendicular axes that define space (shoulder & hip)
- 21. unit, motor neuron + muscle fibers is innervates
- 24. pressure, pressure in the narrow space between the lung pleura and chest wall
- 26. bundle, conducts the impulse to the ventricles
- 27. cartilage, covers bone ends
- 29. iron-protein molecule carried by RBC to transport oxygen
- 30. spindles, proprioceptors that consist of several modified muscle fibers enclosed in a sheath of connective tissue
- 32. limited movement (intervertebral disks)
- 35. simple random motion of molecules moving in opposite directions through alveolar capillary membrane
- 37. the smallest contractile unit of skeletal muscle, consists of myosin and actin organized longitudinally (~2.2 um in length)
- 42. pressure, pressure inside the alveoli when the glottis is open and no air is flowing into or out of the lungs
- 43. node, where impulse is delayed slightly before passing into ventricles
- 44. joints, allow movement about two perpendicular axes (ankle & wrist)
- 47. light, corresponds with area in two adjacent sarcomeres that contain only actin filaments