4. Five Essential Components to the Reflex Arc Figure 12.17

9. Reflex name How to elicit Response Centre Supinator jerk Radial styloid process Flexion of elbow C 5,6 Biceps Biceps tendon Flexion of elbow C 5,6 Triceps Triceps tendon Extension of elbow C 6,7 Knee jerk Patellar tendon Extension of Knee joint L 2,3,4 Ankle jerk Tendoachilis Plantar flexion of ankle L5, S1,2 Jaw jerk Chin Lower jaw goes up sharply Brain stem Planter reflex Scratching the outer border of the sole of the foot Planter flexion L 5, S1 Abdominal reflex Scratching over the abdomen Contraction T 7-12

10. 1. Monosynaptic Reflexes – patellar reflex

14. Muscle spindles are in parallel with extrafusal muscle fibers

15. Muscle spindle

17. Efferent innervation of skeletal muscles: Extrafusal fibers –  motor neurons Intrafusal fibers –  motor neurons

19. Sensory innervation of the muscle spindle

21. Role of  motor neurons – to increase the sensitivity of muscle spindles

24. Spindle responses to passive muscle stretch dynamic static

25. Primary spindle responses to passive stretch without and with  stimulation Primary = dynamic muscle spindle

26. Secondary responses to passive stretch without and with  stimulation Secondary = static muscle spindle

33. Golgi tendon organ Ib afferent

34. Excess muscle stretch (tension) fires Golgi tendon organ muscle spindle Golgi tendon organ

39. Stretch Reflex Figure 13.16

41. Stretch reflex

43. Gamma efferents allow continued response of spindle during voluntary contraction

45. Stretch reflex

47. Flexor reflex

49. Crossed extensor reflex

54. Autonomic Reflexes: “visceral reflexes” Figure 13-2: Autonomic reflexes

59. Knee Jerk Reflex: Stretch & Reciprocal Inhibition Reflexes : The knee jerk reflex

61. Flexion Reflex: Pull away from Painful Stimuli