In this BSL Spinal Cord Reflexes lesson, students examine properties of some simple neuromuscular reflexes commonly tested in physical diagnosis.
They will record and compare
- Subject’s contractile force vs. stimulus strength
- influence of the Jendrassik maneuver
- voluntary vs. involuntary (reflex) effector responses
- Achilles’ tendon reflex and patellar tendon reflex latent periods
Physicians and other clinicians test for the functional integrity of reflex pathways to obtain objective evidence regarding the function of muscles, peripheral nerves (motor and sensory), and the central nervous system. Conclusions drawn from testing reflexes are not the sole consideration in diagnosis but rather are considered in conjunction with other symptoms and signs of pathophysiology.
- To become familiar with anatomical and physiological elements of simple spinal reflexes.
- To examine properties of some simple neuromuscular reflexes commonly tested in physical diagnosis.
- To measure and compare latent periods and reaction times of extensor and flexor reflexes.
- To elicit an extensor reflex and compare contractile force vs. stimulus strength.
- To apply the Jendrassik maneuver and observe exaggeration of an extensor reflex.
- To measure and compare reaction times of voluntary activation of skeletal muscle vs. involuntary (reflex) activation of skeletal muscle.
Tasks Performed by the Student
Students will note the spinal cord reflexes in the following six scenarios:
- Knee Jerk Reflex—Subject sits with legs hanging at 90 degrees
- Knee Jerk Reflex—Subject sits and perform the Jendrassik maneuver
- Knee Jerk Reflex—Subject performs mental math with three-digit numbers
- Flexor Withdrawal Reflex—Subject is pricked by a pin or other cutaneous stimulus
- Voluntary Knee Jerk Reflex—Subject sits with eyes closed and voluntarily jerks the knee at the sound of the reflex hammer hitting a flat surface
- Ankle Jerk Reflex—Subject rests the knee and shin on the seat of a chair while Achilles tendon is struck
BSL Lessons are designed to allow at least four students to record and save data in a normal lab period (60-90 minutes). Typically, labs work most efficiently with three or more students working together at each BSL station.
BSL 4 L20 Spinal Cord Reflexes
Biopac Student Lab Student Download
This lesson requires a Biopac Student Lab (BSL) System and the following hardware: Reflex Hammer Transducer (SS36L); the response can be recorded with electrodes (such as EL503) and/or a goniometer (such as SS21L with TAPE1 adhesive). If your BSL System does not include all hardware items, expand your system by selecting the required items below. For more details, launch BSL or BSL Student to review the BSL Lab Manual for Lesson 20 Setup.
Offering the industry’s only system that delivers a comprehensive, 24-hour data logging solution in an easy-to-use, easy-to-wear package, the BioNomadix Logger® truly delivers “physiology anywhere.” The BioNomadix Logger is the perfect tool for applications that demand greater degrees of subject freedom and complex experimental design. BioNomadix Loggers wirelessly record physiological data as subjects freely and naturally […]
BIOPAC provides software and hardware that allows engineers to study the body. Here are a few notable studies using BIOPAC equipment for Biomedical Engineering research. Rehabilitating the Rehab Industry Could physical therapy be done from the comforts of your own home? If possible, this would open the door for more people with all sorts of ailments to […]
BIOPAC’s comprehensive Introductory ECG Guide addresses fundamental to advanced concerns to optimize electrocardiography data recording and analysis. Topics include: ECG Complex; Electrical and Mechanical Sequence of a Heartbeat; Systole and Diastole; Configurations for Lead I, Lead II, Lead III, 6-lead ECG, 12-lead ECG, precordial leads; Ventricular Late Potentials (VLPs); ECG Measurement Tools; Automated Analysis Routines for extracting, […]