3. Set-up
-Clamp the femur in the femur clamp.
-Tie the Tendon of Achilles to the hook of the muscle lever.
-Connect in series a dry cell, simple key and inductorium for
single make and break shocks. This is the primary circuit.
-Connect a hand electrode to the secondary binding posts of
the inductorium. This is the secondary circuit producing an
induced current.
-Kymograph record not needed.
4.
5.
6.
7.
8. Experimental Procedures
1. Mechanical Stimulus:
• Pinch the nerve gently near its cut end using a pair of forceps.
2. Electrical Stimulus:
2.1 Using the weakest current possible, apply a hand electrode
near the free end of the nerve.
Stimulate the nerve using single break shocks.
Gradually increase the strength of the current until a definite
response is elicited in the muscle. Record the strength.
2.2 Place a ligature tightly around the nerve, midway between its
free end and the muscle.
Note if there is any response during tying.
2.3 Stimulate the free end of the nerve. Note the effect.
2.4 Stimulate the nerve between the ligature and the
gastrocnemius muscle.
Note the response of the muscle.
9. Results
PROCEDURE RESPONSE
Pinching the nerve ?????
Electrical stimulation ?????
While tying the nerve ?????
Stimulation of free end of nerve ?????
Stimulation of nerve between the
ligature and gastrocnemius muscle
?????
10. Results
PROCEDURE RESPONSE
Pinching the nerve Only part of the musculature
moved.
Electrical stimulation The whole part of the
gastrocnemius muscle moved.
While tying the nerve No response
Stimulation of free end of nerve No response
Stimulation of nerve between the
ligature and gastrocnemius muscle
The whole musculature moved.
(twitched)
11.
12.
13. Research Questions
1. What types of stimuli can be used in stimulating a tissue?
I. Mechanical Stimulus
II. Electrical Stimulus
14. Research Questions
2. Name and define the types of stimuli according to
quality and according to intensity?
-Homologous stimulus act specifically upon the nerve
terminations ion a specific end organ.
-Heterologous stimulus acts upon any part of sensory.
Mechanical- glass rod as stimulus
Electrical- using voltage as stimulus
15. Research Questions
3. What is the purpose of tying the nerve?
Tying the nerve blocks the stimulus.
16. Research Questions
4. What does this experiment prove regarding the nature
of conductivity in nerves and the conditions necessary
for this property?
Superficially on the cell membrane, nerve impulses are to be
found. Local current flows between the active and adjacent
areas, resulting in depolarization of the previously inactive
areas. In this way, the depolarization spreads away from its
point of origin.
17. Research Questions
5. What physiological properties are exhibited by the
nerve? Define each:
1. Excitability (Irritability): all cells responds to environmental
changes.(stimuli)
2. Conductivity : neurons respond to stimuli by producing
electrical signals that are quickly conducted to other cells at
distant.
3. Secretion : secretion of the neurotransmitter.
