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Frog Nervous System Knights of the Long Table
IntroductionWhy Frogs? show both primitive and advanced vertebrate
structures the position of their internal organs is similar to
that of humans they are small and readily available
In this particular study, frogs also have a highly developed nervous system (CNS,PNS, and ANS) similar to humans.
Introduction Nervous system
organ system that is responsible for conduction of impulses, coordination and integration of the various functions of the organs and receptor of stimuli
composed of a network of neurons that coordinate the actions of an animal and transmit signals between different parts of the body.
Introduction Neurons send signals to other cells
through electrochemical waves which travel along axons and cause the release of neurotransmitters.
Pithing a method where the brain or spinal cord is
damaged and results to loss of some stimuli responses of the animal
Introduction The experiment aims to compare the
stimuli responses of a normal frog from a decerebrated, brain pithed and double pithed frog.
Materials and methods Two frogs were prepared Five different stimuli• touch (hind toe) - forceps• electric shock (limbs) - electrode• heat (limbs) – soldering rod• chemical (belly) – 10% acetic acid• test for righting of the body - dissecting
pan• test for compensatory movement –
dissecting pan
ResultsSTIMULUS/ State
of FrogRESPONSES
Normal Decerebrated Spinal Totally-pithed
Touch + + + _Electric Shock + + + _
Heat + + + _Chemical + + + _
Righting the Body + + _ _Compensatory Movement + + _ _
+ = reactive - = non-reactive
Discussion The data gathered conform to the
expected results: normal and decerebrated frog
respond to all of the stimuli presented The brain pithed frog
only respond to touch, electric shock, heat and chemical stimuli
totally pithed frogwould not respond to any of the
stimuli.
Discussion The brain and spinal cord have varying
functions. The brain processes more complicated
stimuli compared to the spinal cord. The brain pithed frog loses its ability for
compensatory movement but does not lose its spinal reflexes.
Discussion• The brain and spinal cord coordinate their
actions. • The brain - much more complicated tasks • The spinal cord produces simple reflexes
which are necessary for survival.• Another function of the spinal cord is to
relay information to and from the brain while also generating basic patterns of locomotion.
Conclusion brain - interpretation of sensory
impulses, controls motor function (movement) and balance.
spinal cord - relays motor signals from the brain to the muscles of the body, and sensory information from the body to the brain.
SummaryFrog Part of CNS
destroyedFunctions lost
Normal None none
Decerebrated Forebrain of the brain
spontaneous movement; perception through touch;memory
Single pithed Brain only Ability for compensatory movement;Ability to remain upright/balance
Double pithed Both brain and spinal cord
All the ability to react to stimuli
Recommendation
Pithing must be done with less time.
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