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.