In Accordance to its Responses to Different Stimuli1
September _ 2013
The brain is the most important part of an organism’s body. It is the one that receives all information from different stimuli and controls the movement of body parts. But for sudden stimuli that needs a quick response, spinal cord reflexes happened. The effect of decerebration on a toad (Bufo marinus) will cause its inability to move, but it still responded to stimuli because of certain reflexes which were not mediated by the brain. The intact toad’s response to certain stimuli was first observed. The same toad was decerebrated and took the same procedure. The result showed that the decerebrated …show more content…
Toads, frogs and salamanders are classified as amphibians. Class Amphibia, like other classes of phylum Chordata, has a nervous system that developed from an embryonic nerve cord. It is divided into three divisions: the central nervous system, the peripheral nervous system and the autonomic nervous system (Reyes, …show more content…
It is protected by the vertebral column composed of individual vertebrae and extend about 43 cm from the base of the brain to an inch or below the last rib. It brings impulses to and from the brain. It also communicates with and receives information from the rest of the body through 31 pairs of spinal nerves and without the interaction with the brain, handles reflexes. (Evangelista and Malonzo).
Reflexes, on the other hand, are immediate response to some stimuli, which come involuntary and is often not mediated by the higher center of the brain. Impulses enter the spinal cord through the dorsal root. Once in the spinal cord, electrical signals synapse with interneurons, which in turn transmit impulses to motor neurons and into the effector organs (Ocampo and Reyes). An organism can response to a certain stimuli even if its brain is damaged or slightly destroyed through the spinal cord reflex.
This shows that even if the toad( Bufo marinus)was decerebrated (only the brain was destroyed or damaged ), it can withdraw its limbs as the effect of acetic acid , maintain its proper posture , croak and swim because the spinal cord is still intact and can make reflexes. This study was conducted in Room A-137, Institute of Biological Sciences, UP Los Banos on September