The Brain
The brain is the center of the nervous system in all vertebrate, and most invertebrate, animals. Some primitive animals such as cnidarian and echinoderm have a decentralized nervous system without a brain, while sponges lack any nervous system at all....
size of the average cat is 5 centimeters in length and 30 gramGram
The gram , ; symbol g, is a Physical unit of mass.Originally defined as "the absolute weight of a volume of pure water equal to the cube of the hundredth part of a metre, and at the temperature of melting ice" , a gram is now defined as one one-thousandth of the SI base unit, the kilogram, or Scientific notation kg, which itself is...
s. Since the average cat is 60 cm long and 3.3 kg, the brain makes up 1/12 of its lengthLength
Length is the long dimension of any object. The length of a thing is the distance between its ends, its linear extent as measured from end to end....
and 1/110 of its massMass
In physical science, mass refers to the degree of acceleration a body acquires when subject to a force: bodies with greater mass are accelerated less by the same force....
. Thus, the average cat's brain accounts for 0.9 percent of its total body mass, compared to 2 percent of total body mass in the average humanHuman
A human being, also human or man, is a member of a species of bipedalism primates in the family Hominidae . Mitochondrial DNA evidence indicates that modern humans originated in east Africa about 200,000 years ago....
. The surface area of a cat's cerebral cortexCerebral cortex
The cerebral cortex is a structure within the brain that plays a key role in memory, attention, perceptual awareness, thought, language, and consciousness....
is approximately 83 cm². The modern human cerebral cortex is about 2500 cm².(*) Interestingly, cat brains have been shown to be more similar to human brains than other domesticated animals. According to researchers at Tufts University School of Veterinary Medicine, the physical structure of human brains and that of cats are very similar; they have the same lobes in the cerebral cortex (the "seat" of intelligence) as humans do. Human brains also function the same way, conveying data via identical neurotransmitters.