HOW MUCH DOES AN ADULT BRAIN WEIGH? - ARTE - 2025

The weight of the brain of a human adult ranges between 1000 and 2000 grams, with the average being between 1300 and 1400 grams. This is a great weight in relation to the weight of the whole body. It represents a much greater relative weight compared to animals of similar weights, such as the ostrich or the lion, whose brains weigh 10 to 20 times less.

Its composition is 78% water, 10% fat and 8% protein. The main physical characteristic of the brain is its folds or convolutions. It involves part of the cerebral cortex, the outer covering of the brain.

These folds allow to increase the cerebral surface; if it were extended it would occupy a page spread out in a newspaper. The brain within the human being is well protected: it floats in the cerebrospinal fluid, which is within the subarachnoid space.

Are species with bigger brains more intelligent?

If you compare the brains of some species, you will find that those with greater brain capacities have greater cognitive abilities.

For example, the brains of mammals - such as primates or felines - are larger than those of insectivores and possess greater cognitive abilities.

However, this relationship is not always like this. For example, the brains of cows are larger than those of any species of monkey, but they are not as intelligent.

A much more obvious comparison is that of the human brain and that of the elephant.

The elephant's brain weighs on average 4,700 grams compared to 1,400 grams in humans.

Also, the brain of the sperm whale weighs 7,800 grams.

Obviously neither sperm whales nor elephants are cognitively superior to humans.

Is the human brain the largest in relation to the body?

Neither.

Although this belief continues to exist since the time of Aristotle, it is erroneous and there are data to corroborate it.

It is true that compared to an elephant the human brain-body ratio is enormous (1/40 of the human versus 1/560 of the elephant).

However, it is equal to that of the mouse (1/40) and smaller than that of some birds (1/12).

Other curiosities about the brain

-The human brain needs 20% of the body's oxygen

-It has approximately 86 billion neurons

-The brain needs 20% of the cerebral irrigation

-The brain receives 36 liters of blood every hour, 891 liters per day.

-The brain needs 8-12 glasses of water for its proper functioning.

-If the blood supply to the brain is interrupted, consciousness is lost in a few seconds.

-The cerebellum is the brain area that weighs the most, assuming up to 85% of the weight.

Average weight in other animals

Human adult - 1300 - 1400 grams

Newborn Human - 350-400 grams

Sperm whale - 7800 grams

Fin whale - 6930 grams

Orca - 5620 grams

Elephant - 4783 grams

Yubarta - 4675 grams

Gray whale - 4317 grams

Boreal whale - 2738 grams

Pilot whale 2670 grams

Bottlenose dolphin - 1500-1600 grams

Walrus - 1020 grams

Homo erectus - 850-1000 grams

Camel - 762 grams

Giraffe - 680 grams

Hippo - 582 grams

Leopard seal - 542 grams

Horse - 532 grams

Polar bear - 498 grams

Gorilla - 465-540 grams

Cow - 425 - 458 grams

Chimpanzee - 420 grams

Orangutan - 370 grams

Manatee - 360 grams

Tiger - 263 grams

Lion - 240 grams

Grzlly Bear - 234 grams

Pork - 180 grams

Jaguar - 157 grams

Sheep - 140 grams

Rhesus monkey - 90-97 grams

Aardvark - 72 grams

Dog - 72 grams

White shark - 34 grams

Cat - 30 grams

Rabbit - 10-13 grams

Aligator -8.4 grams

Didélfidos - 6 grams

Hamster - 1.4 grams

References

1. Blinkov, SM and Glezer, II The Human Brain in Figures and Tables. A Quantitative Handbook, New York: Plenum Press, 1968.
2. Demski, LS and Northcutt, RG The brain and cranial nerves of the white shark: an evolutionary perspective. In Great White Sharks. The Biology of Carcharodon carcharias, San Diego: Academic Press, 1996.
3. Nieuwenhuys, R., Ten Donkelaar, HJ and Nicholson, C. The Central Nervous System of Vertebrates. Vol. 3, Berlin: Springer, 1998.
4. Berta, A., et al. Marine Mammals. Evolutionary Biology, San Diego: Academic Press, 1999.
5. Mink, JW, Blumenschine, RJ and Adams, DB Ratio of central nervous system to body metabolism in vertebrates: its constancy and functional basis. Am. J. Physiology, 241: R203-R212, 1981.
6. Rehkamper, G., Frahm, HD and Zilles, K. Quantitative development of brain and brain structures in birds (Galliformes and Passeriforms) compared to that in mammals (Insectivares and Primates). Brain Beh. Evol., 37: 125-143, 1991.
7. Ridgway, SH and Harrison, S., Handbook of Marine Mammals, Vol. 3, London: Academic Press, 1985.
8. Shoshani, J., Kupsky, WJ and Marchant, GH, Elephant brain. Part I: Gross morphology functions, comparative anatomy, and evolution, Brain Res. Bulletin, 70: 124-157, 2006.