Why Does A Leech Have 32 Brains
Leech is an annelid, which are catagorized by body segmenta. But unlike other annelids, its internal and external segmentation do not correspond each other. But physiologically because each ganglia control their respective segments,and usually work independently, you can also say that it have 32 brains!
What Is Humans Brain
Humans brain is a part of the central nervous system located in the skull. The main function of the humans brain is to control the functions of the body by integrating, processing, and coordinating the information to make decisions and send them to the effector organs. It is comparatively large; the human brain weighs around 1.2 kg. The main parts of the human brain are the cerebrum, the brainstem, and the cerebellum. The largest part of the humans brain is the cerebrum, which contains two cerebral hemispheres. The core of the cerebrum contains white matter while the outer layer or the cerebral cortex contains gray matter. Furthermore, neocortex and the allocortex are the two parts of the cerebral cortex.
Figure 1: Human Brain
Moreover, each brain hemisphere is made up of four lobes: frontal, temporal, parietal, and occipital lobes. Here, the front lobe is associated with some executive functions including self-control, planning, reasoning, and abstract thought. On the other hand, the temporal lobe is responsible for visual memory, language comprehension, and emotion association. Parietal lobe is responsible for spatial sense and navigation while occipital lobe serves as the visual processing complex. Although the left and the right hemispheres are similar in size and shape, the left hemisphere is responsible for functions including language while the right hemisphere is responsible for visual-spatial abilities.
Upper Limit On The Size Of The Head
Technically humans have two brains: One in the head, another in the stomach. The second brain basically regulates function of the digestive organs, or something. Maybe it can be thought of as an outpost of the first brain, a small outcropping of nerves that need to be “where the action is,” i.e. a field operation. Now imagine that evolution decides humans need to get smarter, but the head is already big enough to cause childbirth difficulties. The solution is that the second brain gets bigger, and is used for “multi-threaded computation.”
Also Check: Is Prevagen Safe For Diabetics
Other Fish In The Sea
To see if the jellyfish Cassiopea showed any signs of sleeping, a handful of Ph.D. students at the California Institute of Technology snuck into their lab at night tested the species for a few behaviors: reversible quiescence , an increased arousal threshold , and homeostatically-regulated quiescence;. The students tested that last one by pulsing water at the jellyfish every 20 minutes for a whole night. The next day, the jellyfish slept more heavily and behaved more strangely compared to;whats normal for them. The students in the journal Current Biology.
Their discovery shows that sleep could be a more fundamental process than we ever knewone that evolved very early on in the history of life on Earth, and one that plays an unclear role in most species. We know what sleep does , but we dont yet know why its absolutely necessary and why many animals spend so much time doing it. The gelatinous little swimmer known as Cassiopea could help us find out.
A Killer Whale Shuts Down Half Of Its Brain When Sleeping
Whales use half of their brains for sleeping and the other half for breathing. The part of the brain that controls breathing stays awake while the other half catches some z’s. Not only that, but the whale keeps one eye open and the other closed while sleeping. It’s called unihemispheric sleep, and dolphins, beluga whales, and sea lions do it, too!
Read Also: Can Propranolol Cause Memory Loss
List Of Animals By Number Of Neurons
The following are two lists of animals ordered by the size of their nervous system. The first list shows number of neurons in their entire nervous system, indicating their overall neural complexity. The second list shows the number of neurons in the structure that has been found to be representative of animal intelligence. The human brain contains 86 billion neurons, with 16 billion neurons in the cerebral cortex.
Which Animal Has Teeth In Its Stomach
Lobsters and crabs have teeth in their stomachs. These are used to crush its food, but they also have a strange secondary function in ghost crabs: making a noise that wards off predators. Believe it or not, lobsters, as well as other crustaceans such as crabs and crayfish, have teeth in their stomach!
Read Also: Does Fluoride Cause Brain Damage
This Animal Sleeps But Has No Brain
Some of Earths first animals might have just given scientists their first evidence that sleep is not what we think it is.
Receive emails about upcoming NOVA programs and related content, as well as featured reporting about current events through a science lens.
Jellyfish, which first arose about 700 million years ago, are great playgrounds for studying the evolution of sleep because of their ageand because they have a complex set of nerve cells but no brain.
Experts have always assumed that brains are;pre-requisites for sleep, since sleep is so intimately connected with memory, learning, and other neurobiological processes.;But sleeps enduring value over many millennia has remained a mystery. Sleep makes an organism vulnerable to attack. Plus, its time spent doing nothing as opposed to eating and building ones energy stores.
Heres Sarah Kaplan, reporting for The Washington Post:
Animals That Dont Have A Brain: Sea Sponges
Waste from the ocean helps sea sponges survive.
Among the animal kingdoms most primitive animals, the sea sponge stays relatively immobile. Its the water that moves them around and makes them look like theyre dancing. Their survival centers around filtering detritus from the ocean. They have no brains, organs, neurons, or tissue.
What the sea sponge has in common with humans is a genetic component that resembles synapses. Synapses use neurotransmitters to carry messages across the synaptic gap.
Heres another curious factoid about this animal: When a foreign object gets into their system, the creature draws in water and then squirts it out through a big sneeze. Thats a recent scientific discovery, and it implies that despite a lack of a brain, the sea sponge is aware of its ecosystem.
You May Like: Do Humans Only Use 10 Percent Of Their Brain
Which Animal Have Two Brains
While on the topic of animals and brains, we need to clarify that there are no animals which carry two distinct brains. The only time in which one can confirm an animal has two brains is if they are born with two heads, caused by a mutation. This is scientifically referred to as polycephaly.
If you want to read similar articles to Animals Without A Brain – Names & Characteristics, we recommend you visit our Facts about the animal kingdom category.
Animals With Multiple Brains
A creatures brain is a mass of nerve tissue that controls the rest of the body, the majority of animals have one brain. There are, however, several types of animals with multiple brains so to speak.;To clear up the confusion, it depends on how you look at it.
If you look at it anatomically, all animals have only one brain, but some species have sections known as ganglia, which function independently from the main brain. These ganglia can be split up into many different parts that operate independent of each other.
If you look at it in this manner, animals with such sections and hemispheres can be categorized as having multiple brains. This is because each ganglion functions autonomously.
There are several animals with more than one brain. So lets dive right in and have a look at 10 animals with multiple brains, then a few rare cases and couple of honorable mentions.
You May Like: Jahi Mcmath Decomposing
What Is Animals Brain
Animals brain is also part of the central nervous system, occurring in the head region. Based on the structure, three types of animals brains can be identified. They are the invertebrate brain, vertebrates brain, and mammals brain. Invertebrates brain includes the brain of mollusks, arthropods, worms, and tardigrades. Among them, the most complex brains occur in arthropods and mollusks. They are made up of twin parallel nerve cords that extend through the body. The supraesophageal ganglion serves as the arthropod brain and the brains of mollusks are the largest.
Figure 2: Animal and Human Brain
Furthermore, the three main parts of the vertebrate brain are prosencephalon , mesencephalon , and rhombencephalon . The six parts of the vertebrates brain are the telencephalon , diencephalon , mesencephalon , cerebellum, pons, and medulla oblongata. However, the main difference between vertebrates brain and mammals brain is the size. Also, the midbrain and the hindbrain of mammals are comparatively small while the forebrain is comparatively large. Humans and primates brain show massive expansion of the cerebral cortex, which in turns enhances their cognitive capacity.
Stomachs 32 Brains: A Visit To A Leech Farm
They were once used to treat everything from headaches to strangulation, and leeches are still a vital part of surgery
Six seconds. Perhaps 10. Twelve, if it is cautious or dopey. After that, the jaws will activate, the hundreds of teeth will engage, the leech will begin to eat, and its meal is your blood. Are you wading through a tropical pond in fierce humidity? Have you returned to your guesthouse to find with horror a passenger on your leg? Possibly. But you are equally likely to be in a sterile room of a modern hospital, tended by nurses who attach these bloodsucking animals to you without a shiver. You accept them equally calmly because it has been explained to you that these leeches may save your breast, or your finger, or your ear, or your life.
Less than half a mile from the M4 motorway, in the south-west of Wales, there is a walled entrance off a road whose name I cant pronounce, and a small sign saying Biopharm. A long and winding drive passes sheds of unclear purpose and ends in a small yard beyond an imposing cream-coloured manor house. The UKs only leech production business looks like a health farm. Which I suppose it is. Thousands of years since leeches were first employed for medicinal purposes, and a century since leech mania saw blood-letting used to tackle everything from headaches to strangulation, these creatures are still used to clean wounds and improve circulation, especially after surgery.
Dont Miss: How To Cancel Brainly Trial
Read Also: What Is Serotonin In The Brain
Dumbest Animals In The World: Turkey
One of the dumbest birds, the Turkey, was first domesticated by the Aztecs.
The Meleagris, or turkey, is a beloved food at least once a year. Many enjoy them as pets. And the entire world knows how much the turkey deserves to be on any list of dumbest bird. They have widely-spaced eyes and an almost clumsy, dim-witted walk. Benjamin Franklin called them birds of courage. Animal Planet says theyre confused, while The Washington Post attests these animals are just misunderstood.
Owners who love the bird have spoken of their turkey preferring to only drink water that drips upward. This phenomenon is the result of the bird consuming rain as it falls from the sky. But theyre not drinking. They simply have a tendency of staring into the sky for up to 30 minutes at a time. When it rains, it appears the birds are simply mesmerized at the idea of wetness coming out of nowhere. So, they stare with their mouths open in awe. Often, they do so until they drown.
You May Like: Why Do People Get Brain Freeze
Who Has The Smallest Human Brain
Researchers including those from IIIT Hyderabad developed the first Indian human brain atlas which revealed that India has some of the smallest brains in the world. The study found that there is a significant difference in the shape and size of the brain between Indians, Chinese, Koreans and Caucasians.
Also Check: Can Brain Freeze Cause Seizure
Why Do Animals Have Different Sized Hearts
Some animals have a small body and therefore their hearts are smaller too.
The main function of the heart is to pump the blood around the animals body. So for larger animals, we need a bigger pump in order to reach all the corners of the body with blood.
This also means that smaller animals with smaller bodies will have smaller hearts.
They dont need a strong pumping mechanism in order to direct the blood around their bodies.
Animals That Dont Have A Brain: Jellyfish
Jellyfish function using only sensory nerves.
Called jellies, this family of translucent creatures is unique. All other creatures without brains tend to be immobile, often spending their entire existence in a single spot. Jellyfish move with the ocean current. They also squirt water that can move them forward.
The jellyfish functions through a network of sensory nerves. Tentacles react to foreign objects with a shooting sting. That sting releases a toxin capable of neutralizing or killing the intruder.
Also Check: Fluoride Bad For Your Brain
Which Animals Have Two Brains
in special;circumstances animals are born with two heads or other mutations that cause anomalies like this. We also see this when siamese animals.
But how about animals that naturally live with two brains without it being an anomality?
No, we havent heard of such an animal. Some people argue that humans have two brains because the left and right parts of our brains are actually functioning separately.
They are connected by wires and obviously always work in close conjunction but they are actually two different pieces of meat.
Octopi Have Three Hearts:
Octopuses have three hearts.
They have a closed circulatory system like mammals that carries oxygen and nutrients around the body.
Lets take a closer look at what their hearts do:
You can read more about this and 17 Animals With Colorful Blood !
This weird looking fella is also an octopus and it is the Dumbo Octopus.
It will swallow its prey whole, so its not as friendly as it might look with the cute little fins on the sides.
We have added a few more images of octopi at the end of the post simply because we love how they look!
Bizarre Brains Of The Animal Kingdom
Wednesday, May 8, 2019
The ripples and folds of the brain are the source of all of our actions, emotions and instincts. While you may know what a human brain looks like, animal brains come in a variety of shapes and sizes.;Still, no matter what they look like,;all brains are made up of a grouping of nerve cells and act;as the;coordinating centre for sensation and actions.
Corvids Are Surprisingly Smart
The corvids have surprised scientists with their remarkable memory, their ability to employ complex social reasoning and their capacity to craft and use tools. Mr Bird, who is based at the department of zoology at Cambridge University and is supervised by Dr Nathan Emery, says: I would rate corvids as being as intelligent as primates in many ways.
The corvids are a group of birds that include: ravens, crows, jackdaws, jays, rooks, and magpies. They are very social birds who have the ability to identify individuals, form alliances and nurture relationships.
Recommended Reading: How To Cancel My Brainly Free Trial
You May Like: Cancel Brainly Account
How Do Brains Work
Research has shown how nerve cells function, passing electrical and chemical information at speeds up to 400 kilometres per hour. The scientific community has a good understanding of how these brain cells, or neurons, function on an individual level, passing signals from one neuron to the next. The big picture, however, is a mystery we havent fully solved yetdeciphering how these neurons coordinate by the millions to receive and send information simultaneously and linking all the bodys systems and organs to function as one unit. So, if you have brains on the brain, maybe neurological research is for you! There are countless mysteries in the animal brain just waiting to be solved.;
Animals That Dont Have A Brain: Sea Anemones
Sea anemone alter their shape in the water to adapt to their environment.
The sea anemone is yet another animal that has a plant-like appearance. However, the sea anemone is very much alive and seeking food, which it uses its long tentacles to catch and eat.
A unique characteristic of the sea anemone is its ability to alter shape. This act is accomplished by retracting and turning the long muscles in its tentacles. Its an amazing thing to see as they change form and shape while swaying in the water. Its indicative of how, despite the lack of a brain, animals can use sensors to react to their surroundings.
Recommended Reading: Why Does Brain Freeze Happen
Possibility : Managing Sleep Staying Awake
Another reason for multiple brains, as previously stated, would be to manage sleep:
Sleep? The body part needing sleep most is the brain. Now imagine a world where it’s too dangerous to go to sleep, maybe one with two suns or placed in a crowded part of the universe, so that there’s always enough light. Two brains might evolve to do a shift work.
Whilst this sleep-pattern eliminates this need for two-brained beings on earth, there is no reason why other alien organisms wouldn’t evolve two brains to conquer this problem: