Where is the earthworms brain

Eating : Worms do not have teeth, but their mouths are muscular and strong. Nightcrawlers can even pull leaves into their burrows using their strong mouths. The front end of the worm, its prostomium , is pointed and firm, making it easy for worms to push their way into crevices as they eat their way through their burrows.

The mouth of the worm is just behind the prostomium. Worms swallow pieces of dirt and decaying leaves, and the food passes through the pharynx , located in body segments , the esophagus segments , and into the crop, which stores food temporarily. The worm's stomach is very muscular, so is called a gizzard. Like a bird's gizzard, it grinds up the food, which then moves into the intestine.

The intestine extends over two-thirds of the worm's body length. In the intestine, food is broken down into usable chemicals which are absorbed into the bloodstream. Leftover soil particles and undigested organic matter pass out of the worm through the rectum and anus in the form of castings , or worm poop. Worm poop is dark, moist, soil-colored, and very rich in nutrients.

That's why farmers and gardeners like to have lots of worms in their soil. Cleaning out the blood : Worms don't have kidneys, but they have something serving the same purpose. Worms have nephridia to filter out the dead cells and other wastes that are sloughed into the blood.

Wastes from the nephridia are eliminated through the same opening as the digestive wastes. Worm urine is more dilute than ours, but has ammonia as well as urea. Heartbeats : Worms don't have just one heart. They have FIVE! But their hearts and circulatory system aren't as complicated as ours -- maybe because their blood doesn't have to go to so many body parts.

This stage of the life cycle is located between the hatchling phase and the appearance of genital markings adult stage. Earthworms can enter into periods of inactivity or dormancy as a result of unfavourable conditions e. This is known as aestivation. During aestivation, the earthworm curls up into a knot and becomes quite pink.

The following table outlines the anatomical characteristics of earthworms: Characteristic. Bilateral Symmetry. If you cut an earthworm down the centre, you would find that the left and the right sides of its body are identical or symmetrical. Member of the class Oligochaeta. They crawl using circular and longitudinal muscles which are located under the epidermis Each segment also has bristle like setae see figure 1 which help to anchor their segments as they crawl.

Basic Respiratory System. Unlike humans, earthworms do not have a well-developed respiratory system Instead of lungs, they breathe through their skin which needs to stay moist for breathing. Closed Circulatory System. Unlike many other invertebrates, the circulatory system is fully closed One large blood vessel runs the length of the body, immediately beside the gut Two to five pairs of muscular blood vessels extend from the central vessel and function as hearts to drive the circulatory system.

But almost two thirds of the worm's nerve cells form a ring in the head region, where they make thousands of connections with each other.

This 'brain' is the control centre of the animal, where much of the sensing and decision-making takes place. Even though the brain is very compact, the animal displays a range of complex behaviours, and neuroscientists have been interested in understanding its brain for decades. Previous studies have created 'wiring diagrams' for the connections between nerve cells.

This latest study, though, is the first to provide the complete spatial coordinates to those circuit diagrams. Professor Netta Cohen, Computational Neuroscientist at the University of Leeds, who supervised the research, said: "The brain needs to organise information flow to control the animal's behaviour. But how the structure and function of the brain are related is an open question. Providing the spatial representation of the circuitry has allowed us to uncover the modular structure of this animal's brain.

The researchers used a legacy collection of electron microscope images of the brain of an adult and juvenile nematode worm. Those images revealed individual brain cells or neurons, allowing the researchers to map the organisation of the worms' neural circuits, from the level of individual cells through to the large scale architecture of the entire brain. The scientists identified known neural circuits and pathways within the brain such as a navigation neural circuit which an animal would use to follow smells and tastes to forage for food.

Another circuit is thought to facilitate mechano-sensation, so it would feel its way as it wriggles through the soil -- or sense if it is surrounded by bacteria. Their theory is that information is processed in the worm's brain through a number of 'layers'. In fact, a similar layered architecture is found in the human brain. Information flow starts in sensory cells, which respond to the environment. For example, cells may sense bacteria but are they the right bacteria to feed on -- do they smell like the 'right' bacteria?

The answer requires information to be integrated from multiple senses before being sent to the command area of the brain for action. Professor Cohen said: "The brain map reveals a very elegant structure to support information flow through a worm's brain and it is more sophisticated than the traditional view that simple animals follow a stimulus-response path. During their study, the researchers were surprised to discover the extent of individual variation in the worms' brains.