the human body interactive map
Brain - Nervous system
Intestine - Digestive system
Gallbladder - Digestive system
Stomach - Digestive system
Kidneys - Digestive system
Liver - Digestive system
Heart - Circulatory system
Lungs - Respiratory system
Pancreas - Digestive system
Thyroid - Endocrine system
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Brain

What does it look like?
- the brain is protected by the bones of the skull and it is immersed in a liquid which protects it from shocks
- it weighs almost 1.5 Kgs. and it is formed by a soft rosy-grey tissue, wrinkled like a walnut
- it is divided into hemispheres and each of them controls the opposite of our body, the right hemisphere controls the left part
- it is rich in nerve cells
- it is divided into the brain, its biggest part, the cerebellum, much smaller and positioned in the back of the head, and the brain stem, acorn-shaped, which is inside the skull
How does it work?
- the thinking part of the nerve cells can be found towards the outside of the organ, in in a part called cerebral cortex, divided into different areas which receive messages and send instructions to the whole body
What' s its function?
- it allows us to think, feel, hear, see, smell and taste; it stores memories, emotions and sensations
- it allows us to learn, understand and have ideas.
Which organs is it linked to?
- it' s a powerful control network of our body, being connected to the spinal chord and to the nerves
Intestine

what does it look like?
- it' s a twisting tube almost 6 metres long that is located in the abdominal cavity
- it is divided into small (thinner) and large (wider) and it is surrounded by a membrane called peritoneus
how does it work?
- it is surrounded by layers of smooth muscles that contract slowly and rhythmically pushing forward little by little the food that is digested and absorbed
- digestion and absorption take place in the small intestine
- digestion is made possible by enzymes that break down food in particles that become smaller and smaller until they are absorbed by the intestine walls and carried to the blood
- the part that is not digested passes into the big intestine and it is then expelled from the body
what' s its function?
- its function is to digest and absorb food
which organs is it linked to?
- the duodenum (the first part of the small intestine) is connected to the liver and the pancreas through ducts where substances that are useful for digestion are released
Gallbladder

what does it look like?
- the gallbladder is a small pouch that sits just under the liver
- the gallbladder stores bile produced by the liver
- after meals, the gallbladder is empty and flat, like a deflated balloon
- before a meal, the gallbladder may be full of bile and about the size of a small pear
how does it work?
- in response to signals, the gallbladder squeezes stored bile into the small intestine through a series of tubes called ducts
what' s its function?
- bile helps digest fats, but the gallbladder itself is not essential
- removing the gallbladder in an otherwise healthy individual typically causes no observable problems with health or digestion yet there may be a small risk of diarrhea and fat malabsorption
which organs is it linked to?
- it is attached to your digestive system by a system of hollow ducts called the biliary tree
- the gallbladder sits in an indenture underneath the right lobe of the liver
Stomach

what does it look like?
- it is a part of the long digestive tube that runs from the mouth to the anus
- it is an expanded section of this tube, surrounded by a muscle layer
- it is J shaped and it is located in the chest cavity
- when empty, it has got a volume of 60 ml, when expanded it can contain more than two litres
how does it work?
- digestion is made possible by enzymes
- these chemical agents transform the complex molecules that can be found in the food into simpler molecules that can be absorbed by the blood
- the stomach produces two enzimes: pepsine, which decomposes proteins (meat, legumes etc), and rennine, present only in newborn babies, that makes milk more digestible.
what' s its function?
- its function is to store and trasform food.
which organs is it linked to?
- along the digestive tube, before the stomach there is the esophagus, which communicates with the stomach through a valve called cardias - after the stomach there is the duodenum (the first part of the small intestine), which is connected with the stomach through another valve, the pylorus
Kidneys

what do they look like?
- they look like two big beans, as big as a fist
- they are located behind the liver and the stomach, in the back of the abdominal cavity
how do they work?
- they filter our blood thanks to the nephrons, small filtering units that keep the useful substances and send them back to the blood, and form urine from water and wastes and send it to the bladder, from which it is expelled from the body
what' s their function?
- they eliminate the wastes present in the blood and they regulate the presence of salts and water in our body.
which organs are they linked to?
- they are linked to the bladder through the ureter
Liver

what does it look like?
- the liver is the biggest gland in our body
- it' s brown and it weighs almost 1.5 kilos
- it is divided into two lobes, the right lobe and the left lobe
- it is located in the chest cavity and its upper part touches the diaphragm
- it is formed by small grains called hepatic globules, and this is why its surface looks like an orange peel
how does it work?
- thanks to the action of the hepatocytes (hepatic cells) in the blood that flows here, the liver has 600 chemical functions.
what' s its function?
- it can be compared to a chemical factory which has 600 different roles in our metabolism, that is to say the chemical processes which take place in our body. Some of its functions are:
which organs is it linked to?
- it is linked to duodenal part of the small intestine through a duct called choledochus, which allows the bile to be poured into the liver
Heart

what does it look like?
- the heart, which is usually as big as a fist, looks like a big blood vessel (vein or artery) and it has very thick walls (myocardium)
- it is situated in the middle of the chest cavity (mediastinum), a little bit on the left, and it weighs around 250 grams
- it is surrounded by a fluid filled sac called the pericardium
- it is divided by a partition or septum into two halves, and the halves are in turn divided into four chambers:
- the 2 upper chambers are called atria
- two lower chambers are called ventricles
- the chambers are divided by the septum in a right and a left side, each with its own specific function
- in the right side atrium and ventricle are connected by the tricuspid valve and in the left side they are connected by the mitral valve
how does it work?
- the heart works as a pump for liquids and, contracting and relaxing thanks to electrical impulses, it helps supplying blood and oxygen to all parts of the body
Systole Phase: the ventricles contract and pump blood to the arteries
Diastole Phase: the heart ventricles are relaxed and the heart fills with blood
what' s its function
- it transports the most important elements for the life of cells (blood and oxygen) throughout the whole body
- the blood provides oxygen and it also gathers the metabolic waste of cells and takes it to the organs which eliminate it
which organs is it linked to?
- it is directly connected to all the big blood vessels, and to the lungs through the vena cava and the pulmonary artery
Lungs

what do they look like?
- the lungs are the main respiratory organs and they are located in the chest cavity
- they are elastic, pink and spongy
- they are surrounded by a thin two-layered membrane lining called pleura that protects them from rubbing against the ribs
- the two lungs are not identical, the left one is smaller than the right one and it weighs about 100 grams less
- the right lungs normally weighs 700 grams and the left 600
-the right lung is separated into three lobes (upper, medium and lower) while the left lung contains only two lobes
- in the back of the left lung there is a big cavity for the heart, called "the bed of the heart"
how do they work?
- they work in two phases:
Inhalation: the air reaches the lungs, the diaphragm contracts and moves downwards, the ribs and the sternum move upward and the lungs and the chest cavity expand
Exhalation: the air leaves the lungs, the diaphragm relaxes, the ribs and the sternum move downward and the lungs and the chest cavity reduce, resuming their normal size
what' s their function?
- they purify the venous blood that comes from the pulmonary artery and that will be sent back to the heart though the vena cava.
which organs are they linked to?
- they are linked to the heart through the vena cava and the pulmonary artery, and to the nose through the trachea and the bronchi
Pancreas

what does it look like?
- it is an oblong yellowish gland that is located behind the stomach
how does it work?
- Tiny islets formed by two different types of cells produce insulin and glucagon, two important hormones (chemical messangers) that regulate the quantity of sugar in the blood
- these two substances are released into the blood and reach the whole body
- the pancreas also produces a secretion rich in digestive enzymes (modificators of substances) that reaches the duodenum (the first part of the small intestine) through the pancreatic duct
what' s its function?
- it produces substances needed to digest food and to control the level of sugar in the blood
which organs is it linked to?
- it is linked to the duodenum through the pancreatic duct
Thyroid

what does it look like?
The thyroid is a butterfly-shaped gland that sits low on the front of the neck. Your thyroid lies below your Adam's apple, along the front of the windpipe. The thyroid has two side lobes, connected by a bridge (isthmus) in the middle. When the thyroid is its normal size, you can't feel it.
how does it work?
The function of the thyroid gland is to take iodine, found in many foods, and convert it into thyroid hormones: thyroxine (T4) and triiodothyronine (T3). Thyroid cells are the only cells in the body which can absorb iodine. These cells combine iodine and the amino acid tyrosine to make T3 and T4
what' s its function?
The thyroid gland is a vital hormone gland: it plays a major role in the metabolism, growth and development of the human body. It helps to regulate many body functions by constantly releasing a steady amount of thyroid hormones into the bloodstream.
which organs is it linked to?
circulatory system where are shared the hormones
Circulatory system

what is it?
- the cardiovascular system is basic to life and the beat of one's heart is an automatic function which is controlled by the brain
- the system transports nutrients and oxygen to the body's tissues and removes waste products from cells

how does it work?
Systemic circulation:
- from the main artery (aorta) through all the other arteries arterial blood reaches all the parts of the body
- after leaving oxygen and nutrients to all the cells and gathering carbon dioxide and other cell waste it reaches the heart through vein circulation
Pulmonary circulation:
- the blood passes through the venae cavae of the right atrium and then to the right ventricle, enters the pulmonary artery (lungs) and returns to the left atrium through the pulmonary vein
- from the left atrium it goes on to the left ventricle and reaches the aorta
which are its parts?
the cardiovascular system includes the heart and two networks of blood vessels:
- veins, which transport the blood that must be purified and oxygenated in the lungs
- arteries, which carry nutrient blood to the cells
Endocrine system

what is it?
- it is a system which collaborates with the nervous system to coordinate the activities of the human body
how does it work?
- the endocrine glands release in the blood more than 20 types of chemical messengers called hormones
- these hormones are carried to areas which are sensitive to the single hormone, called target tissues, where they have a long-lasting effect
- the small hypophysis controls all the other glands sending them the right hormones and it is in turn controlled by a part of the cerebellum called hypothalamus
which are its parts?
in our body there are six main endocrine glands:
- one in our head (hypophysis)
- one in our throat (thyroid and parathyroid)
- and four in our belly (suprarenal gland, pancreas, ovaries in women and testes in men)
Digestive system

what is it?
- it is the system that allows us to convert the food we eat into energy
how does it work?
- inside the mouth, teeth chop food into small pieces, which are moistened by saliva before the tongue and other muscles push the food into the pharynx
- while the bolus goes down, the epiglottis folds backwards to close the trachea and push it to the oesophagus, which leads to the stomach
- here the glands of the mucosa, stimulated by the vagus nerve, begin to produce gastric juices that transform the bolus into a semiliquid pulp, the chyme
- the vagus nerve also induces peristaltic movements in the stomach, where the chimo is mixed and digested thanks to powerful chemical substances
- the liver, the pancreas and the gall bladder take part in this process producing substances which make digestion easier
- the small intestine continues the digestive processes and absorbs the nutritious substances, while the large intestine is where the waste is stored and transformed into faeces
- so, during digestion the food changes its name: it is called bolus after the first mastication, chyme when it reaches the stomach, chyle during the intestinal phase
which are its parts?
the digestive system consists in a group of organs:
- the oesophagus (1) the first part of the long digestive tube, where the food moves before reaching the
- stomach (2)
- the liver (3)
- the gall bladder (4)
- the pancreas(5)
- the small intestine (6)
- the large intestine (7)
Excretory system

what is it?
- the life of our cells produces waste, and some of this waste is a real poison
- therefore these substances must be expelled from our body.
how does it work?
- the kidneys filter the blood, and as a result of this filtering process in the renal pelvis a liquid called urine is produced
- this liquid is carried through two small tubes called ureters to a kind of reservoir called bladder and it is expelled through the urethra
which are its parts?
- its parts are not only the kidneys, the bladder and the urethra that produce and expel urine
- but also the intestine that eliminates the digestion waste through the rectum, the lungs that expel carbon dyoxide and the skin that expels other waste and water in excess through sweat
Nervous system

what is it?
- it is the system that, together with the endocrine system, coordinates all the functions of our body
- it also allows us to relate to what is around us, receiving messages from the external world and giving appropriate answers
how does it work?
- the nervous cells are called neurons and they have several ramifications
- the nerves stem from the encephalon and from the spinal cord and they can be seen as a tight network of cables where electrical impulses constantly travel inward (for example the pick of a needle) and outward (pain)
which are its parts?
- it can be divided into three parts: encephalon, spinal cord and nerves
- in the encephalon there is the brain (two emispheres, limbic system, basal nuclei) and the encephalon trunk (medulla oblongata, bridge, cerebellum, diencephalon, which consists in thalamus and hypothalamus)
- the spinal cord is inside the spine and it is white on the outside and grey on the inside
- we have got 43 pairs of nerves: 12 cranial nerves (that start from the encephalon) and 31 spinal nerves (that start from the spinal cord)
- their tips are so thin and there are so many of them that it is impossible to find a single insensitive spot on our skin
Respiratory System

what is it?
- it is the system that allows us to get oxygen from the air inhaled in the lungs and to expel carbon dioxide through exhalation
how does it work?
- every time we inhale, air enters our nose or our mouth and, passing through the pharynx and the larynx, it goes down the long tracheal tube and inside two small galleries, the bronchi
- the bronchi lead into the lungs and they divide again into several other galleries which become smaller and smaller
- they are called bronchial tubes and in turn they split into many very small tubes which connect to more than 700 tiny sacs of spongy tissue, the alveoli, whose walls are very thin
- it is here that the exchange oxygen-carbon dioxide between blood and lungs takes place
- going through the lungs, the blood fills up with oxygen to be taken to the heart and it leaves the carbon dioxide which is removed from the lungs upon exhaling.
which are its parts?:
- the respiratory system's primary organs include the mouth, nose, pharynx, larynx, trachea, bronchi, lungs
Reproductive system

what is it?
- at the origin of a new life there is a sperm that fertilizes an egg
- in order for this to take place there must be sexual intercourse, the most intimate form of contact between a man and a woman
How does it work?
- when the penis delivers seminal liquid in the vagina, millions of sperms travel to the uterus until the Fallopian tubes
- if there they find a mature egg, it is possible that one of them penetrates it and fertilizes it, thus creating a new human being
which are its parts?
starting from the inside of the body, the organs of the female reproductive system are:
- the ovaries, which produce eggs (ova)
- the Fallopian tubes, which the eggs have to go through in order to reach the uterus
- the walls of the uterus (or womb), which become thicker to receive the fertilized egg
- the cervix
- the entrance of the uterus, the vagina
- the tube that leads from the uterus to the outside
the organs of the male reproductive system are:
- the bladder
- the prostate, which produces the liquid for sperm
- the urethra, through which sperm can go out the body
- the deferent duct, which leads the sperms produced by the testicles
- the testicles, which produce more than 500 million sperms a day
- the penis