The+Human+Body

= The H﻿uman Body  =

By : Saurav S.
==== The human body is a very intricate and delicate machine. It contains many of the universe's wonders. The human body is comprised of several astounding systems and organs. The adult body is made up of 100 trillion cells, 206 bones, and 22 internal organs. A few of the human body systems are as follows. ====

==== One is the **//Nervous system//**. This includes the brain, spinal cord and many other nerves. The brain sends and receives many messages simultaneously. There are about 30 billion nerve cells in our body. A nerve cell can transmit 1000 nerve impulses each second. The spine gives and takes messages to and from the brain and nerves. The spinal cord is like a messenger. The nerves tell the body parts what to do. ====



====Another one is the //**Respiratory system**//. This system aids in breathing. The respiratory system includes the nose and lungs. The primary function of the respiratory system is to supply the blood with oxygen in order for the blood to deliver oxygen to all parts of the body. The respiratory system does this through breathing. When we breathe, we inhale oxygen and exhale carbon dioxide. This exchange of gases is the respiratory system's means of getting oxygen to the blood. Respiration is achieved through the mouth, nose, trachea, lungs, and diaphragm. Oxygen enters the respiratory system through the mouth and the nose. The oxygen then passes through the larynx (where speech sounds are produced) and the trachea which is a tube that enters the chest cavity. In the chest cavity, the trachea splits into two smaller tubes called the bronchi. Each bronchus then divides again forming the bronchial tubes. The bronchial tubes lead directly into the lungs where they divide into many smaller tubes which connect to tiny sacs called alveoli. The average adult's lungs contain about 600 million of these spongy, air-filled sacs that are surrounded by capillaries. The inhaled oxygen passes into the alveoli and then diffuses through the capillaries into the arterial blood. Meanwhile, the waste-rich blood from the veins releases its carbon dioxide into the alveoli. The carbon dioxide follows the same path out of the lungs when you exhale.==== ====The diaphragm's job is to help pump the carbon dioxide out of the lungs and pull the oxygen into the lungs. The diaphragm is a sheet of muscles that lies across the bottom of the chest cavity. As the diaphragm contracts and relaxes, breathing takes place. When the diaphragm contracts, oxygen is pulled into the lungs. When the diaphragm relaxes, carbon dioxide is pumped out of the lungs.====



==== The next important system is the **//Circulatory system//**. It helps to pump blood to all your body parts. It includes the heart and blood vessels. The heart is a very strong and important organ in a human body. Did you know the heart pumps 2,000 gallons of blood every day? Blood is needed for all of your body parts so that proves it is important. The blood vessels are important too because it needs to be some way for the blood to get to all your body parts. That is what the blood vessels do. Without it we would be a bag of blood. ====



The other significant system is the //**Digestive system**//. The digestive system is made up of the digestive tract. This system digests food and consists of the mouth, esophagus, stomach, large intestine, small intestine, rectum and anus. At the beginning of the process the food enters the mouth and is chewed by the teeth. Then it goes through the esophagus and into the stomach. There it is broken down into smaller particles with the help of various kinds of digestive enzymes and gastric juices and which will go to the small intestine. From there all digested nutrients and water get absorbed. These are sent to the bloodstream. Next, the undigested food, i.e, fiber and the dead cells of the stomach and intestinal walls go to the large intestine where they remain until the feces are expelled by the bowel movement. The water plays an important role in easy excretion.



==== The next vital system in a human body is the //**Musculoskeletal system**//. This includes bones and muscles.There are 206 bones in an adult's body! The bones help shape your body. Otherwise, you will look like an uncooked egg yolk. Almost 630 active muscles which act in groups help the bones to do their functions. If no muscles exist in you, you literally will be a bag of bones. ====



= Amazing facts of human body. =