The story of the human body pdf
Respiratory System - The respiratory system brings oxygen into the body through the lungs and windpipe.It includes the brain, spinal cord, and a large network of nerves. Nervous System - The nervous system helps the body to communicate and allows the brain to control various functions of the body.
Some of the organs included in the digestive system are the stomach, small intestine, large intestine, liver, and pancreas. Digestive System - The digestive system helps to convert food into nutrients and energy for the body.It consists of the heart, blood, and blood vessels. Cardiovascular/Circulatory System - The circulatory system helps deliver nutrients throughout the body.Muscles help the body to move and interact with the world. Muscular System - The muscular system works closely with the skeletal system.It supports the overall structure of the body and protects the organs. Skeletal System - The skeletal system is made up of bones, ligaments, and tendons.Most scientists divide the body into 11 systems. Each system is made up of organs and other body structures that work together to perform a specific function. The human body consists of several organ systems. These senses include sight (eyes), hearing (ears) Hearing and the Ear, smell (nose), taste (tongue), and touch (skin). The human body has five main senses that it uses to convey information about the outside world to the brain. The limbs (arms and legs) help the body to move about and function in the world. The neck and trunk house many of the important systems that keep the body alive and healthy. The head houses the brain which controls the body. All of that is not just remote history but part of us now: our human body is inseparable from nature all around us, and is intertwined with the history of the universe.From the outside, the human body can be divided into several main structures. Our bodies are made of stardust, the burned out embers of stars that were released into the galaxy in massive explosions billions of years ago, mixed with atoms that formed only recently as ultrafast cosmic rays slammed into the Earth’s atmosphere. Ultimately, we are connected to the beginning of the universe. We are also intimately linked to the Sun’s nuclear furnace and to the solar wind, to collisions with asteroids, and to the cycles of the birth of stars and their deaths in cataclysmic supernovae.
We rebuild using elements captured from our surroundings, and are thereby connected to animals and plants around us, to the bacteria within us that help digest them, and to geological processes such as continental drift and volcanism here on the Earth. What persists over time is not fixed but merely a pattern in flux. The entire body continually rebuilds itself, time and again, using the food and water that flow through us as fuel and as construction material. We are quite literally not who we were years, weeks, or even days ago: our cells die and are replaced by new ones at an astonishing pace. The body that is with us all our lives is always changing. This book tells the fascinating story of what truly makes the human body. We rebuild using elements captured from our surroundings, and are thereby connected to animals and plants around us.