What is the structure of the human body

I believe that many friends have lived for so many years but have never had an in-depth understanding of the human body structure. In fact, the human body structure is very complex. It is very difficult to understand the human body structure overnight. However, we can still understand the general structure of the human body. In the following article, we will introduce to you in detail what the human body structure is like. I hope it will be helpful to everyone.

Nine systems

Digestive system, nervous system, musculoskeletal system, endocrine system, urinary system, reproductive system, circulatory system, respiratory system, immune system.

Chemical composition

Water makes up 65% of the human body weight. An adult weighing 70 kg will only have 25 kg left after dehydration, including 3 kg of carbohydrates, 7 kg of fat, 12 kg of protein and 3 kg of mineral salt.

blood

The total blood volume of the human body is about 8% of body weight. If blood loss exceeds 20% of the body's blood volume at one time, life activities will be hindered. Healthy people can generally recover quickly if they lose no more than 10% of their blood at a time.

muscle

There are approximately 639 muscles in the human body. It is composed of about 6 billion muscle fibers, the longest of which is 60 cm long and the shortest is only about 1 mm. Large muscles weigh 2000 grams, while small muscles weigh only a few grams. The average person's muscles account for 35%-40% of their body weight. The total length of capillaries in muscles can reach 100,000 kilometers, which is enough to circle the earth two and a half times.

brain

The brain is made up of about 14 billion cells, weighs about 1,400 grams, the cerebral cortex is about 2-3 mm thick, and the total area is about 2,200 square centimeters. It is estimated that 1,000 to 100,000 brain cells die every day (the less you use your brain, the more brain cells die). The information storage capacity of a person's brain is equivalent to that of 10,000 libraries with 10 million books each. Even the person who is best at using his or her brain only uses 10% of his or her brain capacity in his or her lifetime. The main component of the human brain is water, accounting for 80%. Although it only accounts for 2% of human body weight, its oxygen consumption accounts for 25% of the body's oxygen consumption, and its blood flow accounts for 15% of the heart's blood output. 2,000 liters of blood flow through the brain in a day. The energy consumed by the brain is equivalent to about 25 watts in electrical power.

In the above article, we introduced the human body structure. After reading the above article, I believe everyone has a preliminary understanding of the human body structure, but if we want to understand the human body structure in depth, we still need to continue exploring.