Water 61.6%
Proteins 17%
Fat 13.8%
Minerals 6.1%
Carbohydrates 1.5%
Percentage of chemical elements
65% Oxygen
Carbon 18%
Hydrogen 10%
Nitrogen 3%
Calcium 1.5%
Phosphorus 1%
Potassium 0.4%
Sulfur 0.3%
Sodium 0.2%
Magnesium 0.1%
Chlorine O, 1%
Iron (traces)
Iodine (traces)
Cell structure
The total number of cells is about 100 billion.
Every second 10 million cells are lost and another 10 million are produced; those of our skin are renewed every 4-8 days; those of the intestinal surface, every 4 days.
Many brain cells (neurons) remain throughout life and can reach more than one hundred years.
There are three categories of cells: germinal, somatic (most) and stem-cells.
There are also 220 cell types with different shapes, functions and sizes; the smallest is the sperm (0.05 mm long), the largest the ovule (0.14 mm in diameter)
In each ejaculation, between 200 and 400 million sperm are emitted.
Each cell experiences 100,000 chemical reactions per second.
There are 3.2 billion nucleic acids in the genes of a cell.
Each ovum and sperm contain 3 billion base pairs of DNA.
Several million cancer cells are generated daily, which the immune system eliminates.
Skeletal-muscular system
An adult has about 17 kilos of bones divided into 206 pieces; the largest, the femur, the smallest, the stirrup.
The skeleton is completely restructured every 10 years.
The column is formed by 33 vertebrae; the last one, coccyx, which we share with the apes, is the vestige of which thousands of years ago our ancestors had a tail and wandered on all fours.
The muscles represent 40% of the weight of a man or 20% of a woman.
The human body has about 650 individual muscles attached to the skeleton that allow movement.
The most voluminous muscle is the gluteus maximus; the strongest, the masseter; the most active, the eyepieces (they move more than 1 million times a day)
When we walk we use 200 muscles and we take about 200,000 steps every year; we walk about 150,000 km throughout our lives.
We blink twelve times every minute.
Nervous system
The energy consumption of the brain, in relation to the rest of the body, is 20%, and it needs 25% of the oxygen that a person assimilates.
It contains some 100,000 million neurons connected to each other and to other cells through billions of synapses.
The brain processes about 400 billion bits of information per second, but we are only conscious (sensation of being conscious) of about 2000 bits.
The human brain is capable of storing the information contained in 1,000 encyclopedias.
Memory in certain people reaches amazing records: Bhanddanta Victtabi Vumsa, in 1975, recited 16,000 pages of Buddhist texts and, in 1995, the Japanese Hiroyuki Goto recalled 42,195 decimal places of the pi number.
The brain recovers during sleep: we spend about 121 days a year sleeping
The widest nerve is the sciatic nerve (2 cm in diameter); the longest, the tibial (50 cm)
Nervous stimuli can circulate at speeds between 0.5 and 120 m / sec.
Cardiovascular system
The heart can pump from 6 liters of blood / minute (at rest) to 40 liters / minute (in movement)
It only takes 60 seconds to pump blood to every cell in the body.
The average heart "beats" about 94,000-100,000 times a day: 60-70 times / minute, 3,800-4,000 times / hour = about 35 million times a year.
The heart does not suffer from lacerations or suffer from cancer.
The blood is made up of red blood cells (4.5-6 million / mm3), white blood cells (5,000-10,000 / mm3) and platelets (250,000-350,000 / mm3)
An adult has about 5 liters of blood (90% is water)
We have a network of about 100,000 kilometers of blood vessels, including arteries, veins and capillaries.
The bone marrow produces 2 to 3 million red blood cells per second, which also disappear in the same proportion
The red blood cells, during their average life of about 120 days, make more than 40,000 trips through the body.
Heart disease is one of the main causes of death: between 30 and 40% of all deaths are caused by heart disease; 50% of people who suffer a myocardial infarction die immediately or a few days or hours of having it.
Respiratory system
The lung capacity is about 5 liters.
Adults breathe about 9,000,000 times a year or 15 times / minute (babies, 35 times / minute).
At rest we ventilate about 5-8 l / minute; but if an intense effort is made, breathe up to 40 l / minute.
To live we need about 510 liters of air every hour.
The fluids of a sneeze or the air from a coughing port can go out at a speed between 100 and 170 km / h, and contaminate an area of about 6-20 m3
