- The human body is made up of a head, neck, torso, two arms and two legs. The average height of an adult human is about 5 to 6 feet tall. The human body is made to stand erect, walk on two feet, use the arms to carry and lift, and has opposable thumbs (able to grasp).
- The adult body is made up of: 100 trillion cells, 206 bones,
600 muscles, and 22 internal organs.
- There are many systems in the human body:
- Circulatory System (heart, blood, vessels)
- Respiratory System (nose, trachea, lungs)
- Immune System (many types of protein, cells, organs, tissues)
- Skeletal System (bones)
- Excretory System (lungs, large intestine, kidneys)
- Urinary System (bladder, kidneys)
- Muscular System (muscles)
- Endocrine System (glands)
- Digestive System (mouth, esophogus, stomach, intestines)
- Nervous System (brain, spinal cord, nerves)
- Reproductive System (male and female reproductive organs)
- Every square inch of the human body has about 19 million skin cells.
- Every hour about 1 billion cells in the human body must be replaced.
- The average human head has about 100,000 hairs.
- The circulatory system of arteries, veins, and capillaries is about 60,000 miles long.
- The heart beats more than 2.5 billion times in an average lifetime.
- There are about 9,000 taste buds on the surface of the tongue, in the throat, and on the roof of the mouth.
- The strongest muscle in the body is the tongue.
- The human heart creates enough pressure when it pumps out to the body to squirt blood 30 feet.
- You blink over 10,000,000 times a year.
- The human brain weighs about 3 pounds.
- It takes about 20 seconds for a red blood cell to circle the whole body.
- Only 10% of the population are left handed.
- One fourth of the bones in your body are in your feet.
- Children tend to grow faster in the spring.
- The most sensitive finger on the human hand is the index finger.
- More men are color-blind than women.
- More people have brown eyes than any other color.