What is Human Body?
The human body is a complex biological system consisting of cells, tissues, organs and systems that work together to make a person.
Main Structures of Human body:
From the outside, the human body can be divided into several main structures. The head contains the brain that controls the body. The neck and trunk are home to many of the vital systems that keep the body functioning and healthy. The limbs, (arms and legs) help the body move and function in the world.
Senses
The human body has five main senses that it uses to communicate information about the outside world to the brain. These senses include sight (eyes), hearing (ears), smell (nose), taste (tongue), and touch (skin).
Organ Systems of Human Body:
The human body is made up of several organ systems. Each system is made up of organs and other body structures that work together to perform a specific function. Most scientists divide the body into 11 systems.
Skeletal System – The skeletal system is made up of bones, ligaments, and tendons. It supports the overall structure of the body and protects the organs.
Muscular System – The muscular system works closely with the skeletal system. Muscles help the body move and interact with the world.
Cardiovascular/Circulatory System – The circulatory system helps deliver nutrients throughout the body. It includes the heart, blood and blood vessels.
Digestive System – The digestive system helps convert food into nutrients and energy for the body. Some of the organs present in the digestive system are the stomach, small intestine, large intestine, liver, and pancreas.
Nervous System – The nervous system helps the body communicate and allows the brain to control various body functions. It includes the brain, spinal cord, and an extensive network of nerves.
Respiratory System – The respiratory system brings oxygen into the body through the lungs and trachea. It also removes carbon dioxide from the body.
Endocrine System – The endocrine system produces hormones that help regulate other body systems. It includes pancreas, adrenal gland, thyroid gland, pituitary gland, etc.
Urinary System – The urinary system uses the kidneys to filter blood and remove waste products. It includes the kidneys, bladder and urethra.
Immune/Lymphatic System – The lymphatic and immune systems work together to protect the body against disease.
Reproductive System – The reproductive system includes the sex organs that allow humans to bear children. The system is different for men and women.
Integumentary System – The sheath system helps to protect the body from the outside world. It includes skin, hair and nails.
Cells, Tissues, and Organs of Human Body:
Like all living things, the human body is made up of cells. There are different types of cells in the human body. When many similar cells work together to perform a function, they form a tissue. There are four main types of tissues in the human body including muscle tissue, connective tissue, epithelial tissue, and nervous tissue.
Organs are several independent parts of the body that perform special functions. They are made up of fabrics. Examples of organs include the eyes, heart, lungs, liver, and stomach.
Interesting Facts about the Human Body
The human body is made up of about 37 trillion cells.
The average human heart beats about 100,000 times a day. If you spread out the brain wrinkles, it would be the size of a pillowcase.
Fingernails grow much faster than toenails. Both are made up of a protein called keratin.
About 60% of the human body is made up of water.
The brain itself does not feel pain. The largest internal human organ is the small intestine.
Acid in the stomach is strong enough to dissolve some metals.
The left lung is usually about 10% smaller than the right lung. It is to make room for the heart.
Humans are born with 270 bones. Some of these bones fuse in adulthood for a total of 206 bones in the adult human body.