What I Know About The Human Body

It's been several years since we last studied the human body in science class, however, I can still remember several things about the human body. The body is entirely composed of cells, which have been the basis of study for much of this year and can be read about in depth in many posts of this blog. The outside of the body is covered by many layers of skin cells, which are resistant to water and can heal themselves if damaged. Underneath our skin, we have bones connected by mussels and tendons and cushioned by cartilage. These bones have marrow inside of them, and are made of calcium. Throughout our entire body runs a vital substance called blood. In the blood there are many small cells, included red blood cells, which carry oxygen to the rest of the body, and white blood cells which fight diseases and parasites in the body. The disease-fighting agents are part of the lymphatic system. This system runs a substance called lymph through the entire body, which fights diseases and is filtered in certain places called lymph nodes. Blood can have four major types: O, A, B or AB. These types are determined by the presence or absence of certain antigens. Blood can also be RH positive or RH negative. Blood types are determined by genetics. The red blood cells receive oxygen in the lungs. In the lungs the oxygen diffuses into the cell. The blood is pumped by the heart, which has four chambers. These chambers come in two types, atrium or ventricle. Blood is brought in or out of the heart by veins or arteries. The brain controls the body, is sends signals to various body parts, telling them how to behave and complete their functions. The brain can be damaged in various ways, and yet it can also survive the most extraordinary circumstances. There is the remarkable case of Phineas Gage, who was stabbed in the brain. A metal rod went entirely through his head. His frontal lobe was destroyed, and even though his personality was changed he still lived for a remarkable twelve years before dying from seizures. The brain is a remarkable part of the human body, which is remarkably unknown.

 The brain also controls the system which allows us to feel pain. This is done by nerves, which run throughout our bodies. They send signals to our brain, which make us feel pain. I know that when we eat food it travels down our esophagus into our stomach and through our intestines, where the food is broken down and nutrients are removed. This is the majority of what I know about the human body.