Where do the oxygen in the blood come from?

When we breathe, the oxygen reaches our lungs via the mouth, nose, and trachea. The lungs have a member of very tiny cavities known as air sacs which are covered by a network of very fine blood vessels. An exchange of gases takes place here, Impure blood reaches these capillaries and releases the waste gas carbon dioxide in the air sacs. This is exhaled out of the body, and freshly inhaled oxygen is absorbed into the air sacs. This oxygen is released into the blood via the capillaries.

What are cells made of?

The different cells of our body have very different tasks, but they are all similar in their structure. They have a cell wall or a cell remembrance, which protects the inner matter of the cell and controls what goes in the cell and what comes out of it. The nucleus inside the cell controls all the processes int he cell. The energy for these processes comes from mitochondria, the power house of the cell. They are responsible for cell respiration. The endoplasmic reticulum takes care of the conversion of substances and for detoxifying the cells. Al these organelles are embedded in the liquid cytoplasm inside the cell. If we drink less fluids, the cytoplasm will dry out and the cell may die.

What are organs ?

Organs are parts of the body having specific tasks. An example is the intestine, in which food is broken down and the nutrients are absorbed in the blood. Another important organ is the liver, which utilizes the components of food. Other organs are the kidneys, the spleen, the heart, and our biggest organ, the skin. They are all made up fo different kinds of tissues, such as muscular tissue, fatty or supportive tissue, and blood vessels. The tissue in each organ is specifically designed to perform the task assigned to that organ. Thus, the muscular tissue of the heart is different and performs different functions as compared to that in the upper thigh. Each organ interacts with other organs ot keep the body healthy