How does oxygen flow through the body?
The oxygen enters the bloodstream from the alveoli, tiny sacs in the lungs where gas exchange takes place (Figure below). The transfer of oxygen into the blood is through simple diffusion. While oxygen moves from the capillaries and into body cells, carbon dioxide moves from the cells into the capillaries.
Oxygen enters the lungs, then passes through the alveoli and into the blood. The oxygen is carried around the body in blood vessels. Carbon dioxide moves into the blood capillaries and is brought to the lungs to be released into the air during exhalation.
- The oxygenated blood then leaves the lungs through pulmonary veins, which return it to the left heart, completing the pulmonary cycle. This blood then enters the left atrium, which pumps it through the mitral valve into the left ventricle.
- Some of the carbon dioxide is transported dissolved in the plasma. Carbon dioxide then diffuses out of the red blood cell and into the lungs, where it is expired. Additionally, hydrogen ion is released from hemoglobin, thus allowing oxygen to bind to hemoglobin as blood flows through the lungs.
- Because brain cells will die if the supply of blood which carries oxygen is stopped, the brain has top priority for the blood. Even if other organs need blood, the body attempts to supply the brain with a constant flow of blood.
Red blood cells are very important as they carry oxygen from the lungs to every other cell in the body. They contain a molecule called haemoglobin. It is this molecule that picks up the oxygen from the lungs and transports the oxygen molecules throughout the body.
- Oxygen is transported in the blood in two ways: A small amount of O 2 (1.5 percent) is carried in the plasma as a dissolved gas. Most oxygen (98.5 percent) carried in the blood is bound to the protein hemoglobin in red blood cells. A fully saturated oxyhemoglobin (HbO 2) has four O 2 molecules attached.
- Hemoglobin: The protein inside red blood cells (a) that carries oxygen to cells and carbon dioxide to the lungs is hemoglobin (b). Hemoglobin is made up of four symmetrical subunits and four heme groups. Iron associated with the heme binds oxygen.
- The protein inside (a) red blood cells that carries oxygen to cells and carbon dioxide to the lungs is (b) hemoglobin. Hemoglobin is made up of four symmetrical subunits and four heme groups. Iron associated with the heme binds oxygen. It is the iron in hemoglobin that gives blood its red color.
Oxygen is absorbed by the blood capillaries from the lungs alveoli by diffusion while carbon-dioxide is absorbed by the lungs alveoli from blood capillaries by diffusion. Transport of oxygen and carbon-dioxide occurs with the help of respiratory pigment called hemoglobin.
- Ans. It is necessary in mammals and birds to separate oxygenated and de-oxygenated blood because this makes their circulatory system is more efficient and helps in maintaining constant body temperature.
- Plants have two different types of 'transport' tissue. Xylem transports water and solutes from the roots to the leaves, phloem transports food from the leaves to the rest of the plant. Transpiration is the process by which water evaporates from the leaves, which results in more water being drawn up from the roots.
- The amount of urine produced depends on the amount of excess water and dissolved wastes present in the body. Some other factors such as habitat of an organism and hormone such as Anti-diuretic hormone (ADH) also regulates the amount of urine produced.
Updated: 28th November 2019