ANATOMY

Detailed explanation-1: -In a process called diffusion, oxygen moves from the alveoli to the blood through the capillaries (tiny blood vessels) lining the alveolar walls. Once in the bloodstream, oxygen gets picked up by the hemoglobin in red blood cells.

Detailed explanation-2: -Red blood cells (RBCs) are a type of blood cell whose role is to transport oxygen from the lungs to the peripheral tissues of the body. Oxygen diffuses from the alveoli of the lungs into the RBCs, where it binds to hemoglobin. One molecule of hemoglobin can bind four molecules of oxygen (O2).

Detailed explanation-3: -Inside the red blood cell, oxygen reacts chemically with hemoglobin and is transported by both free and hemoglobin-facilitated diffusion. Oxygen diffuses through the cell membrane and is transported in blood plasma by free diffusion and by convection.

Detailed explanation-4: -When the red blood cells reach tissues that need oxygen, the oxygen is released from the haemoglobin and diffuses into the cells where it is used to make energy. All the systems in our body rely on oxygen to make energy.

Detailed explanation-5: -Oxygen moves by diffusion from an area of higher concentration inside the lungs to an area of lower concentration in the blood. It is then carried away by red blood cells. The blood leaving the lungs now has a high concentration of oxygen. It travels round the circulatory system to the cells in tissues and organs.