Diffusion due to differences in air pressures.

to allow gas exchange (oxygen and carbon dioxide)

The process is usually referred to as diffusion. This happens when concentrations in different areas interchange to give a more even mixture. Going through a membrane ( in this case the lung's alveoli wall ) would more properly require the process to be called osmosis, but that term is not usually used medically.

to provide them energy of some sort

The oxygen diffuses into the Red Blood Cells (RBCs) in the lungs. The blood goes to the heart and is pumped to the rest of the body. When the blood reaches oxygen deprived tissues, the oxygen moves from the RBCs to the tissues.

Probably what happens in every other part of the body, due to osmosis and dispersion, the oxogen goes out of the blood and nourishes the cells. Meanwhile the Carbon dioxide attaches to the hemoglobin and is carried back to the lung to be exhaled.

In order, your blood follows this general path as it is traveling from arteries to veins:

1. Conducting arteries (aorta)

2. Muscular arteries

3. Arterioles

4. Capillaries

5. Venules

6. Veins

Although ultra filtration in the kidney filters wastes such as nitrogenous waste products in the glomerulus from the blood, it also filters nutrients such as glucose and amino acids. Hence, the loop is surrounded by blood capillaries so that previously ultra filtrated nutrients such as amino acids, glucose, and other nutrients can now be reabsorbed back into the bloodstream by diffusion and active transport and not travel down the further kidney tubules which lead to the bladder and later be expelled in the form of urine.

Capillaries are tiny blood vessels which allow only very few blood cells to get through at a time. When blood cells enter the capillaries, the oxygen and nutrients which are stored in hemoglobin in the blood diffuse into the body. The exhausted blood cells then enter back into larger vessels to join the bloodstream once again. The cycle goes something like this:

Heart pumps blood --> blood cells pick up oxygen in alveoli in the lungs --> the heart pumps fresh blood through arteries to the body --> the arteries narrow down into capillaries in which aforementioned diffusion takes place --> capillaries grow back into veins which carry blood back to the heart and, ultimately, the lungs --> the process repeats.

Many people confuse veins with arteries. A vein is defined as a blood vessel which carried blood to the heart. MOST veins carry de-oxygenated blood; but not all. Once the depleted blood has passed through the heart, it goes to the lungs where it then goes back to the heart. The only vein which carries oxygenated blood in the one connecting the lungs and the heart. The same is inversely true for arteries; arteries carry blood away from the heart. MOST of this blood is full of oxygen; except for the blood in the artery going FROM the heart TO the lungs. This can be more easily understood by examining a diagram which I cannot attach with this answer.

You may be asking "Why does it look like my blood vessels are blue when I bleed red?" The blue vessels you are seeing are oxygen-depleted veins. When the protein, hemoglobin, is full of oxygen, it colors the blood cell red. So, the arteries in your body are red, because they are full of oxygen. As soon as your skin is broken, your blood cells are exposed to oxygen, thus causing them to instantly turn red. This is not perceptible to the human eye.

Capillary action is important for moving water (and all of the things that are dissolved in it) around. It is defined as the movement of water within the spaces of a porous material due to the forces of adhesion, cohesion, and surface tension.Plants and trees couldn't thrive without capillary action. The roots are capable of carrying water from the soil up into the plant.

One. Capillaries are only one epithelial cell thick

Your body overheats anytime heat (like heaters, the sun, fans, etc.) touches your skin. Remember that skin is a nerve. Whenever your skin is warm or hot. YOU are hot. That's why we sweat or else we will way overheat and we will die.

If you imagine your right arm as an artery and your left arm as a vein, then clasp your fingers together gently and imagine this is a capillary bed. Arterioles and venules come together in capillary beds and as oxygen is exchanged to surrounding tissue the blood from arteries is passed through the arterioles, through the venules and into the veins to return to the heart.

Check out the Wikipedia article in the related links, and look at the image on the right.

go to the body cells, after that it returns to the capillaries, but the fluid that doesn't diffuses into the lymph vessels (when it goes into the lymphatic vessels it's called lymph) and goes back to the heart.

They allow capillary walls to open and become leaky.

1.They are single cell thick

2.Thin film of moisture covering the alveoli allows the oxygen to dissolve in therefore making the process efficient

3. they have a large surface area

4.they are surrounded by network of blood capillaries maintaining the concentration gradient for the gaseous exchange

materials exchange between blood cells and blood

Capillaries must allow diffusion too allow for exchange of oxygen. Without oxygen, the eventual consequence would be death.

i dont knw sorryt6

i KNOW ONLY 2. They are : Carbon dioxide & excretory products

In the alveoli