This web is a large 'ball' of capillaries. The millions of tiny alveoli in the human lungs are a very effective adaptation which provides a huge surface area for gaseous exchange into and out of the blood. The alveoli have a very large surface area – in fact if all of the alveoli in your lungs were spread out flat they would cover the area of a tennis court.
This large surface area is the result of all the alveoli being small spheres – it is another example of the importance of the surface area: volume ratio.
what is around the wall of each air sac in the lungs is a web of what?
each air sac has tiny blood vessels around it.
Epithelium : epithelial cells form the linings of the body's organs and cavities, forming membranes and tubes and especially the lining of the lung's ALVEOLI (air sacs).
I don't know
Dingdongs
Capillaries
capillaries
Do not really know
capillaries
The diaphragm is a strong wall of muscle on the bottom of the chest cavity. As this wall of muscle expands downward, a vacuum is created which pulls air into the lungs. As the diaphragm returns to it's original position, air is pushed out of the lungs.
you breath it in and the air goes into your lungs and helps pump the blood around
Transitional arms
All of the air in the lungs gets exchanged with oxygen upon each breath. We exhale carbon dioxide and inhale oxygen.
Its around 30% left in the lungs
True
The diaphragm squeezes the air out of your lungs
Actually, air isn't forced into the lungs my the contraction of any muscle, but by the relaxation of the Diaphragm, along with the Intercostalis muscles on the ribs and the smooth muscle on the lungs. When your diaphragm contracts, it pushes air out of your lungs. When it relaxes, air is drawn in to the lungs. The intercostalis muscles also help move the ribs when the lungs move as your breath. There is one set on the ribs and one set in between each rib.Hope this helps!
Around the lungs,the blood is separated from the air inside each alveolus by only two cell layers; the cells making up the wall of the alveolus and the capillary wall itself. This is a distance of less than a thousandth of a millimetre. Because the air in the alveolus has a higer concentration of oxygen than the blood entering the capillary network, oxygen diffuses from the air across the wall of the alveolus and into the blood. That is why the distance is important.