I believe the tiny blood vessels are called capillaries, located in the lungs.
Capillaries are the small blood vessels where oxygen is exchanged for carbon dioxide. They are located throughout the body and allow for the exchange of gases between the blood and tissues.
Oxygen and carbon dioxide are exchanged across the lining of a frog's mouth. Oxygen is absorbed from the air into the blood vessels, while carbon dioxide is released into the air from the blood vessels.
When you inhale, your breath is drawn into your lungs, and is exchanged for Carbon Dioxide. The oxygen is 'traded' for Carbon Dioxide from your blood vessels, which leaves the body when you exhale. In other words, inhaling brings Oxygen to your blood.
Alveoli
The tiny air sacs in the lungs where oxygen and carbon dioxide are exchanged are called alveoli. They are surrounded by blood vessels through which gas exchange takes place during the process of respiration.
Arteries to arterioles to capillaries where exchange occurs. Oxygen and nutrients are exchanged for carbon dioxide and wastes.
CO2 exchanged to blood through capillaries and blood to alveoli
Oxygen is absorbed, and Carbon Dioxide is released.
The respiratory system removes carbon dioxide from the blood and brings oxygen into the blood. This process occurs through the lungs, where oxygen from the air is exchanged for carbon dioxide in the blood.
The capillary is the only blood vessel where things can be exchanged because it is so thin (one cell thick). Capillaries have a single cell layer of squamous epithilium.
alveolus
blood vessels